copies-sdc: mark upgrade action as changelog only

We don't need to recompute the other revlog to add the changelog-v2 feature.

This simplify upgrade that use copies-sdc (as shown in the tests).

mercurial/upgrade_utils/actions.py

@@ -1,1100 +1,1103 b''
 # upgrade.py - functions for in place upgrade of Mercurial repository
 #
 # Copyright (c) 2016-present, Gregory Szorc
 #
 # This software may be used and distributed according to the terms of the
 # GNU General Public License version 2 or any later version.
 
 
 from ..i18n import _
 from .. import (
     error,
     localrepo,
     pycompat,
     requirements,
     revlog,
     util,
 )
 
 from ..utils import compression
 
 if pycompat.TYPE_CHECKING:
     from typing import (
         List,
         Type,
     )
 
 
 # list of requirements that request a clone of all revlog if added/removed
 RECLONES_REQUIREMENTS = {
     requirements.GENERALDELTA_REQUIREMENT,
     requirements.SPARSEREVLOG_REQUIREMENT,
     requirements.REVLOGV2_REQUIREMENT,
     requirements.CHANGELOGV2_REQUIREMENT,
 }
 
 
 def preservedrequirements(repo):
     preserved = {
         requirements.SHARED_REQUIREMENT,
         requirements.NARROW_REQUIREMENT,
     }
     return preserved & repo.requirements
 
 
 FORMAT_VARIANT = b'deficiency'
 OPTIMISATION = b'optimization'
 
 
 class improvement:
     """Represents an improvement that can be made as part of an upgrade."""
 
     ### The following attributes should be defined for each subclass:
 
     # Either ``FORMAT_VARIANT`` or ``OPTIMISATION``.
     # A format variant is where we change the storage format. Not all format
     # variant changes are an obvious problem.
     # An optimization is an action (sometimes optional) that
     # can be taken to further improve the state of the repository.
     type = None
 
     # machine-readable string uniquely identifying this improvement. it will be
     # mapped to an action later in the upgrade process.
     name = None
 
     # message intended for humans explaining the improvement in more detail,
     # including the implications of it ``FORMAT_VARIANT`` types, should be
     # worded
     # in the present tense.
     description = None
 
     # message intended for humans explaining what an upgrade addressing this
     # issue will do. should be worded in the future tense.
     upgrademessage = None
 
     # value of current Mercurial default for new repository
     default = None
 
     # Message intended for humans which will be shown post an upgrade
     # operation when the improvement will be added
     postupgrademessage = None
 
     # Message intended for humans which will be shown post an upgrade
     # operation in which this improvement was removed
     postdowngrademessage = None
 
     # By default we assume that every improvement touches requirements and all revlogs
 
     # Whether this improvement touches filelogs
     touches_filelogs = True
 
     # Whether this improvement touches manifests
     touches_manifests = True
 
     # Whether this improvement touches changelog
     touches_changelog = True
 
     # Whether this improvement changes repository requirements
     touches_requirements = True
 
     # Whether this improvement touches the dirstate
     touches_dirstate = False
 
     # Can this action be run on a share instead of its mains repository
     compatible_with_share = False
 
 
 allformatvariant = []  # type: List[Type['formatvariant']]
 
 
 def registerformatvariant(cls):
     allformatvariant.append(cls)
     return cls
 
 
 class formatvariant(improvement):
     """an improvement subclass dedicated to repository format"""
 
     type = FORMAT_VARIANT
 
     @staticmethod
     def fromrepo(repo):
         """current value of the variant in the repository"""
         raise NotImplementedError()
 
     @staticmethod
     def fromconfig(repo):
         """current value of the variant in the configuration"""
         raise NotImplementedError()
 
 
 class requirementformatvariant(formatvariant):
     """formatvariant based on a 'requirement' name.
 
     Many format variant are controlled by a 'requirement'. We define a small
     subclass to factor the code.
     """
 
     # the requirement that control this format variant
     _requirement = None
 
     @staticmethod
     def _newreporequirements(ui):
         return localrepo.newreporequirements(
             ui, localrepo.defaultcreateopts(ui)
         )
 
     @classmethod
     def fromrepo(cls, repo):
         assert cls._requirement is not None
         return cls._requirement in repo.requirements
 
     @classmethod
     def fromconfig(cls, repo):
         assert cls._requirement is not None
         return cls._requirement in cls._newreporequirements(repo.ui)
 
 
 @registerformatvariant
 class fncache(requirementformatvariant):
     name = b'fncache'
 
     _requirement = requirements.FNCACHE_REQUIREMENT
 
     default = True
 
     description = _(
         b'long and reserved filenames may not work correctly; '
         b'repository performance is sub-optimal'
     )
 
     upgrademessage = _(
         b'repository will be more resilient to storing '
         b'certain paths and performance of certain '
         b'operations should be improved'
     )
 
 
 @registerformatvariant
 class dirstatev2(requirementformatvariant):
     name = b'dirstate-v2'
     _requirement = requirements.DIRSTATE_V2_REQUIREMENT
 
     default = False
 
     description = _(
         b'version 1 of the dirstate file format requires '
         b'reading and parsing it all at once.\n'
         b'Version 2 has a better structure,'
         b'better information and lighter update mechanism'
     )
 
     upgrademessage = _(b'"hg status" will be faster')
 
     touches_filelogs = False
     touches_manifests = False
     touches_changelog = False
     touches_requirements = True
     touches_dirstate = True
     compatible_with_share = True
 
 
 @registerformatvariant
 class dirstatetrackedkey(requirementformatvariant):
     name = b'tracked-hint'
     _requirement = requirements.DIRSTATE_TRACKED_HINT_V1
 
     default = False
 
     description = _(
         b'Add a small file to help external tooling that watch the tracked set'
     )
 
     upgrademessage = _(
         b'external tools will be informated of potential change in the tracked set'
     )
 
     touches_filelogs = False
     touches_manifests = False
     touches_changelog = False
     touches_requirements = True
     touches_dirstate = True
     compatible_with_share = True
 
 
 @registerformatvariant
 class dotencode(requirementformatvariant):
     name = b'dotencode'
 
     _requirement = requirements.DOTENCODE_REQUIREMENT
 
     default = True
 
     description = _(
         b'storage of filenames beginning with a period or '
         b'space may not work correctly'
     )
 
     upgrademessage = _(
         b'repository will be better able to store files '
         b'beginning with a space or period'
     )
 
 
 @registerformatvariant
 class generaldelta(requirementformatvariant):
     name = b'generaldelta'
 
     _requirement = requirements.GENERALDELTA_REQUIREMENT
 
     default = True
 
     description = _(
         b'deltas within internal storage are unable to '
         b'choose optimal revisions; repository is larger and '
         b'slower than it could be; interaction with other '
         b'repositories may require extra network and CPU '
         b'resources, making "hg push" and "hg pull" slower'
     )
 
     upgrademessage = _(
         b'repository storage will be able to create '
         b'optimal deltas; new repository data will be '
         b'smaller and read times should decrease; '
         b'interacting with other repositories using this '
         b'storage model should require less network and '
         b'CPU resources, making "hg push" and "hg pull" '
         b'faster'
     )
 
 
 @registerformatvariant
 class sharesafe(requirementformatvariant):
     name = b'share-safe'
     _requirement = requirements.SHARESAFE_REQUIREMENT
 
     default = True
 
     description = _(
         b'old shared repositories do not share source repository '
         b'requirements and config. This leads to various problems '
         b'when the source repository format is upgraded or some new '
         b'extensions are enabled.'
     )
 
     upgrademessage = _(
         b'Upgrades a repository to share-safe format so that future '
         b'shares of this repository share its requirements and configs.'
     )
 
     postdowngrademessage = _(
         b'repository downgraded to not use share safe mode, '
         b'existing shares will not work and needs to'
         b' be reshared.'
     )
 
     postupgrademessage = _(
         b'repository upgraded to share safe mode, existing'
         b' shares will still work in old non-safe mode. '
         b'Re-share existing shares to use them in safe mode'
         b' New shares will be created in safe mode.'
     )
 
     # upgrade only needs to change the requirements
     touches_filelogs = False
     touches_manifests = False
     touches_changelog = False
     touches_requirements = True
 
 
 @registerformatvariant
 class sparserevlog(requirementformatvariant):
     name = b'sparserevlog'
 
     _requirement = requirements.SPARSEREVLOG_REQUIREMENT
 
     default = True
 
     description = _(
         b'in order to limit disk reading and memory usage on older '
         b'version, the span of a delta chain from its root to its '
         b'end is limited, whatever the relevant data in this span. '
         b'This can severly limit Mercurial ability to build good '
         b'chain of delta resulting is much more storage space being '
         b'taken and limit reusability of on disk delta during '
         b'exchange.'
     )
 
     upgrademessage = _(
         b'Revlog supports delta chain with more unused data '
         b'between payload. These gaps will be skipped at read '
         b'time. This allows for better delta chains, making a '
         b'better compression and faster exchange with server.'
     )
 
 
 @registerformatvariant
 class persistentnodemap(requirementformatvariant):
     name = b'persistent-nodemap'
 
     _requirement = requirements.NODEMAP_REQUIREMENT
 
     default = False
 
     description = _(
         b'persist the node -> rev mapping on disk to speedup lookup'
     )
 
     upgrademessage = _(b'Speedup revision lookup by node id.')
 
 
 @registerformatvariant
 class copiessdc(requirementformatvariant):
     name = b'copies-sdc'
 
     _requirement = requirements.COPIESSDC_REQUIREMENT
 
     default = False
 
     description = _(b'Stores copies information alongside changesets.')
 
     upgrademessage = _(
         b'Allows to use more efficient algorithm to deal with ' b'copy tracing.'
     )
 
+    touches_filelogs = False
+    touches_manifests = False
+
 
 @registerformatvariant
 class revlogv2(requirementformatvariant):
     name = b'revlog-v2'
     _requirement = requirements.REVLOGV2_REQUIREMENT
     default = False
     description = _(b'Version 2 of the revlog.')
     upgrademessage = _(b'very experimental')
 
 
 @registerformatvariant
 class changelogv2(requirementformatvariant):
     name = b'changelog-v2'
     _requirement = requirements.CHANGELOGV2_REQUIREMENT
     default = False
     description = _(b'An iteration of the revlog focussed on changelog needs.')
     upgrademessage = _(b'quite experimental')
 
     touches_filelogs = False
     touches_manifests = False
 
 
 @registerformatvariant
 class removecldeltachain(formatvariant):
     name = b'plain-cl-delta'
 
     default = True
 
     description = _(
         b'changelog storage is using deltas instead of '
         b'raw entries; changelog reading and any '
         b'operation relying on changelog data are slower '
         b'than they could be'
     )
 
     upgrademessage = _(
         b'changelog storage will be reformated to '
         b'store raw entries; changelog reading will be '
         b'faster; changelog size may be reduced'
     )
 
     @staticmethod
     def fromrepo(repo):
         # Mercurial 4.0 changed changelogs to not use delta chains. Search for
         # changelogs with deltas.
         cl = repo.changelog
         chainbase = cl.chainbase
         return all(rev == chainbase(rev) for rev in cl)
 
     @staticmethod
     def fromconfig(repo):
         return True
 
 
 _has_zstd = (
     b'zstd' in util.compengines
     and util.compengines[b'zstd'].available()
     and util.compengines[b'zstd'].revlogheader()
 )
 
 
 @registerformatvariant
 class compressionengine(formatvariant):
     name = b'compression'
 
     if _has_zstd:
         default = b'zstd'
     else:
         default = b'zlib'
 
     description = _(
         b'Compresion algorithm used to compress data. '
         b'Some engine are faster than other'
     )
 
     upgrademessage = _(
         b'revlog content will be recompressed with the new algorithm.'
     )
 
     @classmethod
     def fromrepo(cls, repo):
         # we allow multiple compression engine requirement to co-exist because
         # strickly speaking, revlog seems to support mixed compression style.
         #
         # The compression used for new entries will be "the last one"
         compression = b'zlib'
         for req in repo.requirements:
             prefix = req.startswith
             if prefix(b'revlog-compression-') or prefix(b'exp-compression-'):
                 compression = req.split(b'-', 2)[2]
         return compression
 
     @classmethod
     def fromconfig(cls, repo):
         compengines = repo.ui.configlist(b'format', b'revlog-compression')
         # return the first valid value as the selection code would do
         for comp in compengines:
             if comp in util.compengines:
                 e = util.compengines[comp]
                 if e.available() and e.revlogheader():
                     return comp
 
         # no valide compression found lets display it all for clarity
         return b','.join(compengines)
 
 
 @registerformatvariant
 class compressionlevel(formatvariant):
     name = b'compression-level'
     default = b'default'
 
     description = _(b'compression level')
 
     upgrademessage = _(b'revlog content will be recompressed')
 
     @classmethod
     def fromrepo(cls, repo):
         comp = compressionengine.fromrepo(repo)
         level = None
         if comp == b'zlib':
             level = repo.ui.configint(b'storage', b'revlog.zlib.level')
         elif comp == b'zstd':
             level = repo.ui.configint(b'storage', b'revlog.zstd.level')
         if level is None:
             return b'default'
         return bytes(level)
 
     @classmethod
     def fromconfig(cls, repo):
         comp = compressionengine.fromconfig(repo)
         level = None
         if comp == b'zlib':
             level = repo.ui.configint(b'storage', b'revlog.zlib.level')
         elif comp == b'zstd':
             level = repo.ui.configint(b'storage', b'revlog.zstd.level')
         if level is None:
             return b'default'
         return bytes(level)
 
 
 def find_format_upgrades(repo):
     """returns a list of format upgrades which can be perform on the repo"""
     upgrades = []
 
     # We could detect lack of revlogv1 and store here, but they were added
     # in 0.9.2 and we don't support upgrading repos without these
     # requirements, so let's not bother.
 
     for fv in allformatvariant:
         if not fv.fromrepo(repo):
             upgrades.append(fv)
 
     return upgrades
 
 
 def find_format_downgrades(repo):
     """returns a list of format downgrades which will be performed on the repo
     because of disabled config option for them"""
 
     downgrades = []
 
     for fv in allformatvariant:
         if fv.name == b'compression':
             # If there is a compression change between repository
             # and config, destination repository compression will change
             # and current compression will be removed.
             if fv.fromrepo(repo) != fv.fromconfig(repo):
                 downgrades.append(fv)
             continue
         # format variant exist in repo but does not exist in new repository
         # config
         if fv.fromrepo(repo) and not fv.fromconfig(repo):
             downgrades.append(fv)
 
     return downgrades
 
 
 ALL_OPTIMISATIONS = []
 
 
 def register_optimization(obj):
     ALL_OPTIMISATIONS.append(obj)
     return obj
 
 
 class optimization(improvement):
     """an improvement subclass dedicated to optimizations"""
 
     type = OPTIMISATION
 
 
 @register_optimization
 class redeltaparents(optimization):
     name = b're-delta-parent'
 
     type = OPTIMISATION
 
     description = _(
         b'deltas within internal storage will be recalculated to '
         b'choose an optimal base revision where this was not '
         b'already done; the size of the repository may shrink and '
         b'various operations may become faster; the first time '
         b'this optimization is performed could slow down upgrade '
         b'execution considerably; subsequent invocations should '
         b'not run noticeably slower'
     )
 
     upgrademessage = _(
         b'deltas within internal storage will choose a new '
         b'base revision if needed'
     )
 
 
 @register_optimization
 class redeltamultibase(optimization):
     name = b're-delta-multibase'
 
     type = OPTIMISATION
 
     description = _(
         b'deltas within internal storage will be recalculated '
         b'against multiple base revision and the smallest '
         b'difference will be used; the size of the repository may '
         b'shrink significantly when there are many merges; this '
         b'optimization will slow down execution in proportion to '
         b'the number of merges in the repository and the amount '
         b'of files in the repository; this slow down should not '
         b'be significant unless there are tens of thousands of '
         b'files and thousands of merges'
     )
 
     upgrademessage = _(
         b'deltas within internal storage will choose an '
         b'optimal delta by computing deltas against multiple '
         b'parents; may slow down execution time '
         b'significantly'
     )
 
 
 @register_optimization
 class redeltaall(optimization):
     name = b're-delta-all'
 
     type = OPTIMISATION
 
     description = _(
         b'deltas within internal storage will always be '
         b'recalculated without reusing prior deltas; this will '
         b'likely make execution run several times slower; this '
         b'optimization is typically not needed'
     )
 
     upgrademessage = _(
         b'deltas within internal storage will be fully '
         b'recomputed; this will likely drastically slow down '
         b'execution time'
     )
 
 
 @register_optimization
 class redeltafulladd(optimization):
     name = b're-delta-fulladd'
 
     type = OPTIMISATION
 
     description = _(
         b'every revision will be re-added as if it was new '
         b'content. It will go through the full storage '
         b'mechanism giving extensions a chance to process it '
         b'(eg. lfs). This is similar to "re-delta-all" but even '
         b'slower since more logic is involved.'
     )
 
     upgrademessage = _(
         b'each revision will be added as new content to the '
         b'internal storage; this will likely drastically slow '
         b'down execution time, but some extensions might need '
         b'it'
     )
 
 
 def findoptimizations(repo):
     """Determine optimisation that could be used during upgrade"""
     # These are unconditionally added. There is logic later that figures out
     # which ones to apply.
     return list(ALL_OPTIMISATIONS)
 
 
 def determine_upgrade_actions(
     repo, format_upgrades, optimizations, sourcereqs, destreqs
 ):
     """Determine upgrade actions that will be performed.
 
     Given a list of improvements as returned by ``find_format_upgrades`` and
     ``findoptimizations``, determine the list of upgrade actions that
     will be performed.
 
     The role of this function is to filter improvements if needed, apply
     recommended optimizations from the improvements list that make sense,
     etc.
 
     Returns a list of action names.
     """
     newactions = []
 
     for d in format_upgrades:
         if util.safehasattr(d, '_requirement'):
             name = d._requirement
         else:
             name = None
 
         # If the action is a requirement that doesn't show up in the
         # destination requirements, prune the action.
         if name is not None and name not in destreqs:
             continue
 
         newactions.append(d)
 
     newactions.extend(o for o in sorted(optimizations) if o not in newactions)
 
     # FUTURE consider adding some optimizations here for certain transitions.
     # e.g. adding generaldelta could schedule parent redeltas.
 
     return newactions
 
 
 class UpgradeOperation:
     """represent the work to be done during an upgrade"""
 
     def __init__(
         self,
         ui,
         new_requirements,
         current_requirements,
         upgrade_actions,
         removed_actions,
         revlogs_to_process,
         backup_store,
     ):
         self.ui = ui
         self.new_requirements = new_requirements
         self.current_requirements = current_requirements
         # list of upgrade actions the operation will perform
         self.upgrade_actions = upgrade_actions
         self.removed_actions = removed_actions
         self.revlogs_to_process = revlogs_to_process
         # requirements which will be added by the operation
         self._added_requirements = (
             self.new_requirements - self.current_requirements
         )
         # requirements which will be removed by the operation
         self._removed_requirements = (
             self.current_requirements - self.new_requirements
         )
         # requirements which will be preserved by the operation
         self._preserved_requirements = (
             self.current_requirements & self.new_requirements
         )
         # optimizations which are not used and it's recommended that they
         # should use them
         all_optimizations = findoptimizations(None)
         self.unused_optimizations = [
             i for i in all_optimizations if i not in self.upgrade_actions
         ]
 
         # delta reuse mode of this upgrade operation
         upgrade_actions_names = self.upgrade_actions_names
         self.delta_reuse_mode = revlog.revlog.DELTAREUSEALWAYS
         if b're-delta-all' in upgrade_actions_names:
             self.delta_reuse_mode = revlog.revlog.DELTAREUSENEVER
         elif b're-delta-parent' in upgrade_actions_names:
             self.delta_reuse_mode = revlog.revlog.DELTAREUSESAMEREVS
         elif b're-delta-multibase' in upgrade_actions_names:
             self.delta_reuse_mode = revlog.revlog.DELTAREUSESAMEREVS
         elif b're-delta-fulladd' in upgrade_actions_names:
             self.delta_reuse_mode = revlog.revlog.DELTAREUSEFULLADD
 
         # should this operation force re-delta of both parents
         self.force_re_delta_both_parents = (
             b're-delta-multibase' in upgrade_actions_names
         )
 
         # should this operation create a backup of the store
         self.backup_store = backup_store
 
     @property
     def upgrade_actions_names(self):
         return set([a.name for a in self.upgrade_actions])
 
     @property
     def requirements_only(self):
         # does the operation only touches repository requirement
         return (
             self.touches_requirements
             and not self.touches_filelogs
             and not self.touches_manifests
             and not self.touches_changelog
             and not self.touches_dirstate
         )
 
     @property
     def touches_filelogs(self):
         for a in self.upgrade_actions:
             # in optimisations, we re-process the revlogs again
             if a.type == OPTIMISATION:
                 return True
             elif a.touches_filelogs:
                 return True
         for a in self.removed_actions:
             if a.touches_filelogs:
                 return True
         return False
 
     @property
     def touches_manifests(self):
         for a in self.upgrade_actions:
             # in optimisations, we re-process the revlogs again
             if a.type == OPTIMISATION:
                 return True
             elif a.touches_manifests:
                 return True
         for a in self.removed_actions:
             if a.touches_manifests:
                 return True
         return False
 
     @property
     def touches_changelog(self):
         for a in self.upgrade_actions:
             # in optimisations, we re-process the revlogs again
             if a.type == OPTIMISATION:
                 return True
             elif a.touches_changelog:
                 return True
         for a in self.removed_actions:
             if a.touches_changelog:
                 return True
         return False
 
     @property
     def touches_requirements(self):
         for a in self.upgrade_actions:
             # optimisations are used to re-process revlogs and does not result
             # in a requirement being added or removed
             if a.type == OPTIMISATION:
                 pass
             elif a.touches_requirements:
                 return True
         for a in self.removed_actions:
             if a.touches_requirements:
                 return True
 
     @property
     def touches_dirstate(self):
         for a in self.upgrade_actions:
             # revlog optimisations do not affect the dirstate
             if a.type == OPTIMISATION:
                 pass
             elif a.touches_dirstate:
                 return True
         for a in self.removed_actions:
             if a.touches_dirstate:
                 return True
 
         return False
 
     def _write_labeled(self, l, label):
         """
         Utility function to aid writing of a list under one label
         """
         first = True
         for r in sorted(l):
             if not first:
                 self.ui.write(b', ')
             self.ui.write(r, label=label)
             first = False
 
     def print_requirements(self):
         self.ui.write(_(b'requirements\n'))
         self.ui.write(_(b'   preserved: '))
         self._write_labeled(
             self._preserved_requirements, "upgrade-repo.requirement.preserved"
         )
         self.ui.write((b'\n'))
         if self._removed_requirements:
             self.ui.write(_(b'   removed: '))
             self._write_labeled(
                 self._removed_requirements, "upgrade-repo.requirement.removed"
             )
             self.ui.write((b'\n'))
         if self._added_requirements:
             self.ui.write(_(b'   added: '))
             self._write_labeled(
                 self._added_requirements, "upgrade-repo.requirement.added"
             )
             self.ui.write((b'\n'))
         self.ui.write(b'\n')
 
     def print_optimisations(self):
         optimisations = [
             a for a in self.upgrade_actions if a.type == OPTIMISATION
         ]
         optimisations.sort(key=lambda a: a.name)
         if optimisations:
             self.ui.write(_(b'optimisations: '))
             self._write_labeled(
                 [a.name for a in optimisations],
                 "upgrade-repo.optimisation.performed",
             )
             self.ui.write(b'\n\n')
 
     def print_upgrade_actions(self):
         for a in self.upgrade_actions:
             self.ui.status(b'%s\n   %s\n\n' % (a.name, a.upgrademessage))
 
     def print_affected_revlogs(self):
         if not self.revlogs_to_process:
             self.ui.write((b'no revlogs to process\n'))
         else:
             self.ui.write((b'processed revlogs:\n'))
             for r in sorted(self.revlogs_to_process):
                 self.ui.write((b'  - %s\n' % r))
         self.ui.write((b'\n'))
 
     def print_unused_optimizations(self):
         for i in self.unused_optimizations:
             self.ui.status(_(b'%s\n   %s\n\n') % (i.name, i.description))
 
     def has_upgrade_action(self, name):
         """Check whether the upgrade operation will perform this action"""
         return name in self._upgrade_actions_names
 
     def print_post_op_messages(self):
         """print post upgrade operation warning messages"""
         for a in self.upgrade_actions:
             if a.postupgrademessage is not None:
                 self.ui.warn(b'%s\n' % a.postupgrademessage)
         for a in self.removed_actions:
             if a.postdowngrademessage is not None:
                 self.ui.warn(b'%s\n' % a.postdowngrademessage)
 
 
 ###  Code checking if a repository can got through the upgrade process at all. #
 
 
 def requiredsourcerequirements(repo):
     """Obtain requirements required to be present to upgrade a repo.
 
     An upgrade will not be allowed if the repository doesn't have the
     requirements returned by this function.
     """
     return {
         # Introduced in Mercurial 0.9.2.
         requirements.STORE_REQUIREMENT,
     }
 
 
 def blocksourcerequirements(repo):
     """Obtain requirements that will prevent an upgrade from occurring.
 
     An upgrade cannot be performed if the source repository contains a
     requirements in the returned set.
     """
     return {
         # The upgrade code does not yet support these experimental features.
         # This is an artificial limitation.
         requirements.TREEMANIFEST_REQUIREMENT,
         # This was a precursor to generaldelta and was never enabled by default.
         # It should (hopefully) not exist in the wild.
         b'parentdelta',
     }
 
 
 def check_revlog_version(reqs):
     """Check that the requirements contain at least one Revlog version"""
     all_revlogs = {
         requirements.REVLOGV1_REQUIREMENT,
         requirements.REVLOGV2_REQUIREMENT,
     }
     if not all_revlogs.intersection(reqs):
         msg = _(b'cannot upgrade repository; missing a revlog version')
         raise error.Abort(msg)
 
 
 def check_source_requirements(repo):
     """Ensure that no existing requirements prevent the repository upgrade"""
 
     check_revlog_version(repo.requirements)
     required = requiredsourcerequirements(repo)
     missingreqs = required - repo.requirements
     if missingreqs:
         msg = _(b'cannot upgrade repository; requirement missing: %s')
         missingreqs = b', '.join(sorted(missingreqs))
         raise error.Abort(msg % missingreqs)
 
     blocking = blocksourcerequirements(repo)
     blockingreqs = blocking & repo.requirements
     if blockingreqs:
         m = _(b'cannot upgrade repository; unsupported source requirement: %s')
         blockingreqs = b', '.join(sorted(blockingreqs))
         raise error.Abort(m % blockingreqs)
     # Upgrade should operate on the actual store, not the shared link.
 
     bad_share = (
         requirements.SHARED_REQUIREMENT in repo.requirements
         and requirements.SHARESAFE_REQUIREMENT not in repo.requirements
     )
     if bad_share:
         m = _(b'cannot upgrade repository; share repository without share-safe')
         h = _(b'check :hg:`help config.format.use-share-safe`')
         raise error.Abort(m, hint=h)
 
 
 ### Verify the validity of the planned requirement changes ####################
 
 
 def supportremovedrequirements(repo):
     """Obtain requirements that can be removed during an upgrade.
 
     If an upgrade were to create a repository that dropped a requirement,
     the dropped requirement must appear in the returned set for the upgrade
     to be allowed.
     """
     supported = {
         requirements.SPARSEREVLOG_REQUIREMENT,
         requirements.COPIESSDC_REQUIREMENT,
         requirements.NODEMAP_REQUIREMENT,
         requirements.SHARESAFE_REQUIREMENT,
         requirements.REVLOGV2_REQUIREMENT,
         requirements.CHANGELOGV2_REQUIREMENT,
         requirements.REVLOGV1_REQUIREMENT,
         requirements.DIRSTATE_TRACKED_HINT_V1,
         requirements.DIRSTATE_V2_REQUIREMENT,
     }
     for name in compression.compengines:
         engine = compression.compengines[name]
         if engine.available() and engine.revlogheader():
             supported.add(b'exp-compression-%s' % name)
             if engine.name() == b'zstd':
                 supported.add(b'revlog-compression-zstd')
     return supported
 
 
 def supporteddestrequirements(repo):
     """Obtain requirements that upgrade supports in the destination.
 
     If the result of the upgrade would have requirements not in this set,
     the upgrade is disallowed.
 
     Extensions should monkeypatch this to add their custom requirements.
     """
     supported = {
         requirements.CHANGELOGV2_REQUIREMENT,
         requirements.COPIESSDC_REQUIREMENT,
         requirements.DIRSTATE_TRACKED_HINT_V1,
         requirements.DIRSTATE_V2_REQUIREMENT,
         requirements.DOTENCODE_REQUIREMENT,
         requirements.FNCACHE_REQUIREMENT,
         requirements.GENERALDELTA_REQUIREMENT,
         requirements.NODEMAP_REQUIREMENT,
         requirements.REVLOGV1_REQUIREMENT,  # allowed in case of downgrade
         requirements.REVLOGV2_REQUIREMENT,
         requirements.SHARED_REQUIREMENT,
         requirements.SHARESAFE_REQUIREMENT,
         requirements.SPARSEREVLOG_REQUIREMENT,
         requirements.STORE_REQUIREMENT,
         requirements.NARROW_REQUIREMENT,
     }
     for name in compression.compengines:
         engine = compression.compengines[name]
         if engine.available() and engine.revlogheader():
             supported.add(b'exp-compression-%s' % name)
             if engine.name() == b'zstd':
                 supported.add(b'revlog-compression-zstd')
     return supported
 
 
 def allowednewrequirements(repo):
     """Obtain requirements that can be added to a repository during upgrade.
 
     This is used to disallow proposed requirements from being added when
     they weren't present before.
 
     We use a list of allowed requirement additions instead of a list of known
     bad additions because the whitelist approach is safer and will prevent
     future, unknown requirements from accidentally being added.
     """
     supported = {
         requirements.DOTENCODE_REQUIREMENT,
         requirements.FNCACHE_REQUIREMENT,
         requirements.GENERALDELTA_REQUIREMENT,
         requirements.SPARSEREVLOG_REQUIREMENT,
         requirements.COPIESSDC_REQUIREMENT,
         requirements.NODEMAP_REQUIREMENT,
         requirements.SHARESAFE_REQUIREMENT,
         requirements.REVLOGV1_REQUIREMENT,
         requirements.REVLOGV2_REQUIREMENT,
         requirements.CHANGELOGV2_REQUIREMENT,
         requirements.DIRSTATE_TRACKED_HINT_V1,
         requirements.DIRSTATE_V2_REQUIREMENT,
     }
     for name in compression.compengines:
         engine = compression.compengines[name]
         if engine.available() and engine.revlogheader():
             supported.add(b'exp-compression-%s' % name)
             if engine.name() == b'zstd':
                 supported.add(b'revlog-compression-zstd')
     return supported
 
 
 def check_requirements_changes(repo, new_reqs):
     old_reqs = repo.requirements
     check_revlog_version(repo.requirements)
     support_removal = supportremovedrequirements(repo)
     no_remove_reqs = old_reqs - new_reqs - support_removal
     if no_remove_reqs:
         msg = _(b'cannot upgrade repository; requirement would be removed: %s')
         no_remove_reqs = b', '.join(sorted(no_remove_reqs))
         raise error.Abort(msg % no_remove_reqs)
 
     support_addition = allowednewrequirements(repo)
     no_add_reqs = new_reqs - old_reqs - support_addition
     if no_add_reqs:
         m = _(b'cannot upgrade repository; do not support adding requirement: ')
         no_add_reqs = b', '.join(sorted(no_add_reqs))
         raise error.Abort(m + no_add_reqs)
 
     supported = supporteddestrequirements(repo)
     unsupported_reqs = new_reqs - supported
     if unsupported_reqs:
         msg = _(
             b'cannot upgrade repository; do not support destination '
             b'requirement: %s'
         )
         unsupported_reqs = b', '.join(sorted(unsupported_reqs))
         raise error.Abort(msg % unsupported_reqs)

tests/test-copies-chain-merge.t

@@ -1,3850 +1,3846 b''
 #testcases filelog compatibility changeset sidedata upgraded upgraded-parallel pull push pull-upgrade push-upgrade
 
 =====================================================
 Test Copy tracing for chain of copies involving merge
 =====================================================
 
 This test files covers copies/rename case for a chains of commit where merges
 are involved. It cheks we do not have unwanted update of behavior and that the
 different options to retrieve copies behave correctly.
 
 
 Setup
 =====
 
 use git diff to see rename
 
   $ cat << EOF >> ./no-linkrev
   > #!$PYTHON
   > # filter out linkrev part of the debugindex command
   > import sys
   > for line in sys.stdin:
   >     if " linkrev " in line:
   >         print(line.rstrip())
   >     else:
   >         l = "%s       *%s" % (line[:6], line[14:].rstrip())
   >         print(l)
   > EOF
 
   $ cat << EOF >> $HGRCPATH
   > [diff]
   > git=yes
   > [command-templates]
   > log={desc}\n
   > EOF
 
 #if compatibility
   $ cat >> $HGRCPATH << EOF
   > [experimental]
   > copies.read-from = compatibility
   > EOF
 #endif
 
 #if changeset
   $ cat >> $HGRCPATH << EOF
   > [experimental]
   > copies.read-from = changeset-only
   > copies.write-to = changeset-only
   > EOF
 #endif
 
 #if sidedata
   $ cat >> $HGRCPATH << EOF
   > [format]
   > exp-use-copies-side-data-changeset = yes
   > EOF
 #endif
 
 #if pull
   $ cat >> $HGRCPATH << EOF
   > [format]
   > exp-use-copies-side-data-changeset = yes
   > EOF
 #endif
 
 #if push
   $ cat >> $HGRCPATH << EOF
   > [format]
   > exp-use-copies-side-data-changeset = yes
   > EOF
 #endif
 
 #if pull-upgrade
   $ cat >> $HGRCPATH << EOF
   > [format]
   > exp-use-copies-side-data-changeset = no
   > [experimental]
   > changegroup4 = yes
   > EOF
 #endif
 
 #if push-upgrade
   $ cat >> $HGRCPATH << EOF
   > [format]
   > exp-use-copies-side-data-changeset = no
   > [experimental]
   > changegroup4 = yes
   > EOF
 #endif
 
   $ cat > same-content.txt << EOF
   > Here is some content that will be the same accros multiple file.
   > 
   > This is done on purpose so that we end up in some merge situation, were the
   > resulting content is the same as in the parent(s), but a new filenodes still
   > need to be created to record some file history information (especially
   > about copies).
   > EOF
 
   $ hg init repo-chain
   $ cd repo-chain
 
 Add some linear rename initialy
 
   $ cp ../same-content.txt a
   $ cp ../same-content.txt b
   $ cp ../same-content.txt h
   $ echo "original content for P" > p
   $ echo "original content for Q" > q
   $ echo "original content for R" > r
   $ hg ci -Am 'i-0 initial commit: a b h p q r'
   adding a
   adding b
   adding h
   adding p
   adding q
   adding r
   $ hg mv a c
   $ hg mv p s
   $ hg ci -Am 'i-1: a -move-> c, p -move-> s'
   $ hg mv c d
   $ hg mv s t
   $ hg ci -Am 'i-2: c -move-> d, s -move-> t'
   $ hg log -G
   @  i-2: c -move-> d, s -move-> t
   |
   o  i-1: a -move-> c, p -move-> s
   |
   o  i-0 initial commit: a b h p q r
   
 
 And having another branch with renames on the other side
 
   $ hg mv d e
   $ hg ci -Am 'a-1: d -move-> e'
   $ hg mv e f
   $ hg ci -Am 'a-2: e -move-> f'
   $ hg log -G --rev '::.'
   @  a-2: e -move-> f
   |
   o  a-1: d -move-> e
   |
   o  i-2: c -move-> d, s -move-> t
   |
   o  i-1: a -move-> c, p -move-> s
   |
   o  i-0 initial commit: a b h p q r
   
 
 Have a branching with nothing on one side
 
   $ hg up 'desc("i-2")'
   1 files updated, 0 files merged, 1 files removed, 0 files unresolved
   $ echo foo > b
   $ hg ci -m 'b-1: b update'
   created new head
   $ hg log -G --rev '::.'
   @  b-1: b update
   |
   o  i-2: c -move-> d, s -move-> t
   |
   o  i-1: a -move-> c, p -move-> s
   |
   o  i-0 initial commit: a b h p q r
   
 
 Create a branch that delete a file previous renamed
 
   $ hg up 'desc("i-2")'
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
   $ hg rm d
   $ hg ci -m 'c-1 delete d'
   created new head
   $ hg log -G --rev '::.'
   @  c-1 delete d
   |
   o  i-2: c -move-> d, s -move-> t
   |
   o  i-1: a -move-> c, p -move-> s
   |
   o  i-0 initial commit: a b h p q r
   
 
 Create a branch that delete a file previous renamed and recreate it
 
   $ hg up 'desc("i-2")'
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
   $ hg rm d
   $ hg ci -m 'd-1 delete d'
   created new head
   $ echo bar > d
   $ hg add d
   $ hg ci -m 'd-2 re-add d'
   $ hg log -G --rev '::.'
   @  d-2 re-add d
   |
   o  d-1 delete d
   |
   o  i-2: c -move-> d, s -move-> t
   |
   o  i-1: a -move-> c, p -move-> s
   |
   o  i-0 initial commit: a b h p q r
   
 
 Having another branch renaming a different file to the same filename as another
 
   $ hg up 'desc("i-2")'
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
   $ hg mv b g
   $ hg ci -m 'e-1 b -move-> g'
   created new head
   $ hg mv g f
   $ hg ci -m 'e-2 g -move-> f'
   $ hg log -G --rev '::.'
   @  e-2 g -move-> f
   |
   o  e-1 b -move-> g
   |
   o  i-2: c -move-> d, s -move-> t
   |
   o  i-1: a -move-> c, p -move-> s
   |
   o  i-0 initial commit: a b h p q r
   
   $ hg up -q null
 
 Having a branch similar to the 'a' one, but moving the 'p' file around.
 
   $ hg up 'desc("i-2")'
   6 files updated, 0 files merged, 0 files removed, 0 files unresolved
   $ hg mv t u
   $ hg ci -Am 'p-1: t -move-> u'
   created new head
   $ hg mv u v
   $ hg ci -Am 'p-2: u -move-> v'
   $ hg log -G --rev '::.'
   @  p-2: u -move-> v
   |
   o  p-1: t -move-> u
   |
   o  i-2: c -move-> d, s -move-> t
   |
   o  i-1: a -move-> c, p -move-> s
   |
   o  i-0 initial commit: a b h p q r
   
   $ hg up -q null
 
 Having another branch renaming a different file to the same filename as another
 
   $ hg up 'desc("i-2")'
   6 files updated, 0 files merged, 0 files removed, 0 files unresolved
   $ hg mv r w
   $ hg ci -m 'q-1 r -move-> w'
   created new head
   $ hg mv w v
   $ hg ci -m 'q-2 w -move-> v'
   $ hg log -G --rev '::.'
   @  q-2 w -move-> v
   |
   o  q-1 r -move-> w
   |
   o  i-2: c -move-> d, s -move-> t
   |
   o  i-1: a -move-> c, p -move-> s
   |
   o  i-0 initial commit: a b h p q r
   
   $ hg up -q null
 
 Setup all merge
 ===============
 
 This is done beforehand to validate that the upgrade process creates valid copy
 information.
 
 merging with unrelated change does not interfere with the renames
 ---------------------------------------------------------------
 
 - rename on one side
 - unrelated change on the other side
 
   $ case_desc="simple merge - A side: multiple renames, B side: unrelated update"
 
   $ hg up 'desc("b-1")'
   6 files updated, 0 files merged, 0 files removed, 0 files unresolved
   $ hg merge 'desc("a-2")'
   1 files updated, 0 files merged, 1 files removed, 0 files unresolved
   (branch merge, don't forget to commit)
   $ hg ci -m "mBAm-0 $case_desc - one way"
   $ hg up 'desc("a-2")'
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
   $ hg merge 'desc("b-1")'
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
   (branch merge, don't forget to commit)
   $ hg ci -m "mABm-0 $case_desc - the other way"
   created new head
   $ hg log -G --rev '::(desc("mABm")+desc("mBAm"))'
   @    mABm-0 simple merge - A side: multiple renames, B side: unrelated update - the other way
   |\
   +---o  mBAm-0 simple merge - A side: multiple renames, B side: unrelated update - one way
   | |/
   | o  b-1: b update
   | |
   o |  a-2: e -move-> f
   | |
   o |  a-1: d -move-> e
   |/
   o  i-2: c -move-> d, s -move-> t
   |
   o  i-1: a -move-> c, p -move-> s
   |
   o  i-0 initial commit: a b h p q r
   
 
 
 merging with the side having a delete
 -------------------------------------
 
 case summary:
 - one with change to an unrelated file
 - one deleting the change
 and recreate an unrelated file after the merge
 
   $ case_desc="simple merge - C side: delete a file with copies history , B side: unrelated update"
 
   $ hg up 'desc("b-1")'
   1 files updated, 0 files merged, 1 files removed, 0 files unresolved
   $ hg merge 'desc("c-1")'
   0 files updated, 0 files merged, 1 files removed, 0 files unresolved
   (branch merge, don't forget to commit)
   $ hg ci -m "mBCm-0 $case_desc - one way"
   $ echo bar > d
   $ hg add d
   $ hg ci -m 'mBCm-1 re-add d'
   $ hg up 'desc("c-1")'
   1 files updated, 0 files merged, 1 files removed, 0 files unresolved
   $ hg merge 'desc("b-1")'
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
   (branch merge, don't forget to commit)
   $ hg ci -m "mCBm-0 $case_desc - the other way"
   created new head
   $ echo bar > d
   $ hg add d
   $ hg ci -m 'mCBm-1 re-add d'
   $ hg log -G --rev '::(desc("mCBm")+desc("mBCm"))'
   @  mCBm-1 re-add d
   |
   o    mCBm-0 simple merge - C side: delete a file with copies history , B side: unrelated update - the other way
   |\
   | | o  mBCm-1 re-add d
   | | |
   +---o  mBCm-0 simple merge - C side: delete a file with copies history , B side: unrelated update - one way
   | |/
   | o  c-1 delete d
   | |
   o |  b-1: b update
   |/
   o  i-2: c -move-> d, s -move-> t
   |
   o  i-1: a -move-> c, p -move-> s
   |
   o  i-0 initial commit: a b h p q r
   
 
 Comparing with a merge re-adding the file afterward
 ---------------------------------------------------
 
 Merge:
 - one with change to an unrelated file
 - one deleting and recreating the change
 
   $ case_desc="simple merge - B side: unrelated update, D side: delete and recreate a file (with different content)"
 
   $ hg up 'desc("b-1")'
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
   $ hg merge 'desc("d-2")'
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
   (branch merge, don't forget to commit)
   $ hg ci -m "mBDm-0 $case_desc - one way"
   $ hg up 'desc("d-2")'
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
   $ hg merge 'desc("b-1")'
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
   (branch merge, don't forget to commit)
   $ hg ci -m "mDBm-0 $case_desc - the other way"
   created new head
   $ hg log -G --rev '::(desc("mDBm")+desc("mBDm"))'
   @    mDBm-0 simple merge - B side: unrelated update, D side: delete and recreate a file (with different content) - the other way
   |\
   +---o  mBDm-0 simple merge - B side: unrelated update, D side: delete and recreate a file (with different content) - one way
   | |/
   | o  d-2 re-add d
   | |
   | o  d-1 delete d
   | |
   o |  b-1: b update
   |/
   o  i-2: c -move-> d, s -move-> t
   |
   o  i-1: a -move-> c, p -move-> s
   |
   o  i-0 initial commit: a b h p q r
   
 
 
 Comparing with a merge with colliding rename
 --------------------------------------------
 
 Subcase: new copy information on both side
 ``````````````````````````````````````````
 
 - the "e-" branch renaming b to f (through 'g')
 - the "a-" branch renaming d to f (through e)
 
   $ case_desc="merge with copies info on both side - A side: rename d to f, E side: b to f, (same content for f)"
 
   $ hg up 'desc("a-2")'
   2 files updated, 0 files merged, 1 files removed, 0 files unresolved
   $ hg merge 'desc("e-2")'
   1 files updated, 0 files merged, 1 files removed, 0 files unresolved (no-changeset !)
   0 files updated, 0 files merged, 1 files removed, 0 files unresolved (changeset !)
   (branch merge, don't forget to commit)
   $ hg ci -m "mAEm-0 $case_desc - one way"
   $ hg up 'desc("e-2")'
   2 files updated, 0 files merged, 0 files removed, 0 files unresolved (no-changeset !)
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved (changeset !)
   $ hg merge 'desc("a-2")'
   1 files updated, 0 files merged, 1 files removed, 0 files unresolved (no-changeset !)
   0 files updated, 0 files merged, 1 files removed, 0 files unresolved (changeset !)
   (branch merge, don't forget to commit)
   $ hg ci -m "mEAm-0 $case_desc - the other way"
   created new head
   $ hg log -G --rev '::(desc("mAEm")+desc("mEAm"))'
   @    mEAm-0 merge with copies info on both side - A side: rename d to f, E side: b to f, (same content for f) - the other way
   |\
   +---o  mAEm-0 merge with copies info on both side - A side: rename d to f, E side: b to f, (same content for f) - one way
   | |/
   | o  e-2 g -move-> f
   | |
   | o  e-1 b -move-> g
   | |
   o |  a-2: e -move-> f
   | |
   o |  a-1: d -move-> e
   |/
   o  i-2: c -move-> d, s -move-> t
   |
   o  i-1: a -move-> c, p -move-> s
   |
   o  i-0 initial commit: a b h p q r
   
 
 Subcase: new copy information on both side with an actual merge happening
 `````````````````````````````````````````````````````````````````````````
 
 - the "p-" branch renaming 't' to 'v' (through 'u')
 - the "q-" branch renaming 'r' to 'v' (through 'w')
 
   $ case_desc="merge with copies info on both side - P side: rename t to v, Q side: r to v, (different content)"
 
   $ hg up 'desc("p-2")'
   3 files updated, 0 files merged, 2 files removed, 0 files unresolved
   $ hg merge 'desc("q-2")' --tool ':union'
   merging v
   0 files updated, 1 files merged, 1 files removed, 0 files unresolved
   (branch merge, don't forget to commit)
   $ hg ci -m "mPQm-0 $case_desc - one way"
   $ hg up 'desc("q-2")'
   2 files updated, 0 files merged, 0 files removed, 0 files unresolved
   $ hg merge 'desc("p-2")' --tool ':union'
   merging v
   0 files updated, 1 files merged, 1 files removed, 0 files unresolved
   (branch merge, don't forget to commit)
   $ hg ci -m "mQPm-0 $case_desc - the other way"
   created new head
   $ hg log -G --rev '::(desc("mAEm")+desc("mEAm"))'
   o    mEAm-0 merge with copies info on both side - A side: rename d to f, E side: b to f, (same content for f) - the other way
   |\
   +---o  mAEm-0 merge with copies info on both side - A side: rename d to f, E side: b to f, (same content for f) - one way
   | |/
   | o  e-2 g -move-> f
   | |
   | o  e-1 b -move-> g
   | |
   o |  a-2: e -move-> f
   | |
   o |  a-1: d -move-> e
   |/
   o  i-2: c -move-> d, s -move-> t
   |
   o  i-1: a -move-> c, p -move-> s
   |
   o  i-0 initial commit: a b h p q r
   
 
 Subcase: existing copy information overwritten on one branch
 ````````````````````````````````````````````````````````````
 
 Merge:
 - one with change to an unrelated file (b)
 - one overwriting a file (d) with a rename (from h to i to d)
 
   $ case_desc="simple merge - B side: unrelated change, F side: overwrite d with a copy (from h->i->d)"
 
   $ hg up 'desc("i-2")'
   2 files updated, 0 files merged, 1 files removed, 0 files unresolved
   $ hg mv h i
   $ hg commit -m "f-1: rename h -> i"
   created new head
   $ hg mv --force i d
   $ hg commit -m "f-2: rename i -> d"
   $ hg debugindex d | "$PYTHON" ../no-linkrev
      rev linkrev nodeid       p1           p2
        0       * d8252ab2e760 000000000000 000000000000 (no-changeset !)
        0       * ae258f702dfe 000000000000 000000000000 (changeset !)
        1       * b004912a8510 000000000000 000000000000
        2       * 7b79e2fe0c89 000000000000 000000000000 (no-changeset !)
   $ hg up 'desc("b-1")'
   3 files updated, 0 files merged, 0 files removed, 0 files unresolved (no-changeset !)
   2 files updated, 0 files merged, 0 files removed, 0 files unresolved (changeset !)
   $ hg merge 'desc("f-2")'
   1 files updated, 0 files merged, 1 files removed, 0 files unresolved (no-changeset !)
   0 files updated, 0 files merged, 1 files removed, 0 files unresolved (changeset !)
   (branch merge, don't forget to commit)
   $ hg ci -m "mBFm-0 $case_desc - one way"
   $ hg up 'desc("f-2")'
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
   $ hg merge 'desc("b-1")'
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
   (branch merge, don't forget to commit)
   $ hg ci -m "mFBm-0 $case_desc - the other way"
   created new head
   $ hg up null --quiet
   $ hg log -G --rev '::(desc("mBFm")+desc("mFBm"))'
   o    mFBm-0 simple merge - B side: unrelated change, F side: overwrite d with a copy (from h->i->d) - the other way
   |\
   +---o  mBFm-0 simple merge - B side: unrelated change, F side: overwrite d with a copy (from h->i->d) - one way
   | |/
   | o  f-2: rename i -> d
   | |
   | o  f-1: rename h -> i
   | |
   o |  b-1: b update
   |/
   o  i-2: c -move-> d, s -move-> t
   |
   o  i-1: a -move-> c, p -move-> s
   |
   o  i-0 initial commit: a b h p q r
   
 
 Subcase: existing copy information overwritten on one branch, with different content)
 `````````````````````````````````````````````````````````````````````````````````````
 
 Merge:
 - one with change to an unrelated file (b)
 - one overwriting a file (t) with a rename (from r to x to t), v content is not the same as on the other branch
 
   $ case_desc="simple merge - B side: unrelated change, R side: overwrite d with a copy (from r->x->t) different content"
 
   $ hg up 'desc("i-2")'
   6 files updated, 0 files merged, 0 files removed, 0 files unresolved
   $ hg mv r x
   $ hg commit -m "r-1: rename r -> x"
   created new head
   $ hg mv --force x t
   $ hg commit -m "r-2: rename t -> x"
   $ hg debugindex t | "$PYTHON" ../no-linkrev
      rev linkrev nodeid       p1           p2
        0       * d74efbf65309 000000000000 000000000000 (no-changeset !)
        1       * 02a930b9d7ad 000000000000 000000000000 (no-changeset !)
        0       * 5aed6a8dbff0 000000000000 000000000000 (changeset !)
        1       * a38b2fa17021 000000000000 000000000000 (changeset !)
   $ hg up 'desc("b-1")'
   3 files updated, 0 files merged, 0 files removed, 0 files unresolved
   $ hg merge 'desc("r-2")'
   1 files updated, 0 files merged, 1 files removed, 0 files unresolved
   (branch merge, don't forget to commit)
   $ hg ci -m "mBRm-0 $case_desc - one way"
   $ hg up 'desc("r-2")'
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
   $ hg merge 'desc("b-1")'
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
   (branch merge, don't forget to commit)
   $ hg ci -m "mRBm-0 $case_desc - the other way"
   created new head
   $ hg up null --quiet
   $ hg log -G --rev '::(desc("mBRm")+desc("mRBm"))'
   o    mRBm-0 simple merge - B side: unrelated change, R side: overwrite d with a copy (from r->x->t) different content - the other way
   |\
   +---o  mBRm-0 simple merge - B side: unrelated change, R side: overwrite d with a copy (from r->x->t) different content - one way
   | |/
   | o  r-2: rename t -> x
   | |
   | o  r-1: rename r -> x
   | |
   o |  b-1: b update
   |/
   o  i-2: c -move-> d, s -move-> t
   |
   o  i-1: a -move-> c, p -move-> s
   |
   o  i-0 initial commit: a b h p q r
   
 
 
 Subcase: reset of the copy history on one side
 ``````````````````````````````````````````````
 
 Merge:
 - one with change to a file
 - one deleting and recreating the file
 
 Unlike in the 'BD/DB' cases, an actual merge happened here. So we should
 consider history and rename on both branch of the merge.
 
   $ case_desc="actual content merge, copies on one side - D side: delete and re-add (different content), G side: update content"
 
   $ hg up 'desc("i-2")'
   6 files updated, 0 files merged, 0 files removed, 0 files unresolved
   $ echo "some update" >> d
   $ hg commit -m "g-1: update d"
   created new head
   $ hg up 'desc("d-2")'
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
   $ hg merge 'desc("g-1")' --tool :union
   merging d
   0 files updated, 1 files merged, 0 files removed, 0 files unresolved
   (branch merge, don't forget to commit)
   $ hg ci -m "mDGm-0 $case_desc - one way"
   $ hg up 'desc("g-1")'
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
   $ hg merge 'desc("d-2")' --tool :union
   merging d
   0 files updated, 1 files merged, 0 files removed, 0 files unresolved
   (branch merge, don't forget to commit)
   $ hg ci -m "mGDm-0 $case_desc - the other way"
   created new head
   $ hg log -G --rev '::(desc("mDGm")+desc("mGDm"))'
   @    mGDm-0 actual content merge, copies on one side - D side: delete and re-add (different content), G side: update content - the other way
   |\
   +---o  mDGm-0 actual content merge, copies on one side - D side: delete and re-add (different content), G side: update content - one way
   | |/
   | o  g-1: update d
   | |
   o |  d-2 re-add d
   | |
   o |  d-1 delete d
   |/
   o  i-2: c -move-> d, s -move-> t
   |
   o  i-1: a -move-> c, p -move-> s
   |
   o  i-0 initial commit: a b h p q r
   
 
 Subcase: merging a change to a file with a "copy overwrite" to that file from another branch
 ````````````````````````````````````````````````````````````````````````````````````````````
 
 Merge:
 - one with change to a file (d)
 - one overwriting that file with a rename (from h to i, to d)
 
 This case is similar to BF/FB, but an actual merge happens, so both side of the
 history are relevant.
 
 Note:
 | In this case, the merge get conflicting information since on one side we have
 | "a -> c -> d". and one the other one we have "h -> i -> d".
 |
 | The current code arbitrarily pick one side
 
   $ case_desc="merge - G side: content change, F side: copy overwrite, no content change"
 
   $ hg up 'desc("f-2")'
   1 files updated, 0 files merged, 1 files removed, 0 files unresolved
   $ hg merge 'desc("g-1")' --tool :union
   merging d (no-changeset !)
   0 files updated, 1 files merged, 0 files removed, 0 files unresolved (no-changeset !)
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved (changeset !)
   (branch merge, don't forget to commit)
   $ hg ci -m "mFGm-0 $case_desc - one way"
   created new head
   $ hg up 'desc("g-1")'
   2 files updated, 0 files merged, 0 files removed, 0 files unresolved (no-changeset !)
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved (changeset !)
   $ hg merge 'desc("f-2")' --tool :union
   merging d (no-changeset !)
   0 files updated, 1 files merged, 1 files removed, 0 files unresolved (no-changeset !)
   0 files updated, 0 files merged, 1 files removed, 0 files unresolved (changeset !)
   (branch merge, don't forget to commit)
   $ hg ci -m "mGFm-0 $case_desc - the other way"
   created new head
   $ hg log -G --rev '::(desc("mGFm")+desc("mFGm"))'
   @    mGFm-0 merge - G side: content change, F side: copy overwrite, no content change - the other way
   |\
   +---o  mFGm-0 merge - G side: content change, F side: copy overwrite, no content change - one way
   | |/
   | o  g-1: update d
   | |
   o |  f-2: rename i -> d
   | |
   o |  f-1: rename h -> i
   |/
   o  i-2: c -move-> d, s -move-> t
   |
   o  i-1: a -move-> c, p -move-> s
   |
   o  i-0 initial commit: a b h p q r
   
 
 
 Comparing with merging with a deletion (and keeping the file)
 -------------------------------------------------------------
 
 Merge:
 - one removing a file (d)
 - one updating that file
 - the merge keep the modified version of the file (canceling the delete)
 
 In this case, the file keep on living after the merge. So we should not drop its
 copy tracing chain.
 
   $ case_desc="merge updated/deleted - revive the file (updated content)"
 
   $ hg up 'desc("c-1")'
   1 files updated, 0 files merged, 1 files removed, 0 files unresolved
   $ hg merge 'desc("g-1")'
   file 'd' was deleted in local [working copy] but was modified in other [merge rev].
   You can use (c)hanged version, leave (d)eleted, or leave (u)nresolved.
   What do you want to do? u
   0 files updated, 0 files merged, 0 files removed, 1 files unresolved
   use 'hg resolve' to retry unresolved file merges or 'hg merge --abort' to abandon
   [1]
   $ hg resolve -t :other d
   (no more unresolved files)
   $ hg ci -m "mCGm-0 $case_desc - one way"
   created new head
 
   $ hg up 'desc("g-1")'
   0 files updated, 0 files merged, 0 files removed, 0 files unresolved
   $ hg merge 'desc("c-1")'
   file 'd' was deleted in other [merge rev] but was modified in local [working copy].
   You can use (c)hanged version, (d)elete, or leave (u)nresolved.
   What do you want to do? u
   0 files updated, 0 files merged, 0 files removed, 1 files unresolved
   use 'hg resolve' to retry unresolved file merges or 'hg merge --abort' to abandon
   [1]
   $ hg resolve -t :local d
   (no more unresolved files)
   $ hg ci -m "mGCm-0 $case_desc - the other way"
   created new head
 
   $ hg log -G --rev '::(desc("mCGm")+desc("mGCm"))'
   @    mGCm-0 merge updated/deleted - revive the file (updated content) - the other way
   |\
   +---o  mCGm-0 merge updated/deleted - revive the file (updated content) - one way
   | |/
   | o  g-1: update d
   | |
   o |  c-1 delete d
   |/
   o  i-2: c -move-> d, s -move-> t
   |
   o  i-1: a -move-> c, p -move-> s
   |
   o  i-0 initial commit: a b h p q r
   
 
 
 
 Comparing with merge restoring an untouched deleted file
 --------------------------------------------------------
 
 Merge:
 - one removing a file (d)
 - one leaving the file untouched
 - the merge actively restore the file to the same content.
 
 In this case, the file keep on living after the merge. So we should not drop its
 copy tracing chain.
 
   $ case_desc="merge explicitely revive deleted file - B side: unrelated change, C side: delete d (restored by merge)"
 
   $ hg up 'desc("c-1")'
   0 files updated, 0 files merged, 1 files removed, 0 files unresolved
   $ hg merge 'desc("b-1")'
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
   (branch merge, don't forget to commit)
   $ hg revert --rev 'desc("b-1")' d
   $ hg ci -m "mCB-revert-m-0 $case_desc - one way"
   created new head
 
   $ hg up 'desc("b-1")'
   0 files updated, 0 files merged, 0 files removed, 0 files unresolved
   $ hg merge 'desc("c-1")'
   0 files updated, 0 files merged, 1 files removed, 0 files unresolved
   (branch merge, don't forget to commit)
   $ hg revert --rev 'desc("b-1")' d
   $ hg ci -m "mBC-revert-m-0 $case_desc - the other way"
   created new head
 
   $ hg log -G --rev '::(desc("mCB-revert-m")+desc("mBC-revert-m"))'
   @    mBC-revert-m-0 merge explicitely revive deleted file - B side: unrelated change, C side: delete d (restored by merge) - the other way
   |\
   +---o  mCB-revert-m-0 merge explicitely revive deleted file - B side: unrelated change, C side: delete d (restored by merge) - one way
   | |/
   | o  c-1 delete d
   | |
   o |  b-1: b update
   |/
   o  i-2: c -move-> d, s -move-> t
   |
   o  i-1: a -move-> c, p -move-> s
   |
   o  i-0 initial commit: a b h p q r
   
 
 
   $ hg up null --quiet
 
 Merging a branch where a rename was deleted with a branch where the same file was renamed
 ------------------------------------------------------------------------------------------
 
 Create a "conflicting" merge where `d` get removed on one branch before its
 rename information actually conflict with the other branch.
 
 (the copy information from the branch that was not deleted should win).
 
   $ case_desc="simple merge - C side: d is the results of renames then deleted, H side: d is result of another rename (same content as the other branch)"
 
   $ hg up 'desc("i-0")'
   6 files updated, 0 files merged, 0 files removed, 0 files unresolved
   $ hg mv b d
   $ hg ci -m "h-1: b -(move)-> d"
   created new head
 
   $ hg up 'desc("c-1")'
   2 files updated, 0 files merged, 3 files removed, 0 files unresolved
   $ hg merge 'desc("h-1")'
   1 files updated, 0 files merged, 1 files removed, 0 files unresolved
   (branch merge, don't forget to commit)
   $ hg ci -m "mCH-delete-before-conflict-m-0 $case_desc - one way"
 
   $ hg up 'desc("h-1")'
   2 files updated, 0 files merged, 1 files removed, 0 files unresolved
   $ hg merge 'desc("c-1")'
   1 files updated, 0 files merged, 2 files removed, 0 files unresolved
   (branch merge, don't forget to commit)
   $ hg ci -m "mHC-delete-before-conflict-m-0 $case_desc - the other way"
   created new head
   $ hg log -G --rev '::(desc("mCH-delete-before-conflict-m")+desc("mHC-delete-before-conflict-m"))'
   @    mHC-delete-before-conflict-m-0 simple merge - C side: d is the results of renames then deleted, H side: d is result of another rename (same content as the other branch) - the other way
   |\
   +---o  mCH-delete-before-conflict-m-0 simple merge - C side: d is the results of renames then deleted, H side: d is result of another rename (same content as the other branch) - one way
   | |/
   | o  h-1: b -(move)-> d
   | |
   o |  c-1 delete d
   | |
   o |  i-2: c -move-> d, s -move-> t
   | |
   o |  i-1: a -move-> c, p -move-> s
   |/
   o  i-0 initial commit: a b h p q r
   
 
 Variant of previous with extra changes introduced by the merge
 --------------------------------------------------------------
 
 Multiple cases above explicitely test cases where content are the same on both side during merge. In this section we will introduce variants for theses cases where new change are introduced to these file content during the merges.
 
 
 Subcase: merge has same initial content on both side, but merge introduced a change
 ```````````````````````````````````````````````````````````````````````````````````
 
 Same as `mAEm` and `mEAm` but with extra change to the file before commiting
 
 - the "e-" branch renaming b to f (through 'g')
 - the "a-" branch renaming d to f (through e)
 
   $ case_desc="merge with file update and copies info on both side - A side: rename d to f, E side: b to f, (same content for f in parent)"
 
   $ hg up 'desc("a-2")'
   2 files updated, 0 files merged, 1 files removed, 0 files unresolved
   $ hg merge 'desc("e-2")'
   1 files updated, 0 files merged, 1 files removed, 0 files unresolved (no-changeset !)
   0 files updated, 0 files merged, 1 files removed, 0 files unresolved (changeset !)
   (branch merge, don't forget to commit)
   $ echo "content change for mAE-change-m" > f
   $ hg ci -m "mAE-change-m-0 $case_desc - one way"
   created new head
   $ hg up 'desc("e-2")'
   2 files updated, 0 files merged, 0 files removed, 0 files unresolved
   $ hg merge 'desc("a-2")'
   1 files updated, 0 files merged, 1 files removed, 0 files unresolved (no-changeset !)
   0 files updated, 0 files merged, 1 files removed, 0 files unresolved (changeset !)
   (branch merge, don't forget to commit)
   $ echo "content change for mEA-change-m" > f
   $ hg ci -m "mEA-change-m-0 $case_desc - the other way"
   created new head
   $ hg log -G --rev '::(desc("mAE-change-m")+desc("mEA-change-m"))'
   @    mEA-change-m-0 merge with file update and copies info on both side - A side: rename d to f, E side: b to f, (same content for f in parent) - the other way
   |\
   +---o  mAE-change-m-0 merge with file update and copies info on both side - A side: rename d to f, E side: b to f, (same content for f in parent) - one way
   | |/
   | o  e-2 g -move-> f
   | |
   | o  e-1 b -move-> g
   | |
   o |  a-2: e -move-> f
   | |
   o |  a-1: d -move-> e
   |/
   o  i-2: c -move-> d, s -move-> t
   |
   o  i-1: a -move-> c, p -move-> s
   |
   o  i-0 initial commit: a b h p q r
   
 
 Subcase: merge overwrite common copy information, but with extra change during the merge
 ````````````````````````````````````````````````````````````````````````````````````````
 
 Merge:
 - one with change to an unrelated file (b)
 - one overwriting a file (d) with a rename (from h to i to d)
 - the merge update f content
 
   $ case_desc="merge with extra change - B side: unrelated change, F side: overwrite d with a copy (from h->i->d)"
 
   $ hg up 'desc("f-2")'
   2 files updated, 0 files merged, 2 files removed, 0 files unresolved
 #if no-changeset
   $ hg debugindex d | "$PYTHON" ../no-linkrev
      rev linkrev nodeid       p1           p2
        0       * d8252ab2e760 000000000000 000000000000
        1       * b004912a8510 000000000000 000000000000
        2       * 7b79e2fe0c89 000000000000 000000000000
        3       * 17ec97e60577 d8252ab2e760 000000000000
        4       * 06dabf50734c b004912a8510 17ec97e60577
        5       * 19c0e3924691 17ec97e60577 b004912a8510
        6       * 89c873a01d97 7b79e2fe0c89 17ec97e60577
        7       * d55cb4e9ef57 000000000000 000000000000
 #else
   $ hg debugindex d | "$PYTHON" ../no-linkrev
      rev linkrev nodeid       p1           p2
        0       * ae258f702dfe 000000000000 000000000000
        1       * b004912a8510 000000000000 000000000000
        2       * 5cce88bf349f ae258f702dfe 000000000000
        3       * cc269dd788c8 b004912a8510 5cce88bf349f
        4       * 51c91a115080 5cce88bf349f b004912a8510
 #endif
   $ hg up 'desc("b-1")'
   3 files updated, 0 files merged, 0 files removed, 0 files unresolved (no-changeset !)
   2 files updated, 0 files merged, 0 files removed, 0 files unresolved (changeset !)
   $ hg merge 'desc("f-2")'
   1 files updated, 0 files merged, 1 files removed, 0 files unresolved (no-changeset !)
   0 files updated, 0 files merged, 1 files removed, 0 files unresolved (changeset !)
   (branch merge, don't forget to commit)
   $ echo "extra-change to (formelly h) during the merge" > d
   $ hg ci -m "mBF-change-m-0 $case_desc - one way"
   created new head
   $ hg manifest --rev . --debug | grep "  d"
   1c334238bd42ec85c6a0d83fd1b2a898a6a3215d 644   d (no-changeset !)
   cea2d99c0fde64672ef61953786fdff34f16e230 644   d (changeset !)
 
   $ hg up 'desc("f-2")'
   2 files updated, 0 files merged, 0 files removed, 0 files unresolved
   $ hg merge 'desc("b-1")'
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
   (branch merge, don't forget to commit)
   $ echo "extra-change to (formelly h) during the merge" > d
   $ hg ci -m "mFB-change-m-0 $case_desc - the other way"
   created new head
   $ hg manifest --rev . --debug | grep "  d"
   1c334238bd42ec85c6a0d83fd1b2a898a6a3215d 644   d (no-changeset !)
   cea2d99c0fde64672ef61953786fdff34f16e230 644   d (changeset !)
 #if no-changeset
   $ hg debugindex d | "$PYTHON" ../no-linkrev
      rev linkrev nodeid       p1           p2
        0       * d8252ab2e760 000000000000 000000000000
        1       * b004912a8510 000000000000 000000000000
        2       * 7b79e2fe0c89 000000000000 000000000000
        3       * 17ec97e60577 d8252ab2e760 000000000000
        4       * 06dabf50734c b004912a8510 17ec97e60577
        5       * 19c0e3924691 17ec97e60577 b004912a8510
        6       * 89c873a01d97 7b79e2fe0c89 17ec97e60577
        7       * d55cb4e9ef57 000000000000 000000000000
        8       * 1c334238bd42 7b79e2fe0c89 000000000000
 #else
   $ hg debugindex d | "$PYTHON" ../no-linkrev
      rev linkrev nodeid       p1           p2
        0       * ae258f702dfe 000000000000 000000000000
        1       * b004912a8510 000000000000 000000000000
        2       * 5cce88bf349f ae258f702dfe 000000000000
        3       * cc269dd788c8 b004912a8510 5cce88bf349f
        4       * 51c91a115080 5cce88bf349f b004912a8510
        5       * cea2d99c0fde ae258f702dfe 000000000000
 #endif
   $ hg log -G --rev '::(desc("mBF-change-m")+desc("mFB-change-m"))'
   @    mFB-change-m-0 merge with extra change - B side: unrelated change, F side: overwrite d with a copy (from h->i->d) - the other way
   |\
   +---o  mBF-change-m-0 merge with extra change - B side: unrelated change, F side: overwrite d with a copy (from h->i->d) - one way
   | |/
   | o  f-2: rename i -> d
   | |
   | o  f-1: rename h -> i
   | |
   o |  b-1: b update
   |/
   o  i-2: c -move-> d, s -move-> t
   |
   o  i-1: a -move-> c, p -move-> s
   |
   o  i-0 initial commit: a b h p q r
   
 
 Subcase: restoring and untouched deleted file, while touching it
 ````````````````````````````````````````````````````````````````
 
 Merge:
 - one removing a file (d)
 - one leaving the file untouched
 - the merge actively restore the file to the same content.
 
 In this case, the file keep on living after the merge. So we should not drop its
 copy tracing chain.
 
   $ case_desc="merge explicitely revive deleted file - B side: unrelated change, C side: delete d (restored by merge)"
 
   $ hg up 'desc("c-1")'
   2 files updated, 0 files merged, 1 files removed, 0 files unresolved
   $ hg merge 'desc("b-1")'
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
   (branch merge, don't forget to commit)
   $ hg revert --rev 'desc("b-1")' d
   $ echo "new content for d after the revert" > d
   $ hg ci -m "mCB-change-m-0 $case_desc - one way"
   created new head
   $ hg manifest --rev . --debug | grep "  d"
   e333780c17752a3b0dd15e3ad48aa4e5c745f621 644   d (no-changeset !)
   4b540a18ad699234b2b2aa18cb69555ac9c4b1df 644   d (changeset !)
 
   $ hg up 'desc("b-1")'
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
   $ hg merge 'desc("c-1")'
   0 files updated, 0 files merged, 1 files removed, 0 files unresolved
   (branch merge, don't forget to commit)
   $ hg revert --rev 'desc("b-1")' d
   $ echo "new content for d after the revert" > d
   $ hg ci -m "mBC-change-m-0 $case_desc - the other way"
   created new head
   $ hg manifest --rev . --debug | grep "  d"
   e333780c17752a3b0dd15e3ad48aa4e5c745f621 644   d (no-changeset !)
   4b540a18ad699234b2b2aa18cb69555ac9c4b1df 644   d (changeset !)
 
 
   $ hg up null --quiet
   $ hg log -G --rev '::(desc("mCB-change-m")+desc("mBC-change-m"))'
   o    mBC-change-m-0 merge explicitely revive deleted file - B side: unrelated change, C side: delete d (restored by merge) - the other way
   |\
   +---o  mCB-change-m-0 merge explicitely revive deleted file - B side: unrelated change, C side: delete d (restored by merge) - one way
   | |/
   | o  c-1 delete d
   | |
   o |  b-1: b update
   |/
   o  i-2: c -move-> d, s -move-> t
   |
   o  i-1: a -move-> c, p -move-> s
   |
   o  i-0 initial commit: a b h p q r
   
 
 Decision from previous merge are properly chained with later merge
 ------------------------------------------------------------------
 
 Subcase: chaining conflicting rename resolution
 ```````````````````````````````````````````````
 
 The "mAEm" and "mEAm" case create a rename tracking conflict on file 'f'. We
 add more change on the respective branch and merge again. These second merge
 does not involve the file 'f' and the arbitration done within "mAEm" and "mEA"
 about that file should stay unchanged.
 
 We also touch J during some of the merge to check for unrelated change to new file during merge.
 
   $ case_desc="chained merges (conflict -> simple) - same content everywhere"
 
 (extra unrelated changes)
 
   $ hg up 'desc("a-2")'
   6 files updated, 0 files merged, 0 files removed, 0 files unresolved
   $ echo j > unrelated-j
   $ hg add unrelated-j
   $ hg ci -m 'j-1: unrelated changes (based on the "a" series of changes)'
   created new head
 
   $ hg up 'desc("e-2")'
   2 files updated, 0 files merged, 2 files removed, 0 files unresolved (no-changeset !)
   1 files updated, 0 files merged, 2 files removed, 0 files unresolved (changeset !)
   $ echo k > unrelated-k
   $ hg add unrelated-k
   $ hg ci -m 'k-1: unrelated changes (based on "e" changes)'
   created new head
 
 (merge variant 1)
 
   $ hg up 'desc("mAEm")'
   1 files updated, 0 files merged, 2 files removed, 0 files unresolved (no-changeset !)
   0 files updated, 0 files merged, 2 files removed, 0 files unresolved (changeset !)
   $ hg merge 'desc("k-1")'
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
   (branch merge, don't forget to commit)
   $ hg ci -m "mAE,Km: $case_desc"
 
 (merge variant 2)
 
   $ hg up 'desc("k-1")'
   2 files updated, 0 files merged, 0 files removed, 0 files unresolved (no-changeset !)
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved (changeset !)
 
   $ hg merge 'desc("mAEm")'
   1 files updated, 0 files merged, 1 files removed, 0 files unresolved (no-changeset !)
   0 files updated, 0 files merged, 1 files removed, 0 files unresolved (changeset !)
   (branch merge, don't forget to commit)
   $ hg ci -m "mK,AEm: $case_desc"
   created new head
 
 (merge variant 3)
 
   $ hg up 'desc("mEAm")'
   0 files updated, 0 files merged, 1 files removed, 0 files unresolved
   $ hg merge 'desc("j-1")'
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
   (branch merge, don't forget to commit)
   $ echo jj > unrelated-j
   $ hg ci -m "mEA,Jm: $case_desc"
 
 (merge variant 4)
 
   $ hg up 'desc("j-1")'
   3 files updated, 0 files merged, 0 files removed, 0 files unresolved (no-changeset !)
   2 files updated, 0 files merged, 0 files removed, 0 files unresolved (changeset !)
   $ hg merge 'desc("mEAm")'
   1 files updated, 0 files merged, 1 files removed, 0 files unresolved (no-changeset !)
   0 files updated, 0 files merged, 1 files removed, 0 files unresolved (changeset !)
   (branch merge, don't forget to commit)
   $ echo jj > unrelated-j
   $ hg ci -m "mJ,EAm: $case_desc"
   created new head
 
 
   $ hg log -G --rev '::(desc("mAE,Km") + desc("mK,AEm") + desc("mEA,Jm") + desc("mJ,EAm"))'
   @    mJ,EAm: chained merges (conflict -> simple) - same content everywhere
   |\
   +---o  mEA,Jm: chained merges (conflict -> simple) - same content everywhere
   | |/
   | | o    mK,AEm: chained merges (conflict -> simple) - same content everywhere
   | | |\
   | | +---o  mAE,Km: chained merges (conflict -> simple) - same content everywhere
   | | | |/
   | | | o  k-1: unrelated changes (based on "e" changes)
   | | | |
   | o | |  j-1: unrelated changes (based on the "a" series of changes)
   | | | |
   o-----+  mEAm-0 merge with copies info on both side - A side: rename d to f, E side: b to f, (same content for f) - the other way
   |/ / /
   | o /  mAEm-0 merge with copies info on both side - A side: rename d to f, E side: b to f, (same content for f) - one way
   |/|/
   | o  e-2 g -move-> f
   | |
   | o  e-1 b -move-> g
   | |
   o |  a-2: e -move-> f
   | |
   o |  a-1: d -move-> e
   |/
   o  i-2: c -move-> d, s -move-> t
   |
   o  i-1: a -move-> c, p -move-> s
   |
   o  i-0 initial commit: a b h p q r
   
 
 Subcase: chaining conflicting rename resolution, with actual merging happening
 ``````````````````````````````````````````````````````````````````````````````
 
 The "mPQm" and "mQPm" case create a rename tracking conflict on file 't'. We
 add more change on the respective branch and merge again. These second merge
 does not involve the file 't' and the arbitration done within "mPQm" and "mQP"
 about that file should stay unchanged.
 
   $ case_desc="chained merges (conflict -> simple) - different content"
 
 (extra unrelated changes)
 
   $ hg up 'desc("p-2")'
   3 files updated, 0 files merged, 3 files removed, 0 files unresolved
   $ echo s > unrelated-s
   $ hg add unrelated-s
   $ hg ci -m 's-1: unrelated changes (based on the "p" series of changes)'
   created new head
 
   $ hg up 'desc("q-2")'
   2 files updated, 0 files merged, 2 files removed, 0 files unresolved
   $ echo t > unrelated-t
   $ hg add unrelated-t
   $ hg ci -m 't-1: unrelated changes (based on "q" changes)'
   created new head
 
 (merge variant 1)
 
   $ hg up 'desc("mPQm")'
   1 files updated, 0 files merged, 2 files removed, 0 files unresolved
   $ hg merge 'desc("t-1")'
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
   (branch merge, don't forget to commit)
   $ hg ci -m "mPQ,Tm: $case_desc"
 
 (merge variant 2)
 
   $ hg up 'desc("t-1")'
   2 files updated, 0 files merged, 0 files removed, 0 files unresolved
 
   $ hg merge 'desc("mPQm")'
   1 files updated, 0 files merged, 1 files removed, 0 files unresolved
   (branch merge, don't forget to commit)
   $ hg ci -m "mT,PQm: $case_desc"
   created new head
 
 (merge variant 3)
 
   $ hg up 'desc("mQPm")'
   1 files updated, 0 files merged, 1 files removed, 0 files unresolved
   $ hg merge 'desc("s-1")'
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
   (branch merge, don't forget to commit)
   $ hg ci -m "mQP,Sm: $case_desc"
 
 (merge variant 4)
 
   $ hg up 'desc("s-1")'
   2 files updated, 0 files merged, 0 files removed, 0 files unresolved
   $ hg merge 'desc("mQPm")'
   1 files updated, 0 files merged, 1 files removed, 0 files unresolved
   (branch merge, don't forget to commit)
   $ hg ci -m "mS,QPm: $case_desc"
   created new head
   $ hg up null --quiet
 
 
   $ hg log -G --rev '::(desc("mPQ,Tm") + desc("mT,PQm") + desc("mQP,Sm") + desc("mS,QPm"))'
   o    mS,QPm: chained merges (conflict -> simple) - different content
   |\
   +---o  mQP,Sm: chained merges (conflict -> simple) - different content
   | |/
   | | o    mT,PQm: chained merges (conflict -> simple) - different content
   | | |\
   | | +---o  mPQ,Tm: chained merges (conflict -> simple) - different content
   | | | |/
   | | | o  t-1: unrelated changes (based on "q" changes)
   | | | |
   | o | |  s-1: unrelated changes (based on the "p" series of changes)
   | | | |
   o-----+  mQPm-0 merge with copies info on both side - P side: rename t to v, Q side: r to v, (different content) - the other way
   |/ / /
   | o /  mPQm-0 merge with copies info on both side - P side: rename t to v, Q side: r to v, (different content) - one way
   |/|/
   | o  q-2 w -move-> v
   | |
   | o  q-1 r -move-> w
   | |
   o |  p-2: u -move-> v
   | |
   o |  p-1: t -move-> u
   |/
   o  i-2: c -move-> d, s -move-> t
   |
   o  i-1: a -move-> c, p -move-> s
   |
   o  i-0 initial commit: a b h p q r
   
 
 Subcase: chaining salvage information during a merge
 ````````````````````````````````````````````````````
 
 We add more change on the branch were the file was deleted. merging again
 should preserve the fact eh file was salvaged.
 
   $ case_desc="chained merges (salvaged -> simple) - same content (when the file exists)"
 
 (creating the change)
 
   $ hg up 'desc("c-1")'
   5 files updated, 0 files merged, 0 files removed, 0 files unresolved
   $ echo l > unrelated-l
   $ hg add unrelated-l
   $ hg ci -m 'l-1: unrelated changes (based on "c" changes)'
   created new head
 
 (Merge variant 1)
 
   $ hg up 'desc("mBC-revert-m")'
   2 files updated, 0 files merged, 1 files removed, 0 files unresolved
   $ hg merge 'desc("l-1")'
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
   (branch merge, don't forget to commit)
   $ hg ci -m "mBC+revert,Lm: $case_desc"
 
 (Merge variant 2)
 
   $ hg up 'desc("mCB-revert-m")'
   0 files updated, 0 files merged, 1 files removed, 0 files unresolved
   $ hg merge 'desc("l-1")'
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
   (branch merge, don't forget to commit)
   $ hg ci -m "mCB+revert,Lm: $case_desc"
 
 (Merge variant 3)
 
   $ hg up 'desc("l-1")'
   1 files updated, 0 files merged, 1 files removed, 0 files unresolved
 
   $ hg merge 'desc("mBC-revert-m")'
   2 files updated, 0 files merged, 0 files removed, 0 files unresolved
   (branch merge, don't forget to commit)
   $ hg ci -m "mL,BC+revertm: $case_desc"
   created new head
 
 (Merge variant 4)
 
   $ hg up 'desc("l-1")'
   1 files updated, 0 files merged, 1 files removed, 0 files unresolved
 
   $ hg merge 'desc("mCB-revert-m")'
   2 files updated, 0 files merged, 0 files removed, 0 files unresolved
   (branch merge, don't forget to commit)
   $ hg ci -m "mL,CB+revertm: $case_desc"
   created new head
 
   $ hg log -G --rev '::(desc("mBC+revert,Lm") + desc("mCB+revert,Lm") + desc("mL,BC+revertm") + desc("mL,CB+revertm"))'
   @    mL,CB+revertm: chained merges (salvaged -> simple) - same content (when the file exists)
   |\
   | | o  mL,BC+revertm: chained merges (salvaged -> simple) - same content (when the file exists)
   | |/|
   +-+---o  mCB+revert,Lm: chained merges (salvaged -> simple) - same content (when the file exists)
   | | |
   | +---o  mBC+revert,Lm: chained merges (salvaged -> simple) - same content (when the file exists)
   | | |/
   | o |  l-1: unrelated changes (based on "c" changes)
   | | |
   | | o  mBC-revert-m-0 merge explicitely revive deleted file - B side: unrelated change, C side: delete d (restored by merge) - the other way
   | |/|
   o---+  mCB-revert-m-0 merge explicitely revive deleted file - B side: unrelated change, C side: delete d (restored by merge) - one way
   |/ /
   o |  c-1 delete d
   | |
   | o  b-1: b update
   |/
   o  i-2: c -move-> d, s -move-> t
   |
   o  i-1: a -move-> c, p -move-> s
   |
   o  i-0 initial commit: a b h p q r
   
 
 
 Subcase: chaining "merged" information during a merge
 ``````````````````````````````````````````````````````
 
 When a non-rename change are merged with a copy overwrite, the merge pick the copy source from (p1) as the reference. We should preserve this information in subsequent merges.
 
   $ case_desc="chained merges (copy-overwrite -> simple) - same content"
 
 (extra unrelated changes)
 
   $ hg up 'desc("f-2")'
   2 files updated, 0 files merged, 2 files removed, 0 files unresolved (no-changeset !)
   1 files updated, 0 files merged, 2 files removed, 0 files unresolved (changeset !)
   $ echo n > unrelated-n
   $ hg add unrelated-n
   $ hg ci -m 'n-1: unrelated changes (based on the "f" series of changes)'
   created new head
 
   $ hg up 'desc("g-1")'
   2 files updated, 0 files merged, 1 files removed, 0 files unresolved
   $ echo o > unrelated-o
   $ hg add unrelated-o
   $ hg ci -m 'o-1: unrelated changes (based on "g" changes)'
   created new head
 
 (merge variant 1)
 
   $ hg up 'desc("mFGm")'
   1 files updated, 0 files merged, 2 files removed, 0 files unresolved (no-changeset !)
   0 files updated, 0 files merged, 2 files removed, 0 files unresolved (changeset !)
   $ hg merge 'desc("o-1")'
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
   (branch merge, don't forget to commit)
   $ hg ci -m "mFG,Om: $case_desc"
 
 (merge variant 2)
 
   $ hg up 'desc("o-1")'
   2 files updated, 0 files merged, 0 files removed, 0 files unresolved (no-changeset !)
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved (changeset !)
   $ hg merge 'desc("FGm")'
   1 files updated, 0 files merged, 1 files removed, 0 files unresolved (no-changeset !)
   0 files updated, 0 files merged, 1 files removed, 0 files unresolved (changeset !)
   (branch merge, don't forget to commit)
   $ hg ci -m "mO,FGm: $case_desc"
   created new head
 
 (merge variant 3)
 
   $ hg up 'desc("mGFm")'
   0 files updated, 0 files merged, 1 files removed, 0 files unresolved
   $ hg merge 'desc("n-1")'
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
   (branch merge, don't forget to commit)
   $ hg ci -m "mGF,Nm: $case_desc"
 
 (merge variant 4)
 
   $ hg up 'desc("n-1")'
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
   $ hg merge 'desc("mGFm")'
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
   (branch merge, don't forget to commit)
   $ hg ci -m "mN,GFm: $case_desc"
   created new head
 
   $ hg log -G --rev '::(desc("mFG,Om") + desc("mO,FGm") + desc("mGF,Nm") + desc("mN,GFm"))'
   @    mN,GFm: chained merges (copy-overwrite -> simple) - same content
   |\
   +---o  mGF,Nm: chained merges (copy-overwrite -> simple) - same content
   | |/
   | | o    mO,FGm: chained merges (copy-overwrite -> simple) - same content
   | | |\
   | | +---o  mFG,Om: chained merges (copy-overwrite -> simple) - same content
   | | | |/
   | | | o  o-1: unrelated changes (based on "g" changes)
   | | | |
   | o | |  n-1: unrelated changes (based on the "f" series of changes)
   | | | |
   o-----+  mGFm-0 merge - G side: content change, F side: copy overwrite, no content change - the other way
   |/ / /
   | o /  mFGm-0 merge - G side: content change, F side: copy overwrite, no content change - one way
   |/|/
   | o  g-1: update d
   | |
   o |  f-2: rename i -> d
   | |
   o |  f-1: rename h -> i
   |/
   o  i-2: c -move-> d, s -move-> t
   |
   o  i-1: a -move-> c, p -move-> s
   |
   o  i-0 initial commit: a b h p q r
   
 
 Subcase: chaining conflicting rename resolution, with extra change during the merge
 ```````````````````````````````````````````````````````````````````````````````````
 
 The "mEA-change-m-0" and "mAE-change-m-0" case create a rename tracking conflict on file 'f'. We
 add more change on the respective branch and merge again. These second merge
 does not involve the file 'f' and the arbitration done within "mAEm" and "mEA"
 about that file should stay unchanged.
 
   $ case_desc="chained merges (conflict+change -> simple) - same content on both branch in the initial merge"
 
 
 (merge variant 1)
 
   $ hg up 'desc("mAE-change-m")'
   2 files updated, 0 files merged, 3 files removed, 0 files unresolved
   $ hg merge 'desc("k-1")'
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
   (branch merge, don't forget to commit)
   $ hg ci -m "mAE-change,Km: $case_desc"
 
 (merge variant 2)
 
   $ hg up 'desc("k-1")'
   2 files updated, 0 files merged, 0 files removed, 0 files unresolved
 
   $ hg merge 'desc("mAE-change-m")'
   1 files updated, 0 files merged, 1 files removed, 0 files unresolved
   (branch merge, don't forget to commit)
   $ hg ci -m "mK,AE-change-m: $case_desc"
   created new head
 
 (merge variant 3)
 
   $ hg up 'desc("mEA-change-m")'
   1 files updated, 0 files merged, 1 files removed, 0 files unresolved
   $ hg merge 'desc("j-1")'
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
   (branch merge, don't forget to commit)
   $ hg ci -m "mEA-change,Jm: $case_desc"
 
 (merge variant 4)
 
   $ hg up 'desc("j-1")'
   2 files updated, 0 files merged, 0 files removed, 0 files unresolved
   $ hg merge 'desc("mEA-change-m")'
   1 files updated, 0 files merged, 1 files removed, 0 files unresolved
   (branch merge, don't forget to commit)
   $ hg ci -m "mJ,EA-change-m: $case_desc"
   created new head
 
 
   $ hg log -G --rev '::(desc("mAE-change,Km") + desc("mK,AE-change-m") + desc("mEA-change,Jm") + desc("mJ,EA-change-m"))'
   @    mJ,EA-change-m: chained merges (conflict+change -> simple) - same content on both branch in the initial merge
   |\
   +---o  mEA-change,Jm: chained merges (conflict+change -> simple) - same content on both branch in the initial merge
   | |/
   | | o    mK,AE-change-m: chained merges (conflict+change -> simple) - same content on both branch in the initial merge
   | | |\
   | | +---o  mAE-change,Km: chained merges (conflict+change -> simple) - same content on both branch in the initial merge
   | | | |/
   | | | o  k-1: unrelated changes (based on "e" changes)
   | | | |
   | o | |  j-1: unrelated changes (based on the "a" series of changes)
   | | | |
   o-----+  mEA-change-m-0 merge with file update and copies info on both side - A side: rename d to f, E side: b to f, (same content for f in parent) - the other way
   |/ / /
   | o /  mAE-change-m-0 merge with file update and copies info on both side - A side: rename d to f, E side: b to f, (same content for f in parent) - one way
   |/|/
   | o  e-2 g -move-> f
   | |
   | o  e-1 b -move-> g
   | |
   o |  a-2: e -move-> f
   | |
   o |  a-1: d -move-> e
   |/
   o  i-2: c -move-> d, s -move-> t
   |
   o  i-1: a -move-> c, p -move-> s
   |
   o  i-0 initial commit: a b h p q r
   
 
 Summary of all created cases
 ----------------------------
 
   $ hg up --quiet null
 
 (This exists to help keeping a compact list of the various cases we have built)
 
   $ hg log -T '{desc|firstline}\n'| sort
   a-1: d -move-> e
   a-2: e -move-> f
   b-1: b update
   c-1 delete d
   d-1 delete d
   d-2 re-add d
   e-1 b -move-> g
   e-2 g -move-> f
   f-1: rename h -> i
   f-2: rename i -> d
   g-1: update d
   h-1: b -(move)-> d
   i-0 initial commit: a b h p q r
   i-1: a -move-> c, p -move-> s
   i-2: c -move-> d, s -move-> t
   j-1: unrelated changes (based on the "a" series of changes)
   k-1: unrelated changes (based on "e" changes)
   l-1: unrelated changes (based on "c" changes)
   mABm-0 simple merge - A side: multiple renames, B side: unrelated update - the other way
   mAE,Km: chained merges (conflict -> simple) - same content everywhere
   mAE-change,Km: chained merges (conflict+change -> simple) - same content on both branch in the initial merge
   mAE-change-m-0 merge with file update and copies info on both side - A side: rename d to f, E side: b to f, (same content for f in parent) - one way
   mAEm-0 merge with copies info on both side - A side: rename d to f, E side: b to f, (same content for f) - one way
   mBAm-0 simple merge - A side: multiple renames, B side: unrelated update - one way
   mBC+revert,Lm: chained merges (salvaged -> simple) - same content (when the file exists)
   mBC-change-m-0 merge explicitely revive deleted file - B side: unrelated change, C side: delete d (restored by merge) - the other way
   mBC-revert-m-0 merge explicitely revive deleted file - B side: unrelated change, C side: delete d (restored by merge) - the other way
   mBCm-0 simple merge - C side: delete a file with copies history , B side: unrelated update - one way
   mBCm-1 re-add d
   mBDm-0 simple merge - B side: unrelated update, D side: delete and recreate a file (with different content) - one way
   mBF-change-m-0 merge with extra change - B side: unrelated change, F side: overwrite d with a copy (from h->i->d) - one way
   mBFm-0 simple merge - B side: unrelated change, F side: overwrite d with a copy (from h->i->d) - one way
   mBRm-0 simple merge - B side: unrelated change, R side: overwrite d with a copy (from r->x->t) different content - one way
   mCB+revert,Lm: chained merges (salvaged -> simple) - same content (when the file exists)
   mCB-change-m-0 merge explicitely revive deleted file - B side: unrelated change, C side: delete d (restored by merge) - one way
   mCB-revert-m-0 merge explicitely revive deleted file - B side: unrelated change, C side: delete d (restored by merge) - one way
   mCBm-0 simple merge - C side: delete a file with copies history , B side: unrelated update - the other way
   mCBm-1 re-add d
   mCGm-0 merge updated/deleted - revive the file (updated content) - one way
   mCH-delete-before-conflict-m-0 simple merge - C side: d is the results of renames then deleted, H side: d is result of another rename (same content as the other branch) - one way
   mDBm-0 simple merge - B side: unrelated update, D side: delete and recreate a file (with different content) - the other way
   mDGm-0 actual content merge, copies on one side - D side: delete and re-add (different content), G side: update content - one way
   mEA,Jm: chained merges (conflict -> simple) - same content everywhere
   mEA-change,Jm: chained merges (conflict+change -> simple) - same content on both branch in the initial merge
   mEA-change-m-0 merge with file update and copies info on both side - A side: rename d to f, E side: b to f, (same content for f in parent) - the other way
   mEAm-0 merge with copies info on both side - A side: rename d to f, E side: b to f, (same content for f) - the other way
   mFB-change-m-0 merge with extra change - B side: unrelated change, F side: overwrite d with a copy (from h->i->d) - the other way
   mFBm-0 simple merge - B side: unrelated change, F side: overwrite d with a copy (from h->i->d) - the other way
   mFG,Om: chained merges (copy-overwrite -> simple) - same content
   mFGm-0 merge - G side: content change, F side: copy overwrite, no content change - one way
   mGCm-0 merge updated/deleted - revive the file (updated content) - the other way
   mGDm-0 actual content merge, copies on one side - D side: delete and re-add (different content), G side: update content - the other way
   mGF,Nm: chained merges (copy-overwrite -> simple) - same content
   mGFm-0 merge - G side: content change, F side: copy overwrite, no content change - the other way
   mHC-delete-before-conflict-m-0 simple merge - C side: d is the results of renames then deleted, H side: d is result of another rename (same content as the other branch) - the other way
   mJ,EA-change-m: chained merges (conflict+change -> simple) - same content on both branch in the initial merge
   mJ,EAm: chained merges (conflict -> simple) - same content everywhere
   mK,AE-change-m: chained merges (conflict+change -> simple) - same content on both branch in the initial merge
   mK,AEm: chained merges (conflict -> simple) - same content everywhere
   mL,BC+revertm: chained merges (salvaged -> simple) - same content (when the file exists)
   mL,CB+revertm: chained merges (salvaged -> simple) - same content (when the file exists)
   mN,GFm: chained merges (copy-overwrite -> simple) - same content
   mO,FGm: chained merges (copy-overwrite -> simple) - same content
   mPQ,Tm: chained merges (conflict -> simple) - different content
   mPQm-0 merge with copies info on both side - P side: rename t to v, Q side: r to v, (different content) - one way
   mQP,Sm: chained merges (conflict -> simple) - different content
   mQPm-0 merge with copies info on both side - P side: rename t to v, Q side: r to v, (different content) - the other way
   mRBm-0 simple merge - B side: unrelated change, R side: overwrite d with a copy (from r->x->t) different content - the other way
   mS,QPm: chained merges (conflict -> simple) - different content
   mT,PQm: chained merges (conflict -> simple) - different content
   n-1: unrelated changes (based on the "f" series of changes)
   o-1: unrelated changes (based on "g" changes)
   p-1: t -move-> u
   p-2: u -move-> v
   q-1 r -move-> w
   q-2 w -move-> v
   r-1: rename r -> x
   r-2: rename t -> x
   s-1: unrelated changes (based on the "p" series of changes)
   t-1: unrelated changes (based on "q" changes)
 
 
 Test that sidedata computations during upgrades are correct
 ===========================================================
 
 We upgrade a repository that is not using sidedata (the filelog case) and
  check that the same side data have been generated as if they were computed at
  commit time.
 
 
 #if upgraded
   $ cat >> $HGRCPATH << EOF
   > [format]
   > exp-use-copies-side-data-changeset = yes
   > EOF
   $ hg debugformat -v | egrep 'changelog-v2|revlog-v2|copies-sdc'
   copies-sdc:          no    yes      no
   revlog-v2:           no     no      no
   changelog-v2:        no    yes      no
   $ hg debugupgraderepo --run --quiet
   upgrade will perform the following actions:
   
   requirements
      preserved: * (glob)
      added: exp-changelog-v2, exp-copies-sidedata-changeset
   
   processed revlogs:
-    - all-filelogs
     - changelog
-    - manifest
   
 #endif
 
 #if upgraded-parallel
   $ cat >> $HGRCPATH << EOF
   > [format]
   > exp-use-copies-side-data-changeset = yes
   > [experimental]
   > worker.repository-upgrade=yes
   > [worker]
   > enabled=yes
   > numcpus=8
   > EOF
   $ hg debugformat -v  | egrep 'changelog-v2|revlog-v2|copies-sdc'
   copies-sdc:          no    yes      no
   revlog-v2:           no     no      no
   changelog-v2:        no    yes      no
   $ hg debugupgraderepo --run --quiet
   upgrade will perform the following actions:
   
   requirements
      preserved: * (glob)
      added: exp-changelog-v2, exp-copies-sidedata-changeset
   
   processed revlogs:
-    - all-filelogs
     - changelog
-    - manifest
   
 #endif
 
 #if pull
   $ cd ..
   $ mv repo-chain repo-source
   $ hg init repo-chain
   $ cd repo-chain
   $ hg pull ../repo-source
   pulling from ../repo-source
   requesting all changes
   adding changesets
   adding manifests
   adding file changes
   added 80 changesets with 44 changes to 25 files (+39 heads)
   new changesets a3a31bbefea6:908ce9259ffa
   (run 'hg heads' to see heads, 'hg merge' to merge)
 #endif
 
 #if pull-upgrade
   $ cat >> $HGRCPATH << EOF
   > [format]
   > exp-use-copies-side-data-changeset = yes
   > [experimental]
   > changegroup4 = yes
   > EOF
   $ cd ..
   $ mv repo-chain repo-source
   $ hg init repo-chain
   $ cd repo-chain
   $ hg pull ../repo-source
   pulling from ../repo-source
   requesting all changes
   adding changesets
   adding manifests
   adding file changes
   added 80 changesets with 44 changes to 25 files (+39 heads)
   new changesets a3a31bbefea6:908ce9259ffa
   (run 'hg heads' to see heads, 'hg merge' to merge)
 #endif
 
 #if push
   $ cd ..
   $ mv repo-chain repo-source
   $ hg init repo-chain
   $ cd repo-source
   $ hg push ../repo-chain
   pushing to ../repo-chain
   searching for changes
   adding changesets
   adding manifests
   adding file changes
   added 80 changesets with 44 changes to 25 files (+39 heads)
   $ cd ../repo-chain
 #endif
 
 #if push-upgrade
   $ cat >> $HGRCPATH << EOF
   > [format]
   > exp-use-copies-side-data-changeset = yes
   > [experimental]
   > changegroup4 = yes
   > EOF
   $ cd ..
   $ mv repo-chain repo-source
   $ hg init repo-chain
   $ cd repo-source
   $ hg push ../repo-chain
   pushing to ../repo-chain
   searching for changes
   adding changesets
   adding manifests
   adding file changes
   added 80 changesets with 44 changes to 25 files (+39 heads)
   $ cd ../repo-chain
 #endif
 
 #if no-compatibility no-filelog no-changeset
 
   $ hg debugchangedfiles --compute 0
   added      : a, ;
   added      : b, ;
   added      : h, ;
   added      : p, ;
   added      : q, ;
   added      : r, ;
 
   $ for rev in `hg log --rev 'all()' -T '{rev}\n'`; do
   >     case_id=`hg log -r $rev -T '{word(0, desc, ":")}\n'`
   >     echo "##### revision \"$case_id\" #####"
   >     hg debugsidedata -c -v -- $rev
   >     hg debugchangedfiles $rev
   > done
   ##### revision "i-0 initial commit" #####
   1 sidedata entries
    entry-0014 size 64
     '\x00\x00\x00\x06\x04\x00\x00\x00\x01\x00\x00\x00\x00\x04\x00\x00\x00\x02\x00\x00\x00\x00\x04\x00\x00\x00\x03\x00\x00\x00\x00\x04\x00\x00\x00\x04\x00\x00\x00\x00\x04\x00\x00\x00\x05\x00\x00\x00\x00\x04\x00\x00\x00\x06\x00\x00\x00\x00abhpqr'
   added      : a, ;
   added      : b, ;
   added      : h, ;
   added      : p, ;
   added      : q, ;
   added      : r, ;
   ##### revision "i-1" #####
   1 sidedata entries
    entry-0014 size 44
     '\x00\x00\x00\x04\x0c\x00\x00\x00\x01\x00\x00\x00\x00\x06\x00\x00\x00\x02\x00\x00\x00\x00\x0c\x00\x00\x00\x03\x00\x00\x00\x00\x06\x00\x00\x00\x04\x00\x00\x00\x02acps'
   removed    : a, ;
   added    p1: c, a;
   removed    : p, ;
   added    p1: s, p;
   ##### revision "i-2" #####
   1 sidedata entries
    entry-0014 size 44
     '\x00\x00\x00\x04\x0c\x00\x00\x00\x01\x00\x00\x00\x00\x06\x00\x00\x00\x02\x00\x00\x00\x00\x0c\x00\x00\x00\x03\x00\x00\x00\x00\x06\x00\x00\x00\x04\x00\x00\x00\x02cdst'
   removed    : c, ;
   added    p1: d, c;
   removed    : s, ;
   added    p1: t, s;
   ##### revision "a-1" #####
   1 sidedata entries
    entry-0014 size 24
     '\x00\x00\x00\x02\x0c\x00\x00\x00\x01\x00\x00\x00\x00\x06\x00\x00\x00\x02\x00\x00\x00\x00de'
   removed    : d, ;
   added    p1: e, d;
   ##### revision "a-2" #####
   1 sidedata entries
    entry-0014 size 24
     '\x00\x00\x00\x02\x0c\x00\x00\x00\x01\x00\x00\x00\x00\x06\x00\x00\x00\x02\x00\x00\x00\x00ef'
   removed    : e, ;
   added    p1: f, e;
   ##### revision "b-1" #####
   1 sidedata entries
    entry-0014 size 14
     '\x00\x00\x00\x01\x14\x00\x00\x00\x01\x00\x00\x00\x00b'
   touched    : b, ;
   ##### revision "c-1 delete d" #####
   1 sidedata entries
    entry-0014 size 14
     '\x00\x00\x00\x01\x0c\x00\x00\x00\x01\x00\x00\x00\x00d'
   removed    : d, ;
   ##### revision "d-1 delete d" #####
   1 sidedata entries
    entry-0014 size 14
     '\x00\x00\x00\x01\x0c\x00\x00\x00\x01\x00\x00\x00\x00d'
   removed    : d, ;
   ##### revision "d-2 re-add d" #####
   1 sidedata entries
    entry-0014 size 14
     '\x00\x00\x00\x01\x04\x00\x00\x00\x01\x00\x00\x00\x00d'
   added      : d, ;
   ##### revision "e-1 b -move-> g" #####
   1 sidedata entries
    entry-0014 size 24
     '\x00\x00\x00\x02\x0c\x00\x00\x00\x01\x00\x00\x00\x00\x06\x00\x00\x00\x02\x00\x00\x00\x00bg'
   removed    : b, ;
   added    p1: g, b;
   ##### revision "e-2 g -move-> f" #####
   1 sidedata entries
    entry-0014 size 24
     '\x00\x00\x00\x02\x06\x00\x00\x00\x01\x00\x00\x00\x01\x0c\x00\x00\x00\x02\x00\x00\x00\x00fg'
   added    p1: f, g;
   removed    : g, ;
   ##### revision "p-1" #####
   1 sidedata entries
    entry-0014 size 24
     '\x00\x00\x00\x02\x0c\x00\x00\x00\x01\x00\x00\x00\x00\x06\x00\x00\x00\x02\x00\x00\x00\x00tu'
   removed    : t, ;
   added    p1: u, t;
   ##### revision "p-2" #####
   1 sidedata entries
    entry-0014 size 24
     '\x00\x00\x00\x02\x0c\x00\x00\x00\x01\x00\x00\x00\x00\x06\x00\x00\x00\x02\x00\x00\x00\x00uv'
   removed    : u, ;
   added    p1: v, u;
   ##### revision "q-1 r -move-> w" #####
   1 sidedata entries
    entry-0014 size 24
     '\x00\x00\x00\x02\x0c\x00\x00\x00\x01\x00\x00\x00\x00\x06\x00\x00\x00\x02\x00\x00\x00\x00rw'
   removed    : r, ;
   added    p1: w, r;
   ##### revision "q-2 w -move-> v" #####
   1 sidedata entries
    entry-0014 size 24
     '\x00\x00\x00\x02\x06\x00\x00\x00\x01\x00\x00\x00\x01\x0c\x00\x00\x00\x02\x00\x00\x00\x00vw'
   added    p1: v, w;
   removed    : w, ;
   ##### revision "mBAm-0 simple merge - A side" #####
   1 sidedata entries
    entry-0014 size 4
     '\x00\x00\x00\x00'
   ##### revision "mABm-0 simple merge - A side" #####
   1 sidedata entries
    entry-0014 size 4
     '\x00\x00\x00\x00'
   ##### revision "mBCm-0 simple merge - C side" #####
   1 sidedata entries
    entry-0014 size 4
     '\x00\x00\x00\x00'
   ##### revision "mBCm-1 re-add d" #####
   1 sidedata entries
    entry-0014 size 14
     '\x00\x00\x00\x01\x04\x00\x00\x00\x01\x00\x00\x00\x00d'
   added      : d, ;
   ##### revision "mCBm-0 simple merge - C side" #####
   1 sidedata entries
    entry-0014 size 4
     '\x00\x00\x00\x00'
   ##### revision "mCBm-1 re-add d" #####
   1 sidedata entries
    entry-0014 size 14
     '\x00\x00\x00\x01\x04\x00\x00\x00\x01\x00\x00\x00\x00d'
   added      : d, ;
   ##### revision "mBDm-0 simple merge - B side" #####
   1 sidedata entries
    entry-0014 size 4
     '\x00\x00\x00\x00'
   ##### revision "mDBm-0 simple merge - B side" #####
   1 sidedata entries
    entry-0014 size 4
     '\x00\x00\x00\x00'
   ##### revision "mAEm-0 merge with copies info on both side - A side" #####
   1 sidedata entries
    entry-0014 size 14
     '\x00\x00\x00\x01\x08\x00\x00\x00\x01\x00\x00\x00\x00f'
   merged     : f, ;
   ##### revision "mEAm-0 merge with copies info on both side - A side" #####
   1 sidedata entries
    entry-0014 size 14
     '\x00\x00\x00\x01\x08\x00\x00\x00\x01\x00\x00\x00\x00f'
   merged     : f, ;
   ##### revision "mPQm-0 merge with copies info on both side - P side" #####
   1 sidedata entries
    entry-0014 size 14
     '\x00\x00\x00\x01\x08\x00\x00\x00\x01\x00\x00\x00\x00v'
   merged     : v, ;
   ##### revision "mQPm-0 merge with copies info on both side - P side" #####
   1 sidedata entries
    entry-0014 size 14
     '\x00\x00\x00\x01\x08\x00\x00\x00\x01\x00\x00\x00\x00v'
   merged     : v, ;
   ##### revision "f-1" #####
   1 sidedata entries
    entry-0014 size 24
     '\x00\x00\x00\x02\x0c\x00\x00\x00\x01\x00\x00\x00\x00\x06\x00\x00\x00\x02\x00\x00\x00\x00hi'
   removed    : h, ;
   added    p1: i, h;
   ##### revision "f-2" #####
   1 sidedata entries
    entry-0014 size 24
     '\x00\x00\x00\x02\x16\x00\x00\x00\x01\x00\x00\x00\x01\x0c\x00\x00\x00\x02\x00\x00\x00\x00di'
   touched  p1: d, i;
   removed    : i, ;
   ##### revision "mBFm-0 simple merge - B side" #####
   1 sidedata entries
    entry-0014 size 4
     '\x00\x00\x00\x00'
   ##### revision "mFBm-0 simple merge - B side" #####
   1 sidedata entries
    entry-0014 size 4
     '\x00\x00\x00\x00'
   ##### revision "r-1" #####
   1 sidedata entries
    entry-0014 size 24
     '\x00\x00\x00\x02\x0c\x00\x00\x00\x01\x00\x00\x00\x00\x06\x00\x00\x00\x02\x00\x00\x00\x00rx'
   removed    : r, ;
   added    p1: x, r;
   ##### revision "r-2" #####
   1 sidedata entries
    entry-0014 size 24
     '\x00\x00\x00\x02\x16\x00\x00\x00\x01\x00\x00\x00\x01\x0c\x00\x00\x00\x02\x00\x00\x00\x00tx'
   touched  p1: t, x;
   removed    : x, ;
   ##### revision "mBRm-0 simple merge - B side" #####
   1 sidedata entries
    entry-0014 size 4
     '\x00\x00\x00\x00'
   ##### revision "mRBm-0 simple merge - B side" #####
   1 sidedata entries
    entry-0014 size 4
     '\x00\x00\x00\x00'
   ##### revision "g-1" #####
   1 sidedata entries
    entry-0014 size 14
     '\x00\x00\x00\x01\x14\x00\x00\x00\x01\x00\x00\x00\x00d'
   touched    : d, ;
   ##### revision "mDGm-0 actual content merge, copies on one side - D side" #####
   1 sidedata entries
    entry-0014 size 14
     '\x00\x00\x00\x01\x08\x00\x00\x00\x01\x00\x00\x00\x00d'
   merged     : d, ;
   ##### revision "mGDm-0 actual content merge, copies on one side - D side" #####
   1 sidedata entries
    entry-0014 size 14
     '\x00\x00\x00\x01\x08\x00\x00\x00\x01\x00\x00\x00\x00d'
   merged     : d, ;
   ##### revision "mFGm-0 merge - G side" #####
   1 sidedata entries
    entry-0014 size 14
     '\x00\x00\x00\x01\x08\x00\x00\x00\x01\x00\x00\x00\x00d'
   merged     : d, ;
   ##### revision "mGFm-0 merge - G side" #####
   1 sidedata entries
    entry-0014 size 14
     '\x00\x00\x00\x01\x08\x00\x00\x00\x01\x00\x00\x00\x00d'
   merged     : d, ;
   ##### revision "mCGm-0 merge updated/deleted - revive the file (updated content) - one way" #####
   1 sidedata entries
    entry-0014 size 14
     '\x00\x00\x00\x01\x10\x00\x00\x00\x01\x00\x00\x00\x00d'
   salvaged   : d, ;
   ##### revision "mGCm-0 merge updated/deleted - revive the file (updated content) - the other way" #####
   1 sidedata entries
    entry-0014 size 14
     '\x00\x00\x00\x01\x10\x00\x00\x00\x01\x00\x00\x00\x00d'
   salvaged   : d, ;
   ##### revision "mCB-revert-m-0 merge explicitely revive deleted file - B side" #####
   1 sidedata entries
    entry-0014 size 14
     '\x00\x00\x00\x01\x10\x00\x00\x00\x01\x00\x00\x00\x00d'
   salvaged   : d, ;
   ##### revision "mBC-revert-m-0 merge explicitely revive deleted file - B side" #####
   1 sidedata entries
    entry-0014 size 14
     '\x00\x00\x00\x01\x10\x00\x00\x00\x01\x00\x00\x00\x00d'
   salvaged   : d, ;
   ##### revision "h-1" #####
   1 sidedata entries
    entry-0014 size 24
     '\x00\x00\x00\x02\x0c\x00\x00\x00\x01\x00\x00\x00\x00\x06\x00\x00\x00\x02\x00\x00\x00\x00bd'
   removed    : b, ;
   added    p1: d, b;
   ##### revision "mCH-delete-before-conflict-m-0 simple merge - C side" #####
   1 sidedata entries
    entry-0014 size 4
     '\x00\x00\x00\x00'
   ##### revision "mHC-delete-before-conflict-m-0 simple merge - C side" #####
   1 sidedata entries
    entry-0014 size 4
     '\x00\x00\x00\x00'
   ##### revision "mAE-change-m-0 merge with file update and copies info on both side - A side" #####
   1 sidedata entries
    entry-0014 size 14
     '\x00\x00\x00\x01\x08\x00\x00\x00\x01\x00\x00\x00\x00f'
   merged     : f, ;
   ##### revision "mEA-change-m-0 merge with file update and copies info on both side - A side" #####
   1 sidedata entries
    entry-0014 size 14
     '\x00\x00\x00\x01\x08\x00\x00\x00\x01\x00\x00\x00\x00f'
   merged     : f, ;
   ##### revision "mBF-change-m-0 merge with extra change - B side" #####
   1 sidedata entries
    entry-0014 size 14
     '\x00\x00\x00\x01\x14\x00\x00\x00\x01\x00\x00\x00\x00d'
   touched    : d, ;
   ##### revision "mFB-change-m-0 merge with extra change - B side" #####
   1 sidedata entries
    entry-0014 size 14
     '\x00\x00\x00\x01\x14\x00\x00\x00\x01\x00\x00\x00\x00d'
   touched    : d, ;
   ##### revision "mCB-change-m-0 merge explicitely revive deleted file - B side" #####
   1 sidedata entries
    entry-0014 size 14
     '\x00\x00\x00\x01\x10\x00\x00\x00\x01\x00\x00\x00\x00d'
   salvaged   : d, ;
   ##### revision "mBC-change-m-0 merge explicitely revive deleted file - B side" #####
   1 sidedata entries
    entry-0014 size 14
     '\x00\x00\x00\x01\x10\x00\x00\x00\x01\x00\x00\x00\x00d'
   salvaged   : d, ;
   ##### revision "j-1" #####
   1 sidedata entries
    entry-0014 size 24
     '\x00\x00\x00\x01\x04\x00\x00\x00\x0b\x00\x00\x00\x00unrelated-j'
   added      : unrelated-j, ;
   ##### revision "k-1" #####
   1 sidedata entries
    entry-0014 size 24
     '\x00\x00\x00\x01\x04\x00\x00\x00\x0b\x00\x00\x00\x00unrelated-k'
   added      : unrelated-k, ;
   ##### revision "mAE,Km" #####
   1 sidedata entries
    entry-0014 size 4
     '\x00\x00\x00\x00'
   ##### revision "mK,AEm" #####
   1 sidedata entries
    entry-0014 size 4
     '\x00\x00\x00\x00'
   ##### revision "mEA,Jm" #####
   1 sidedata entries
    entry-0014 size 24
     '\x00\x00\x00\x01\x14\x00\x00\x00\x0b\x00\x00\x00\x00unrelated-j'
   touched    : unrelated-j, ;
   ##### revision "mJ,EAm" #####
   1 sidedata entries
    entry-0014 size 24
     '\x00\x00\x00\x01\x14\x00\x00\x00\x0b\x00\x00\x00\x00unrelated-j'
   touched    : unrelated-j, ;
   ##### revision "s-1" #####
   1 sidedata entries
    entry-0014 size 24
     '\x00\x00\x00\x01\x04\x00\x00\x00\x0b\x00\x00\x00\x00unrelated-s'
   added      : unrelated-s, ;
   ##### revision "t-1" #####
   1 sidedata entries
    entry-0014 size 24
     '\x00\x00\x00\x01\x04\x00\x00\x00\x0b\x00\x00\x00\x00unrelated-t'
   added      : unrelated-t, ;
   ##### revision "mPQ,Tm" #####
   1 sidedata entries
    entry-0014 size 4
     '\x00\x00\x00\x00'
   ##### revision "mT,PQm" #####
   1 sidedata entries
    entry-0014 size 4
     '\x00\x00\x00\x00'
   ##### revision "mQP,Sm" #####
   1 sidedata entries
    entry-0014 size 4
     '\x00\x00\x00\x00'
   ##### revision "mS,QPm" #####
   1 sidedata entries
    entry-0014 size 4
     '\x00\x00\x00\x00'
   ##### revision "l-1" #####
   1 sidedata entries
    entry-0014 size 24
     '\x00\x00\x00\x01\x04\x00\x00\x00\x0b\x00\x00\x00\x00unrelated-l'
   added      : unrelated-l, ;
   ##### revision "mBC+revert,Lm" #####
   1 sidedata entries
    entry-0014 size 4
     '\x00\x00\x00\x00'
   ##### revision "mCB+revert,Lm" #####
   1 sidedata entries
    entry-0014 size 4
     '\x00\x00\x00\x00'
   ##### revision "mL,BC+revertm" #####
   1 sidedata entries
    entry-0014 size 4
     '\x00\x00\x00\x00'
   ##### revision "mL,CB+revertm" #####
   1 sidedata entries
    entry-0014 size 4
     '\x00\x00\x00\x00'
   ##### revision "n-1" #####
   1 sidedata entries
    entry-0014 size 24
     '\x00\x00\x00\x01\x04\x00\x00\x00\x0b\x00\x00\x00\x00unrelated-n'
   added      : unrelated-n, ;
   ##### revision "o-1" #####
   1 sidedata entries
    entry-0014 size 24
     '\x00\x00\x00\x01\x04\x00\x00\x00\x0b\x00\x00\x00\x00unrelated-o'
   added      : unrelated-o, ;
   ##### revision "mFG,Om" #####
   1 sidedata entries
    entry-0014 size 4
     '\x00\x00\x00\x00'
   ##### revision "mO,FGm" #####
   1 sidedata entries
    entry-0014 size 4
     '\x00\x00\x00\x00'
   ##### revision "mGF,Nm" #####
   1 sidedata entries
    entry-0014 size 4
     '\x00\x00\x00\x00'
   ##### revision "mN,GFm" #####
   1 sidedata entries
    entry-0014 size 4
     '\x00\x00\x00\x00'
   ##### revision "mAE-change,Km" #####
   1 sidedata entries
    entry-0014 size 4
     '\x00\x00\x00\x00'
   ##### revision "mK,AE-change-m" #####
   1 sidedata entries
    entry-0014 size 4
     '\x00\x00\x00\x00'
   ##### revision "mEA-change,Jm" #####
   1 sidedata entries
    entry-0014 size 4
     '\x00\x00\x00\x00'
   ##### revision "mJ,EA-change-m" #####
   1 sidedata entries
    entry-0014 size 4
     '\x00\x00\x00\x00'
 
 #endif
 
 
 Test copy information chaining
 ==============================
 
 Check that matching only affect the destination and not intermediate path
 -------------------------------------------------------------------------
 
 The two status call should give the same value for f
 
   $ hg status --copies --rev 'desc("i-0")' --rev 'desc("a-2")'
   A f
     a
   A t
     p
   R a
   R p
   $ hg status --copies --rev 'desc("i-0")' --rev 'desc("a-2")' f
   A f
     a (no-changeset no-compatibility !)
 
 merging with unrelated change does not interfere with the renames
 ---------------------------------------------------------------
 
 - rename on one side
 - unrelated change on the other side
 
   $ hg log -G --rev '::(desc("mABm")+desc("mBAm"))'
   o    mABm-0 simple merge - A side: multiple renames, B side: unrelated update - the other way
   |\
   +---o  mBAm-0 simple merge - A side: multiple renames, B side: unrelated update - one way
   | |/
   | o  b-1: b update
   | |
   o |  a-2: e -move-> f
   | |
   o |  a-1: d -move-> e
   |/
   o  i-2: c -move-> d, s -move-> t
   |
   o  i-1: a -move-> c, p -move-> s
   |
   o  i-0 initial commit: a b h p q r
   
 
   $ hg status --copies --rev 'desc("b-1")' --rev 'desc("mABm")'
   A f
     d
   R d
   $ hg status --copies --rev 'desc("b-1")' --rev 'desc("mBAm")'
   A f
     d
   R d
   $ hg status --copies --rev 'desc("a-2")' --rev 'desc("mABm")'
   M b
   $ hg status --copies --rev 'desc("a-2")' --rev 'desc("mBAm")'
   M b
   $ hg status --copies --rev 'desc("i-2")' --rev 'desc("mABm")'
   M b
   A f
     d
   R d
   $ hg status --copies --rev 'desc("i-2")' --rev 'desc("mBAm")'
   M b
   A f
     d
   R d
   $ hg status --copies --rev 'desc("i-0")' --rev 'desc("mABm")'
   M b
   A f
     a
   A t
     p
   R a
   R p
   $ hg status --copies --rev 'desc("i-0")' --rev 'desc("mBAm")'
   M b
   A f
     a
   A t
     p
   R a
   R p
 
 merging with the side having a delete
 -------------------------------------
 
 case summary:
 - one with change to an unrelated file
 - one deleting the change
 and recreate an unrelated file after the merge
 
   $ hg log -G --rev '::(desc("mCBm")+desc("mBCm"))'
   o  mCBm-1 re-add d
   |
   o    mCBm-0 simple merge - C side: delete a file with copies history , B side: unrelated update - the other way
   |\
   | | o  mBCm-1 re-add d
   | | |
   +---o  mBCm-0 simple merge - C side: delete a file with copies history , B side: unrelated update - one way
   | |/
   | o  c-1 delete d
   | |
   o |  b-1: b update
   |/
   o  i-2: c -move-> d, s -move-> t
   |
   o  i-1: a -move-> c, p -move-> s
   |
   o  i-0 initial commit: a b h p q r
   
 - comparing from the merge
 
   $ hg status --copies --rev 'desc("b-1")' --rev 'desc("mBCm-0")'
   R d
   $ hg status --copies --rev 'desc("b-1")' --rev 'desc("mCBm-0")'
   R d
   $ hg status --copies --rev 'desc("c-1")' --rev 'desc("mBCm-0")'
   M b
   $ hg status --copies --rev 'desc("c-1")' --rev 'desc("mCBm-0")'
   M b
   $ hg status --copies --rev 'desc("i-2")' --rev 'desc("mBCm-0")'
   M b
   R d
   $ hg status --copies --rev 'desc("i-2")' --rev 'desc("mCBm-0")'
   M b
   R d
   $ hg status --copies --rev 'desc("i-0")' --rev 'desc("mBCm-0")'
   M b
   A t
     p
   R a
   R p
   $ hg status --copies --rev 'desc("i-0")' --rev 'desc("mCBm-0")'
   M b
   A t
     p
   R a
   R p
 
 - comparing with the merge children re-adding the file
 
   $ hg status --copies --rev 'desc("b-1")' --rev 'desc("mBCm-1")'
   M d
   $ hg status --copies --rev 'desc("b-1")' --rev 'desc("mCBm-1")'
   M d
   $ hg status --copies --rev 'desc("c-1")' --rev 'desc("mBCm-1")'
   M b
   A d
   $ hg status --copies --rev 'desc("c-1")' --rev 'desc("mCBm-1")'
   M b
   A d
   $ hg status --copies --rev 'desc("i-2")' --rev 'desc("mBCm-1")'
   M b
   M d
   $ hg status --copies --rev 'desc("i-2")' --rev 'desc("mCBm-1")'
   M b
   M d
   $ hg status --copies --rev 'desc("i-0")' --rev 'desc("mBCm-1")'
   M b
   A d
   A t
     p
   R a
   R p
   $ hg status --copies --rev 'desc("i-0")' --rev 'desc("mCBm-1")'
   M b
   A d
   A t
     p
   R a
   R p
 
 Comparing with a merge re-adding the file afterward
 ---------------------------------------------------
 
 Merge:
 - one with change to an unrelated file
 - one deleting and recreating the change
 
   $ hg log -G --rev '::(desc("mDBm")+desc("mBDm"))'
   o    mDBm-0 simple merge - B side: unrelated update, D side: delete and recreate a file (with different content) - the other way
   |\
   +---o  mBDm-0 simple merge - B side: unrelated update, D side: delete and recreate a file (with different content) - one way
   | |/
   | o  d-2 re-add d
   | |
   | o  d-1 delete d
   | |
   o |  b-1: b update
   |/
   o  i-2: c -move-> d, s -move-> t
   |
   o  i-1: a -move-> c, p -move-> s
   |
   o  i-0 initial commit: a b h p q r
   
   $ hg status --copies --rev 'desc("b-1")' --rev 'desc("mBDm-0")'
   M d
   $ hg status --copies --rev 'desc("b-1")' --rev 'desc("mDBm-0")'
   M d
   $ hg status --copies --rev 'desc("d-2")' --rev 'desc("mBDm-0")'
   M b
   $ hg status --copies --rev 'desc("d-2")' --rev 'desc("mDBm-0")'
   M b
   $ hg status --copies --rev 'desc("i-2")' --rev 'desc("mBDm-0")'
   M b
   M d
   $ hg status --copies --rev 'desc("i-2")' --rev 'desc("mDBm-0")'
   M b
   M d
 
 The bugs makes recorded copy is different depending of where we started the merge from since
 
   $ hg manifest --debug --rev 'desc("mBDm-0")' | grep '644   d'
   b004912a8510032a0350a74daa2803dadfb00e12 644   d
   $ hg manifest --debug --rev 'desc("mDBm-0")' | grep '644   d'
   b004912a8510032a0350a74daa2803dadfb00e12 644   d
 
   $ hg manifest --debug --rev 'desc("d-2")' | grep '644   d'
   b004912a8510032a0350a74daa2803dadfb00e12 644   d
   $ hg manifest --debug --rev 'desc("b-1")' | grep '644   d'
   d8252ab2e760b0d4e5288fd44cbd15a0fa567e16 644   d (no-changeset !)
   ae258f702dfeca05bf9b6a22a97a4b5645570f11 644   d (changeset !)
   $ hg debugindex d | head -n 4 | "$PYTHON" ../no-linkrev
      rev linkrev nodeid       p1           p2
        0       * d8252ab2e760 000000000000 000000000000 (no-changeset !)
        0       * ae258f702dfe 000000000000 000000000000 (changeset !)
        1       * b004912a8510 000000000000 000000000000
        2       * 7b79e2fe0c89 000000000000 000000000000 (no-changeset !)
        2       * 5cce88bf349f ae258f702dfe 000000000000 (changeset !)
 
 Log output should not include a merge commit as it did not happen
 
   $ hg log -Gfr 'desc("mBDm-0")' d
   o  d-2 re-add d
   |
   ~
 
   $ hg log -Gfr 'desc("mDBm-0")' d
   o  d-2 re-add d
   |
   ~
 
   $ hg status --copies --rev 'desc("i-0")' --rev 'desc("mBDm-0")'
   M b
   A d
   A t
     p
   R a
   R p
   $ hg status --copies --rev 'desc("i-0")' --rev 'desc("mDBm-0")'
   M b
   A d
   A t
     p
   R a
   R p
 
 
 Comparing with a merge with colliding rename
 --------------------------------------------
 
 Subcase: new copy information on both side
 ``````````````````````````````````````````
 
 - the "e-" branch renaming b to f (through 'g')
 - the "a-" branch renaming d to f (through e)
 
   $ hg log -G --rev '::(desc("mAEm")+desc("mEAm"))'
   o    mEAm-0 merge with copies info on both side - A side: rename d to f, E side: b to f, (same content for f) - the other way
   |\
   +---o  mAEm-0 merge with copies info on both side - A side: rename d to f, E side: b to f, (same content for f) - one way
   | |/
   | o  e-2 g -move-> f
   | |
   | o  e-1 b -move-> g
   | |
   o |  a-2: e -move-> f
   | |
   o |  a-1: d -move-> e
   |/
   o  i-2: c -move-> d, s -move-> t
   |
   o  i-1: a -move-> c, p -move-> s
   |
   o  i-0 initial commit: a b h p q r
   
 #if no-changeset
   $ hg manifest --debug --rev 'desc("mAEm-0")' | grep '644   f'
   2ff93c643948464ee1f871867910ae43a45b0bea 644   f
   $ hg manifest --debug --rev 'desc("mEAm-0")' | grep '644   f'
   2ff93c643948464ee1f871867910ae43a45b0bea 644   f
   $ hg manifest --debug --rev 'desc("a-2")' | grep '644   f'
   b76eb76580df486c3d51d63c5c210d4dd43a8ac7 644   f
   $ hg manifest --debug --rev 'desc("e-2")' | grep '644   f'
   e8825b386367b29fec957283a80bb47b47483fe1 644   f
   $ hg debugindex f | "$PYTHON" ../no-linkrev
      rev linkrev nodeid       p1           p2
        0       * b76eb76580df 000000000000 000000000000
        1       * e8825b386367 000000000000 000000000000
        2       * 2ff93c643948 b76eb76580df e8825b386367
        3       * 2f649fba7eb2 b76eb76580df e8825b386367
        4       * 774e7c1637d5 e8825b386367 b76eb76580df
 #else
   $ hg manifest --debug --rev 'desc("mAEm-0")' | grep '644   f'
   ae258f702dfeca05bf9b6a22a97a4b5645570f11 644   f
   $ hg manifest --debug --rev 'desc("mEAm-0")' | grep '644   f'
   ae258f702dfeca05bf9b6a22a97a4b5645570f11 644   f
   $ hg manifest --debug --rev 'desc("a-2")' | grep '644   f'
   ae258f702dfeca05bf9b6a22a97a4b5645570f11 644   f
   $ hg manifest --debug --rev 'desc("e-2")' | grep '644   f'
   ae258f702dfeca05bf9b6a22a97a4b5645570f11 644   f
   $ hg debugindex f | "$PYTHON" ../no-linkrev
      rev linkrev nodeid       p1           p2
        0       * ae258f702dfe 000000000000 000000000000
        1       * d3613c1ec831 ae258f702dfe 000000000000
        2       * 05e03c868bbc ae258f702dfe 000000000000
 #endif
 
 # Here the filelog based implementation is not looking at the rename
 # information (because the file exist on both side). However the changelog
 # based on works fine. We have different output.
 
   $ hg status --copies --rev 'desc("a-2")' --rev 'desc("mAEm-0")'
   M f (no-changeset !)
     b (no-filelog no-changeset !)
   R b
   $ hg status --copies --rev 'desc("a-2")' --rev 'desc("mEAm-0")'
   M f (no-changeset !)
     b (no-filelog no-changeset !)
   R b
   $ hg status --copies --rev 'desc("e-2")' --rev 'desc("mAEm-0")'
   M f (no-changeset !)
     d (no-filelog no-changeset !)
   R d
   $ hg status --copies --rev 'desc("e-2")' --rev 'desc("mEAm-0")'
   M f (no-changeset !)
     d (no-filelog no-changeset !)
   R d
   $ hg status --copies --rev 'desc("i-2")' --rev 'desc("a-2")'
   A f
     d
   R d
   $ hg status --copies --rev 'desc("i-2")' --rev 'desc("e-2")'
   A f
     b
   R b
 
 # From here, we run status against revision where both source file exists.
 #
 # The filelog based implementation picks an arbitrary side based on revision
 # numbers. So the same side "wins" whatever the parents order is. This is
 # sub-optimal because depending on revision numbers means the result can be
 # different from one repository to the next.
 #
 # The changeset based algorithm use the parent order to break tie on conflicting
 # information and will have a different order depending on who is p1 and p2.
 # That order is stable accross repositories. (data from p1 prevails)
 
   $ hg status --copies --rev 'desc("i-2")' --rev 'desc("mAEm-0")'
   A f
     d
   R b
   R d
   $ hg status --copies --rev 'desc("i-2")' --rev 'desc("mEAm-0")'
   A f
     d (filelog !)
     b (no-filelog !)
   R b
   R d
   $ hg status --copies --rev 'desc("i-0")' --rev 'desc("mAEm-0")'
   A f
     a
   A t
     p
   R a
   R b
   R p
   $ hg status --copies --rev 'desc("i-0")' --rev 'desc("mEAm-0")'
   A f
     a (filelog !)
     b (no-filelog !)
   A t
     p
   R a
   R b
   R p
 
 
 Subcase: existing copy information overwritten on one branch
 ````````````````````````````````````````````````````````````
 
 Note:
 | In this case, one of the merge wrongly record a merge while there is none.
 | This lead to bad copy tracing information to be dug up.
 
 
 Merge:
 - one with change to an unrelated file (b)
 - one overwriting a file (d) with a rename (from h to i to d)
 
   $ hg log -G --rev '::(desc("mBFm")+desc("mFBm"))'
   o    mFBm-0 simple merge - B side: unrelated change, F side: overwrite d with a copy (from h->i->d) - the other way
   |\
   +---o  mBFm-0 simple merge - B side: unrelated change, F side: overwrite d with a copy (from h->i->d) - one way
   | |/
   | o  f-2: rename i -> d
   | |
   | o  f-1: rename h -> i
   | |
   o |  b-1: b update
   |/
   o  i-2: c -move-> d, s -move-> t
   |
   o  i-1: a -move-> c, p -move-> s
   |
   o  i-0 initial commit: a b h p q r
   
   $ hg status --copies --rev 'desc("i-0")' --rev 'desc("mBFm-0")'
   M b
   A d
     h
   A t
     p
   R a
   R h
   R p
   $ hg status --copies --rev 'desc("i-0")' --rev 'desc("mFBm-0")'
   M b
   A d
     h
   A t
     p
   R a
   R h
   R p
   $ hg status --copies --rev 'desc("b-1")' --rev 'desc("mBFm-0")'
   M d (no-changeset !)
     h (no-filelog no-changeset !)
   R h
   $ hg status --copies --rev 'desc("f-2")' --rev 'desc("mBFm-0")'
   M b
   $ hg status --copies --rev 'desc("f-1")' --rev 'desc("mBFm-0")'
   M b
   M d (no-changeset !)
     i (no-filelog no-changeset !)
   R i
   $ hg status --copies --rev 'desc("b-1")' --rev 'desc("mFBm-0")'
   M d (no-changeset !)
     h (no-filelog no-changeset !)
   R h
   $ hg status --copies --rev 'desc("f-2")' --rev 'desc("mFBm-0")'
   M b
   $ hg status --copies --rev 'desc("f-1")' --rev 'desc("mFBm-0")'
   M b
   M d (no-changeset !)
     i (no-filelog no-changeset !)
   R i
 
 #if no-changeset
   $ hg log -Gfr 'desc("mBFm-0")' d
   o  f-2: rename i -> d
   |
   o  f-1: rename h -> i
   :
   o  i-0 initial commit: a b h p q r
   
 #else
 BROKEN: `hg log --follow <file>` relies on filelog metadata to work
   $ hg log -Gfr 'desc("mBFm-0")' d
   o  i-2: c -move-> d, s -move-> t
   |
   ~
 #endif
 
 #if no-changeset
   $ hg log -Gfr 'desc("mFBm-0")' d
   o  f-2: rename i -> d
   |
   o  f-1: rename h -> i
   :
   o  i-0 initial commit: a b h p q r
   
 #else
 BROKEN: `hg log --follow <file>` relies on filelog metadata to work
   $ hg log -Gfr 'desc("mFBm-0")' d
   o  i-2: c -move-> d, s -move-> t
   |
   ~
 #endif
 
 
 Subcase: existing copy information overwritten on one branch, with different content)
 `````````````````````````````````````````````````````````````````````````````````````
 
 Merge:
 - one with change to an unrelated file (b)
 - one overwriting a file (t) with a rename (from r to x to t), v content is not the same as on the other branch
 
   $ hg log -G --rev '::(desc("mBRm")+desc("mRBm"))'
   o    mRBm-0 simple merge - B side: unrelated change, R side: overwrite d with a copy (from r->x->t) different content - the other way
   |\
   +---o  mBRm-0 simple merge - B side: unrelated change, R side: overwrite d with a copy (from r->x->t) different content - one way
   | |/
   | o  r-2: rename t -> x
   | |
   | o  r-1: rename r -> x
   | |
   o |  b-1: b update
   |/
   o  i-2: c -move-> d, s -move-> t
   |
   o  i-1: a -move-> c, p -move-> s
   |
   o  i-0 initial commit: a b h p q r
   
   $ hg status --copies --rev 'desc("i-0")' --rev 'desc("mBRm-0")'
   M b
   A d
     a
   A t
     r
   R a
   R p
   R r
   $ hg status --copies --rev 'desc("i-0")' --rev 'desc("mRBm-0")'
   M b
   A d
     a
   A t
     r
   R a
   R p
   R r
   $ hg status --copies --rev 'desc("b-1")' --rev 'desc("mBRm-0")'
   M t
     r (no-filelog !)
   R r
   $ hg status --copies --rev 'desc("r-2")' --rev 'desc("mBRm-0")'
   M b
   $ hg status --copies --rev 'desc("r-1")' --rev 'desc("mBRm-0")'
   M b
   M t
     x (no-filelog !)
   R x
   $ hg status --copies --rev 'desc("b-1")' --rev 'desc("mRBm-0")'
   M t
     r (no-filelog !)
   R r
   $ hg status --copies --rev 'desc("r-2")' --rev 'desc("mRBm-0")'
   M b
   $ hg status --copies --rev 'desc("r-1")' --rev 'desc("mRBm-0")'
   M b
   M t
     x (no-filelog !)
   R x
 
 #if no-changeset
   $ hg log -Gfr 'desc("mBRm-0")' d
   o  i-2: c -move-> d, s -move-> t
   |
   o  i-1: a -move-> c, p -move-> s
   |
   o  i-0 initial commit: a b h p q r
   
 #else
 BROKEN: `hg log --follow <file>` relies on filelog metadata to work
   $ hg log -Gfr 'desc("mBRm-0")' d
   o  i-2: c -move-> d, s -move-> t
   |
   ~
 #endif
 
 #if no-changeset
   $ hg log -Gfr 'desc("mRBm-0")' d
   o  i-2: c -move-> d, s -move-> t
   |
   o  i-1: a -move-> c, p -move-> s
   |
   o  i-0 initial commit: a b h p q r
   
 #else
 BROKEN: `hg log --follow <file>` relies on filelog metadata to work
   $ hg log -Gfr 'desc("mRBm-0")' d
   o  i-2: c -move-> d, s -move-> t
   |
   ~
 #endif
 
 Subcase: reset of the copy history on one side
 ``````````````````````````````````````````````
 
 Merge:
 - one with change to a file
 - one deleting and recreating the file
 
 Unlike in the 'BD/DB' cases, an actual merge happened here. So we should
 consider history and rename on both branch of the merge.
 
   $ hg log -G --rev '::(desc("mDGm")+desc("mGDm"))'
   o    mGDm-0 actual content merge, copies on one side - D side: delete and re-add (different content), G side: update content - the other way
   |\
   +---o  mDGm-0 actual content merge, copies on one side - D side: delete and re-add (different content), G side: update content - one way
   | |/
   | o  g-1: update d
   | |
   o |  d-2 re-add d
   | |
   o |  d-1 delete d
   |/
   o  i-2: c -move-> d, s -move-> t
   |
   o  i-1: a -move-> c, p -move-> s
   |
   o  i-0 initial commit: a b h p q r
   
 One side of the merge have a long history with rename. The other side of the
 merge point to a new file with a smaller history. Each side is "valid".
 
 (and again the filelog based algorithm only explore one, with a pick based on
 revision numbers)
 
   $ hg status --copies --rev 'desc("i-0")' --rev 'desc("mDGm-0")'
   A d
     a (filelog !)
   A t
     p
   R a
   R p
   $ hg status --copies --rev 'desc("i-0")' --rev 'desc("mGDm-0")'
   A d
     a
   A t
     p
   R a
   R p
   $ hg status --copies --rev 'desc("d-2")' --rev 'desc("mDGm-0")'
   M d
   $ hg status --copies --rev 'desc("d-2")' --rev 'desc("mGDm-0")'
   M d
   $ hg status --copies --rev 'desc("g-1")' --rev 'desc("mDGm-0")'
   M d
   $ hg status --copies --rev 'desc("g-1")' --rev 'desc("mGDm-0")'
   M d
 
 #if no-changeset
   $ hg log -Gfr 'desc("mDGm-0")' d
   o    mDGm-0 actual content merge, copies on one side - D side: delete and re-add (different content), G side: update content - one way
   |\
   | o  g-1: update d
   | |
   o |  d-2 re-add d
   |/
   o  i-2: c -move-> d, s -move-> t
   |
   o  i-1: a -move-> c, p -move-> s
   |
   o  i-0 initial commit: a b h p q r
   
 #else
 BROKEN: `hg log --follow <file>` relies on filelog metadata to work
   $ hg log -Gfr 'desc("mDGm-0")' d
   o    mDGm-0 actual content merge, copies on one side - D side: delete and re-add (different content), G side: update content - one way
   |\
   | o  g-1: update d
   | |
   o |  d-2 re-add d
   |/
   o  i-2: c -move-> d, s -move-> t
   |
   ~
 #endif
 
 
 #if no-changeset
   $ hg log -Gfr 'desc("mDGm-0")' d
   o    mDGm-0 actual content merge, copies on one side - D side: delete and re-add (different content), G side: update content - one way
   |\
   | o  g-1: update d
   | |
   o |  d-2 re-add d
   |/
   o  i-2: c -move-> d, s -move-> t
   |
   o  i-1: a -move-> c, p -move-> s
   |
   o  i-0 initial commit: a b h p q r
   
 #else
 BROKEN: `hg log --follow <file>` relies on filelog metadata to work
   $ hg log -Gfr 'desc("mDGm-0")' d
   o    mDGm-0 actual content merge, copies on one side - D side: delete and re-add (different content), G side: update content - one way
   |\
   | o  g-1: update d
   | |
   o |  d-2 re-add d
   |/
   o  i-2: c -move-> d, s -move-> t
   |
   ~
 #endif
 
 Subcase: merging a change to a file with a "copy overwrite" to that file from another branch
 ````````````````````````````````````````````````````````````````````````````````````````````
 
 Merge:
 - one with change to a file (d)
 - one overwriting that file with a rename (from h to i, to d)
 
 This case is similar to BF/FB, but an actual merge happens, so both side of the
 history are relevant.
 
 
   $ hg log -G --rev '::(desc("mGFm")+desc("mFGm"))'
   o    mGFm-0 merge - G side: content change, F side: copy overwrite, no content change - the other way
   |\
   +---o  mFGm-0 merge - G side: content change, F side: copy overwrite, no content change - one way
   | |/
   | o  g-1: update d
   | |
   o |  f-2: rename i -> d
   | |
   o |  f-1: rename h -> i
   |/
   o  i-2: c -move-> d, s -move-> t
   |
   o  i-1: a -move-> c, p -move-> s
   |
   o  i-0 initial commit: a b h p q r
   
 
 Note:
 | In this case, the merge get conflicting information since on one side we have
 | "a -> c -> d". and one the other one we have "h -> i -> d".
 |
 | The current code arbitrarily pick one side depending the ordering of the merged hash:
 
 In this case, the file hash from "f-2" is lower, so it will be `p1` of the resulting filenode its copy tracing information will win (and trace back to "h"):
 
 Details on this hash ordering pick:
 
   $ hg manifest --debug 'desc("g-1")' | egrep 'd$'
   17ec97e605773eb44a117d1136b3849bcdc1924f 644   d (no-changeset !)
   5cce88bf349f7c742bb440f2c53f81db9c294279 644   d (changeset !)
   $ hg status --copies --rev 'desc("i-0")' --rev 'desc("g-1")' d
   A d
     a (no-changeset no-compatibility !)
 
   $ hg manifest --debug 'desc("f-2")' | egrep 'd$'
   7b79e2fe0c8924e0e598a82f048a7b024afa4d96 644   d (no-changeset !)
   ae258f702dfeca05bf9b6a22a97a4b5645570f11 644   d (changeset !)
   $ hg status --copies --rev 'desc("i-0")' --rev 'desc("f-2")' d
   A d
     h (no-changeset no-compatibility !)
 
 Copy tracing data on the resulting merge:
 
   $ hg status --copies --rev 'desc("i-0")' --rev 'desc("mFGm-0")'
   A d
     h (no-filelog !)
     a (filelog !)
   A t
     p
   R a
   R h
   R p
   $ hg status --copies --rev 'desc("i-0")' --rev 'desc("mGFm-0")'
   A d
     a (no-changeset !)
     h (changeset !)
   A t
     p
   R a
   R h
   R p
   $ hg status --copies --rev 'desc("f-2")' --rev 'desc("mFGm-0")'
   M d
   $ hg status --copies --rev 'desc("f-2")' --rev 'desc("mGFm-0")'
   M d
   $ hg status --copies --rev 'desc("f-1")' --rev 'desc("mFGm-0")'
   M d
     i (no-filelog !)
   R i
   $ hg status --copies --rev 'desc("f-1")' --rev 'desc("mGFm-0")'
   M d
     i (no-filelog !)
   R i
   $ hg status --copies --rev 'desc("g-1")' --rev 'desc("mFGm-0")'
   M d (no-changeset !)
     h (no-filelog no-changeset !)
   R h
   $ hg status --copies --rev 'desc("g-1")' --rev 'desc("mGFm-0")'
   M d (no-changeset !)
     h (no-filelog no-changeset !)
   R h
 
 #if no-changeset
   $ hg log -Gfr 'desc("mFGm-0")' d
   o    mFGm-0 merge - G side: content change, F side: copy overwrite, no content change - one way
   |\
   | o  g-1: update d
   | |
   o |  f-2: rename i -> d
   | |
   o |  f-1: rename h -> i
   |/
   o  i-2: c -move-> d, s -move-> t
   |
   o  i-1: a -move-> c, p -move-> s
   |
   o  i-0 initial commit: a b h p q r
   
 #else
 BROKEN: `hg log --follow <file>` relies on filelog metadata to work
   $ hg log -Gfr 'desc("mFGm-0")' d
   o  g-1: update d
   |
   o  i-2: c -move-> d, s -move-> t
   |
   ~
 #endif
 
 #if no-changeset
   $ hg log -Gfr 'desc("mGFm-0")' d
   o    mGFm-0 merge - G side: content change, F side: copy overwrite, no content change - the other way
   |\
   | o  g-1: update d
   | |
   o |  f-2: rename i -> d
   | |
   o |  f-1: rename h -> i
   |/
   o  i-2: c -move-> d, s -move-> t
   |
   o  i-1: a -move-> c, p -move-> s
   |
   o  i-0 initial commit: a b h p q r
   
 #else
 BROKEN: `hg log --follow <file>` relies on filelog metadata to work
   $ hg log -Gfr 'desc("mGFm-0")' d
   o  g-1: update d
   |
   o  i-2: c -move-> d, s -move-> t
   |
   ~
 #endif
 
 Subcase: new copy information on both side with an actual merge happening
 `````````````````````````````````````````````````````````````````````````
 
 - the "p-" branch renaming 't' to 'v' (through 'u')
 - the "q-" branch renaming 'r' to 'v' (through 'w')
 
 
   $ hg log -G --rev '::(desc("mPQm")+desc("mQPm"))'
   o    mQPm-0 merge with copies info on both side - P side: rename t to v, Q side: r to v, (different content) - the other way
   |\
   +---o  mPQm-0 merge with copies info on both side - P side: rename t to v, Q side: r to v, (different content) - one way
   | |/
   | o  q-2 w -move-> v
   | |
   | o  q-1 r -move-> w
   | |
   o |  p-2: u -move-> v
   | |
   o |  p-1: t -move-> u
   |/
   o  i-2: c -move-> d, s -move-> t
   |
   o  i-1: a -move-> c, p -move-> s
   |
   o  i-0 initial commit: a b h p q r
   
 
 #if no-changeset
   $ hg manifest --debug --rev 'desc("mPQm-0")' | grep '644   v'
   0946c662ef16e4e67397fd717389eb6693d41749 644   v
   $ hg manifest --debug --rev 'desc("mQPm-0")' | grep '644   v'
   0db3aad7fcc1ec27fab57060e327b9e864ea0cc9 644   v
   $ hg manifest --debug --rev 'desc("p-2")' | grep '644   v'
   3f91841cd75cadc9a1f1b4e7c1aa6d411f76032e 644   v
   $ hg manifest --debug --rev 'desc("q-2")' | grep '644   v'
   c43c088b811fd27983c0a9aadf44f3343cd4cd7e 644   v
   $ hg debugindex v | "$PYTHON" ../no-linkrev
      rev linkrev nodeid       p1           p2
        0       * 3f91841cd75c 000000000000 000000000000
        1       * c43c088b811f 000000000000 000000000000
        2       * 0946c662ef16 3f91841cd75c c43c088b811f
        3       * 0db3aad7fcc1 c43c088b811f 3f91841cd75c
 #else
   $ hg manifest --debug --rev 'desc("mPQm-0")' | grep '644   v'
   65fde9f6e4d4da23b3f610e07b53673ea9541d75 644   v
   $ hg manifest --debug --rev 'desc("mQPm-0")' | grep '644   v'
   a098dda6413aecf154eefc976afc38b295acb7e5 644   v
   $ hg manifest --debug --rev 'desc("p-2")' | grep '644   v'
   5aed6a8dbff0301328c08360d24354d3d064cf0d 644   v
   $ hg manifest --debug --rev 'desc("q-2")' | grep '644   v'
   a38b2fa170219750dac9bc7d19df831f213ba708 644   v
   $ hg debugindex v | "$PYTHON" ../no-linkrev
      rev linkrev nodeid       p1           p2
        0       * 5aed6a8dbff0 000000000000 000000000000
        1       * a38b2fa17021 000000000000 000000000000
        2       * 65fde9f6e4d4 5aed6a8dbff0 a38b2fa17021
        3       * a098dda6413a a38b2fa17021 5aed6a8dbff0
 #endif
 
 # Here the filelog based implementation is not looking at the rename
 # information (because the file exist on both side). However the changelog
 # based on works fine. We have different output.
 
   $ hg status --copies --rev 'desc("p-2")' --rev 'desc("mPQm-0")'
   M v
     r (no-filelog !)
   R r
   $ hg status --copies --rev 'desc("p-2")' --rev 'desc("mQPm-0")'
   M v
     r (no-filelog !)
   R r
   $ hg status --copies --rev 'desc("q-2")' --rev 'desc("mPQm-0")'
   M v
     t (no-filelog !)
   R t
   $ hg status --copies --rev 'desc("q-2")' --rev 'desc("mQPm-0")'
   M v
     t (no-filelog !)
   R t
   $ hg status --copies --rev 'desc("i-2")' --rev 'desc("p-2")'
   A v
     t
   R t
   $ hg status --copies --rev 'desc("i-2")' --rev 'desc("q-2")'
   A v
     r
   R r
 
 # From here, we run status against revision where both source file exists.
 #
 # The filelog based implementation picks an arbitrary side based on revision
 # numbers. So the same side "wins" whatever the parents order is. This is
 # sub-optimal because depending on revision numbers means the result can be
 # different from one repository to the next.
 #
 # The changeset based algorithm use the parent order to break tie on conflicting
 # information and will have a different order depending on who is p1 and p2.
 # That order is stable accross repositories. (data from p1 prevails)
 
   $ hg status --copies --rev 'desc("i-2")' --rev 'desc("mPQm-0")'
   A v
     t
   R r
   R t
   $ hg status --copies --rev 'desc("i-2")' --rev 'desc("mQPm-0")'
   A v
     t (filelog !)
     r (no-filelog !)
   R r
   R t
   $ hg status --copies --rev 'desc("i-0")' --rev 'desc("mPQm-0")'
   A d
     a
   A v
     r (filelog !)
     p (no-filelog !)
   R a
   R p
   R r
   $ hg status --copies --rev 'desc("i-0")' --rev 'desc("mQPm-0")'
   A d
     a
   A v
     r
   R a
   R p
   R r
 
 
 Comparing with merging with a deletion (and keeping the file)
 -------------------------------------------------------------
 
 Merge:
 - one removing a file (d)
 - one updating that file
 - the merge keep the modified version of the file (canceling the delete)
 
 In this case, the file keep on living after the merge. So we should not drop its
 copy tracing chain.
 
   $ hg log -G --rev '::(desc("mCGm")+desc("mGCm"))'
   o    mGCm-0 merge updated/deleted - revive the file (updated content) - the other way
   |\
   +---o  mCGm-0 merge updated/deleted - revive the file (updated content) - one way
   | |/
   | o  g-1: update d
   | |
   o |  c-1 delete d
   |/
   o  i-2: c -move-> d, s -move-> t
   |
   o  i-1: a -move-> c, p -move-> s
   |
   o  i-0 initial commit: a b h p q r
   
 
 'a' is the copy source of 'd'
 
   $ hg status --copies --rev 'desc("i-0")' --rev 'desc("mCGm-0")'
   A d
     a (no-compatibility no-changeset !)
   A t
     p
   R a
   R p
   $ hg status --copies --rev 'desc("i-0")' --rev 'desc("mGCm-0")'
   A d
     a (no-compatibility no-changeset !)
   A t
     p
   R a
   R p
   $ hg status --copies --rev 'desc("c-1")' --rev 'desc("mCGm-0")'
   A d
   $ hg status --copies --rev 'desc("c-1")' --rev 'desc("mGCm-0")'
   A d
   $ hg status --copies --rev 'desc("g-1")' --rev 'desc("mCGm-0")'
   $ hg status --copies --rev 'desc("g-1")' --rev 'desc("mGCm-0")'
 
 
 Comparing with merge restoring an untouched deleted file
 --------------------------------------------------------
 
 Merge:
 - one removing a file (d)
 - one leaving the file untouched
 - the merge actively restore the file to the same content.
 
 In this case, the file keep on living after the merge. So we should not drop its
 copy tracing chain.
 
   $ hg log -G --rev '::(desc("mCB-revert-m")+desc("mBC-revert-m"))'
   o    mBC-revert-m-0 merge explicitely revive deleted file - B side: unrelated change, C side: delete d (restored by merge) - the other way
   |\
   +---o  mCB-revert-m-0 merge explicitely revive deleted file - B side: unrelated change, C side: delete d (restored by merge) - one way
   | |/
   | o  c-1 delete d
   | |
   o |  b-1: b update
   |/
   o  i-2: c -move-> d, s -move-> t
   |
   o  i-1: a -move-> c, p -move-> s
   |
   o  i-0 initial commit: a b h p q r
   
 
 'a' is the the copy source of 'd'
 
   $ hg status --copies --rev 'desc("i-0")' --rev 'desc("mCB-revert-m-0")'
   M b
   A d
     a (no-compatibility no-changeset !)
   A t
     p
   R a
   R p
   $ hg status --copies --rev 'desc("i-0")' --rev 'desc("mBC-revert-m-0")'
   M b
   A d
     a (no-compatibility no-changeset !)
   A t
     p
   R a
   R p
   $ hg status --copies --rev 'desc("c-1")' --rev 'desc("mCB-revert-m-0")'
   M b
   A d
   $ hg status --copies --rev 'desc("c-1")' --rev 'desc("mBC-revert-m-0")'
   M b
   A d
   $ hg status --copies --rev 'desc("b-1")' --rev 'desc("mCB-revert-m-0")'
   $ hg status --copies --rev 'desc("b-1")' --rev 'desc("mBC-revert-m-0")'
 
 
 Merging a branch where a rename was deleted with a branch where the same file was renamed
 ------------------------------------------------------------------------------------------
 
 Create a "conflicting" merge where `d` get removed on one branch before its
 rename information actually conflict with the other branch.
 
 (the copy information from the branch that was not deleted should win).
 
   $ hg log -G --rev '::(desc("mCH-delete-before-conflict-m")+desc("mHC-delete-before-conflict-m"))'
   o    mHC-delete-before-conflict-m-0 simple merge - C side: d is the results of renames then deleted, H side: d is result of another rename (same content as the other branch) - the other way
   |\
   +---o  mCH-delete-before-conflict-m-0 simple merge - C side: d is the results of renames then deleted, H side: d is result of another rename (same content as the other branch) - one way
   | |/
   | o  h-1: b -(move)-> d
   | |
   o |  c-1 delete d
   | |
   o |  i-2: c -move-> d, s -move-> t
   | |
   o |  i-1: a -move-> c, p -move-> s
   |/
   o  i-0 initial commit: a b h p q r
   
 
   $ hg status --copies --rev 'desc("i-0")' --rev 'desc("mCH-delete-before-conflict-m")'
   A d
     b (no-compatibility no-changeset !)
   A t
     p
   R a
   R b
   R p
   $ hg status --copies --rev 'desc("i-0")' --rev 'desc("mHC-delete-before-conflict-m")'
   A d
     b
   A t
     p
   R a
   R b
   R p
   $ hg status --copies --rev 'desc("c-1")' --rev 'desc("mCH-delete-before-conflict-m")'
   A d
     b
   R b
   $ hg status --copies --rev 'desc("c-1")' --rev 'desc("mHC-delete-before-conflict-m")'
   A d
     b
   R b
   $ hg status --copies --rev 'desc("h-1")' --rev 'desc("mCH-delete-before-conflict-m")'
   A t
     p
   R a
   R p
   $ hg status --copies --rev 'desc("h-1")' --rev 'desc("mHC-delete-before-conflict-m")'
   A t
     p
   R a
   R p
 
 Variant of previous with extra changes introduced by the merge
 --------------------------------------------------------------
 
 (see case declaration for details)
 
 Subcase: merge has same initial content on both side, but merge introduced a change
 ```````````````````````````````````````````````````````````````````````````````````
 
 - the "e-" branch renaming b to f (through 'g')
 - the "a-" branch renaming d to f (through e)
 - the merge add new change to b
 
   $ hg log -G --rev '::(desc("mAE-change-m")+desc("mEA-change-m"))'
   o    mEA-change-m-0 merge with file update and copies info on both side - A side: rename d to f, E side: b to f, (same content for f in parent) - the other way
   |\
   +---o  mAE-change-m-0 merge with file update and copies info on both side - A side: rename d to f, E side: b to f, (same content for f in parent) - one way
   | |/
   | o  e-2 g -move-> f
   | |
   | o  e-1 b -move-> g
   | |
   o |  a-2: e -move-> f
   | |
   o |  a-1: d -move-> e
   |/
   o  i-2: c -move-> d, s -move-> t
   |
   o  i-1: a -move-> c, p -move-> s
   |
   o  i-0 initial commit: a b h p q r
   
 #if no-changeset
   $ hg manifest --debug --rev 'desc("mAE-change-m-0")' | grep '644   f'
   2f649fba7eb284e720d02b61f0546fcef694c045 644   f
   $ hg manifest --debug --rev 'desc("mEA-change-m-0")' | grep '644   f'
   774e7c1637d536b99e2d8ef16fd731f87a82bd09 644   f
   $ hg manifest --debug --rev 'desc("a-2")' | grep '644   f'
   b76eb76580df486c3d51d63c5c210d4dd43a8ac7 644   f
   $ hg manifest --debug --rev 'desc("e-2")' | grep '644   f'
   e8825b386367b29fec957283a80bb47b47483fe1 644   f
   $ hg debugindex f | "$PYTHON" ../no-linkrev
      rev linkrev nodeid       p1           p2
        0       * b76eb76580df 000000000000 000000000000
        1       * e8825b386367 000000000000 000000000000
        2       * 2ff93c643948 b76eb76580df e8825b386367
        3       * 2f649fba7eb2 b76eb76580df e8825b386367
        4       * 774e7c1637d5 e8825b386367 b76eb76580df
 #else
   $ hg manifest --debug --rev 'desc("mAE-change-m-0")' | grep '644   f'
   d3613c1ec8310a812ac4268fd853ac576b6caea5 644   f
   $ hg manifest --debug --rev 'desc("mEA-change-m-0")' | grep '644   f'
   05e03c868bbcab4a649cb33a238d7aa07398a469 644   f
   $ hg manifest --debug --rev 'desc("a-2")' | grep '644   f'
   ae258f702dfeca05bf9b6a22a97a4b5645570f11 644   f
   $ hg manifest --debug --rev 'desc("e-2")' | grep '644   f'
   ae258f702dfeca05bf9b6a22a97a4b5645570f11 644   f
   $ hg debugindex f | "$PYTHON" ../no-linkrev
      rev linkrev nodeid       p1           p2
        0       * ae258f702dfe 000000000000 000000000000
        1       * d3613c1ec831 ae258f702dfe 000000000000
        2       * 05e03c868bbc ae258f702dfe 000000000000
 #endif
 
 # Here the filelog based implementation is not looking at the rename
 # information (because the file exist on both side). However the changelog
 # based on works fine. We have different output.
 
   $ hg status --copies --rev 'desc("a-2")' --rev 'desc("mAE-change-m-0")'
   M f
     b (no-filelog !)
   R b
   $ hg status --copies --rev 'desc("a-2")' --rev 'desc("mEA-change-m-0")'
   M f
     b (no-filelog !)
   R b
   $ hg status --copies --rev 'desc("e-2")' --rev 'desc("mAE-change-m-0")'
   M f
     d (no-filelog !)
   R d
   $ hg status --copies --rev 'desc("e-2")' --rev 'desc("mEA-change-m-0")'
   M f
     d (no-filelog !)
   R d
   $ hg status --copies --rev 'desc("i-2")' --rev 'desc("a-2")'
   A f
     d
   R d
   $ hg status --copies --rev 'desc("i-2")' --rev 'desc("e-2")'
   A f
     b
   R b
 
 # From here, we run status against revision where both source file exists.
 #
 # The filelog based implementation picks an arbitrary side based on revision
 # numbers. So the same side "wins" whatever the parents order is. This is
 # sub-optimal because depending on revision numbers means the result can be
 # different from one repository to the next.
 #
 # The changeset based algorithm use the parent order to break tie on conflicting
 # information and will have a different order depending on who is p1 and p2.
 # That order is stable accross repositories. (data from p1 prevails)
 
   $ hg status --copies --rev 'desc("i-2")' --rev 'desc("mAE-change-m-0")'
   A f
     d
   R b
   R d
   $ hg status --copies --rev 'desc("i-2")' --rev 'desc("mEA-change-m-0")'
   A f
     d (filelog !)
     b (no-filelog !)
   R b
   R d
   $ hg status --copies --rev 'desc("i-0")' --rev 'desc("mAE-change-m-0")'
   A f
     a
   A t
     p
   R a
   R b
   R p
   $ hg status --copies --rev 'desc("i-0")' --rev 'desc("mEA-change-m-0")'
   A f
     a (filelog !)
     b (no-filelog !)
   A t
     p
   R a
   R b
   R p
 
 
 Subcase: merge overwrite common copy information, but with extra change during the merge
 ```````````````````````````````````````````````````````````````````````````````````
 
 Merge:
 - one with change to an unrelated file (b)
 - one overwriting a file (d) with a rename (from h to i to d)
 
   $ hg log -G --rev '::(desc("mBF-change-m")+desc("mFB-change-m"))'
   o    mFB-change-m-0 merge with extra change - B side: unrelated change, F side: overwrite d with a copy (from h->i->d) - the other way
   |\
   +---o  mBF-change-m-0 merge with extra change - B side: unrelated change, F side: overwrite d with a copy (from h->i->d) - one way
   | |/
   | o  f-2: rename i -> d
   | |
   | o  f-1: rename h -> i
   | |
   o |  b-1: b update
   |/
   o  i-2: c -move-> d, s -move-> t
   |
   o  i-1: a -move-> c, p -move-> s
   |
   o  i-0 initial commit: a b h p q r
   
   $ hg status --copies --rev 'desc("i-0")' --rev 'desc("mBF-change-m-0")'
   M b
   A d
     h
   A t
     p
   R a
   R h
   R p
   $ hg status --copies --rev 'desc("i-0")' --rev 'desc("mFB-change-m-0")'
   M b
   A d
     h
   A t
     p
   R a
   R h
   R p
   $ hg status --copies --rev 'desc("b-1")' --rev 'desc("mBF-change-m-0")'
   M d
     h (no-filelog !)
   R h
   $ hg status --copies --rev 'desc("f-2")' --rev 'desc("mBF-change-m-0")'
   M b
   M d
   $ hg status --copies --rev 'desc("f-1")' --rev 'desc("mBF-change-m-0")'
   M b
   M d
     i (no-filelog !)
   R i
   $ hg status --copies --rev 'desc("b-1")' --rev 'desc("mFB-change-m-0")'
   M d
     h (no-filelog !)
   R h
   $ hg status --copies --rev 'desc("f-2")' --rev 'desc("mFB-change-m-0")'
   M b
   M d
   $ hg status --copies --rev 'desc("f-1")' --rev 'desc("mFB-change-m-0")'
   M b
   M d
     i (no-filelog !)
   R i
 
 #if no-changeset
   $ hg log -Gfr 'desc("mBF-change-m-0")' d
   o    mBF-change-m-0 merge with extra change - B side: unrelated change, F side: overwrite d with a copy (from h->i->d) - one way
   |\
   o :  f-2: rename i -> d
   | :
   o :  f-1: rename h -> i
   :/
   o  i-0 initial commit: a b h p q r
   
 #else
 BROKEN: `hg log --follow <file>` relies on filelog metadata to work
   $ hg log -Gfr 'desc("mBF-change-m-0")' d
   o  mBF-change-m-0 merge with extra change - B side: unrelated change, F side: overwrite d with a copy (from h->i->d) - one way
   :
   o  i-2: c -move-> d, s -move-> t
   |
   ~
 #endif
 
 #if no-changeset
   $ hg log -Gfr 'desc("mFB-change-m-0")' d
   o    mFB-change-m-0 merge with extra change - B side: unrelated change, F side: overwrite d with a copy (from h->i->d) - the other way
   |\
   o :  f-2: rename i -> d
   | :
   o :  f-1: rename h -> i
   :/
   o  i-0 initial commit: a b h p q r
   
 #else
 BROKEN: `hg log --follow <file>` relies on filelog metadata to work
   $ hg log -Gfr 'desc("mFB-change-m-0")' d
   o  mFB-change-m-0 merge with extra change - B side: unrelated change, F side: overwrite d with a copy (from h->i->d) - the other way
   :
   o  i-2: c -move-> d, s -move-> t
   |
   ~
 #endif
 
 
 Subcase: restoring and untouched deleted file, while touching it
 ````````````````````````````````````````````````````````````````
 
 Merge:
 - one removing a file (d)
 - one leaving the file untouched
 - the merge actively restore the file to the same content.
 
 In this case, the file keep on living after the merge. So we should not drop its
 copy tracing chain.
 
   $ hg log -G --rev '::(desc("mCB-change-m")+desc("mBC-change-m"))'
   o    mBC-change-m-0 merge explicitely revive deleted file - B side: unrelated change, C side: delete d (restored by merge) - the other way
   |\
   +---o  mCB-change-m-0 merge explicitely revive deleted file - B side: unrelated change, C side: delete d (restored by merge) - one way
   | |/
   | o  c-1 delete d
   | |
   o |  b-1: b update
   |/
   o  i-2: c -move-> d, s -move-> t
   |
   o  i-1: a -move-> c, p -move-> s
   |
   o  i-0 initial commit: a b h p q r
   
 
 'a' is the the copy source of 'd'
 
   $ hg status --copies --rev 'desc("i-0")' --rev 'desc("mCB-change-m-0")'
   M b
   A d
     a (no-compatibility no-changeset !)
   A t
     p
   R a
   R p
   $ hg status --copies --rev 'desc("i-0")' --rev 'desc("mBC-change-m-0")'
   M b
   A d
     a (no-compatibility no-changeset !)
   A t
     p
   R a
   R p
   $ hg status --copies --rev 'desc("c-1")' --rev 'desc("mCB-change-m-0")'
   M b
   A d
   $ hg status --copies --rev 'desc("c-1")' --rev 'desc("mBC-change-m-0")'
   M b
   A d
   $ hg status --copies --rev 'desc("b-1")' --rev 'desc("mCB-change-m-0")'
   M d
   $ hg status --copies --rev 'desc("b-1")' --rev 'desc("mBC-change-m-0")'
   M d
 
 
 Decision from previous merge are properly chained with later merge
 ------------------------------------------------------------------
 
 
 Subcase: chaining conflicting rename resolution
 ```````````````````````````````````````````````
 
 The "mAEm" and "mEAm" case create a rename tracking conflict on file 'f'. We
 add more change on the respective branch and merge again. These second merge
 does not involve the file 'f' and the arbitration done within "mAEm" and "mEA"
 about that file should stay unchanged.
 
 The result from mAEm is the same for the subsequent merge:
 
   $ hg status --copies --rev 'desc("i-0")' --rev 'desc("mAEm")' f
   A f
     a (no-changeset no-compatibility !)
 
   $ hg status --copies --rev 'desc("i-0")' --rev 'desc("mAE,Km")' f
   A f
     a (no-changeset no-compatibility !)
 
   $ hg status --copies --rev 'desc("i-0")' --rev 'desc("mK,AEm")' f
   A f
     a (no-changeset no-compatibility !)
 
 
 The result from mEAm is the same for the subsequent merge:
 
   $ hg status --copies --rev 'desc("i-0")' --rev 'desc("mEAm")' f
   A f
     a (filelog !)
     b (no-changeset no-compatibility no-filelog !)
 
   $ hg status --copies --rev 'desc("i-0")' --rev 'desc("mEA,Jm")' f
   A f
     a (filelog !)
     b (no-changeset no-compatibility no-filelog !)
 
   $ hg status --copies --rev 'desc("i-0")' --rev 'desc("mJ,EAm")' f
   A f
     a (filelog !)
     b (no-changeset no-compatibility no-filelog !)
 
 Subcase: chaining conflicting rename resolution
 ```````````````````````````````````````````````
 
 The "mPQm" and "mQPm" case create a rename tracking conflict on file 'v'. We
 add more change on the respective branch and merge again. These second merge
 does not involve the file 'v' and the arbitration done within "mPQm" and "mQP"
 about that file should stay unchanged.
 
 The result from mPQm is the same for the subsequent merge:
 
   $ hg status --copies --rev 'desc("i-0")' --rev 'desc("mPQm")' v
   A v
     r (filelog !)
     p (no-changeset no-compatibility no-filelog !)
 
   $ hg status --copies --rev 'desc("i-0")' --rev 'desc("mPQ,Tm")' v
   A v
     r (filelog !)
     p (no-changeset no-compatibility no-filelog !)
 
   $ hg status --copies --rev 'desc("i-0")' --rev 'desc("mT,PQm")' v
   A v
     r (filelog !)
     p (no-changeset no-compatibility no-filelog !)
 
 The result from mQPm is the same for the subsequent merge:
 
   $ hg status --copies --rev 'desc("i-0")' --rev 'desc("mQPm")' v
   A v
     r (no-changeset no-compatibility !)
 
   $ hg status --copies --rev 'desc("i-0")' --rev 'desc("mQP,Sm")' v
   A v
     r (no-changeset no-compatibility !)
 
   $ hg status --copies --rev 'desc("i-0")' --rev 'desc("mS,QPm")' v
   A v
     r (filelog !)
     r (no-changeset no-compatibility no-filelog !)
 
 
 Subcase: chaining salvage information during a merge
 ````````````````````````````````````````````````````
 
 We add more change on the branch were the file was deleted. merging again
 should preserve the fact eh file was salvaged.
 
 reference output:
 
   $ hg status --copies --rev 'desc("i-0")' --rev 'desc("mCB-revert-m-0")'
   M b
   A d
     a (no-changeset no-compatibility !)
   A t
     p
   R a
   R p
   $ hg status --copies --rev 'desc("i-0")' --rev 'desc("mBC-revert-m-0")'
   M b
   A d
     a (no-changeset no-compatibility !)
   A t
     p
   R a
   R p
 
 chained output
   $ hg status --copies --rev 'desc("i-0")' --rev 'desc("mBC+revert,Lm")'
   M b
   A d
     a (no-changeset no-compatibility !)
   A t
     p
   A unrelated-l
   R a
   R p
   $ hg status --copies --rev 'desc("i-0")' --rev 'desc("mCB+revert,Lm")'
   M b
   A d
     a (no-changeset no-compatibility !)
   A t
     p
   A unrelated-l
   R a
   R p
   $ hg status --copies --rev 'desc("i-0")' --rev 'desc("mL,BC+revertm")'
   M b
   A d
     a (no-changeset no-compatibility !)
   A t
     p
   A unrelated-l
   R a
   R p
   $ hg status --copies --rev 'desc("i-0")' --rev 'desc("mL,CB+revertm")'
   M b
   A d
     a (no-changeset no-compatibility !)
   A t
     p
   A unrelated-l
   R a
   R p
 
 Subcase: chaining "merged" information during a merge
 ``````````````````````````````````````````````````````
 
 When a non-rename change are merged with a copy overwrite, the merge pick the copy source from (p1) as the reference. We should preserve this information in subsequent merges.
 
 
 reference output:
 
  (for details about the filelog pick, check the mFGm/mGFm case)
 
   $ hg status --copies --rev 'desc("i-0")' --rev 'desc("mFGm")' d
   A d
     a (filelog !)
     h (no-changeset no-compatibility no-filelog !)
   $ hg status --copies --rev 'desc("i-0")' --rev 'desc("mGFm")' d
   A d
     a (filelog !)
     a (no-changeset no-compatibility no-filelog !)
 
 Chained output
 
   $ hg status --copies --rev 'desc("i-0")' --rev 'desc("mO,FGm")' d
   A d
     a (filelog !)
     h (no-changeset no-compatibility no-filelog !)
   $ hg status --copies --rev 'desc("i-0")' --rev 'desc("mFG,Om")' d
   A d
     a (filelog !)
     h (no-changeset no-compatibility no-filelog !)
 
 
   $ hg status --copies --rev 'desc("i-0")' --rev 'desc("mGF,Nm")' d
   A d
     a (no-changeset no-compatibility !)
   $ hg status --copies --rev 'desc("i-0")' --rev 'desc("mN,GFm")' d
   A d
     a (no-changeset no-compatibility !)
 
 
 Subcase: chaining conflicting rename resolution, with extra change during the merge
 ```````````````````````````````````````````````````````````````````````````````````
 
 The "mAEm" and "mEAm" case create a rename tracking conflict on file 'f'. We
 add more change on the respective branch and merge again. These second merge
 does not involve the file 'f' and the arbitration done within "mAEm" and "mEA"
 about that file should stay unchanged.
 
 The result from mAEm is the same for the subsequent merge:
 
   $ hg status --copies --rev 'desc("i-0")' --rev 'desc("mAE-change-m")' f
   A f
     a (no-changeset no-compatibility !)
 
   $ hg status --copies --rev 'desc("i-0")' --rev 'desc("mAE-change,Km")' f
   A f
     a (no-changeset no-compatibility !)
 
   $ hg status --copies --rev 'desc("i-0")' --rev 'desc("mK,AE-change-m")' f
   A f
     a (no-changeset no-compatibility !)
 
 
 The result from mEAm is the same for the subsequent merge:
 
   $ hg status --copies --rev 'desc("i-0")' --rev 'desc("mEA-change-m")' f
   A f
     a (filelog !)
     b (no-changeset no-compatibility no-filelog !)
 
   $ hg status --copies --rev 'desc("i-0")' --rev 'desc("mEA-change,Jm")' f
   A f
     a (filelog !)
     b (no-changeset no-compatibility no-filelog !)
 
   $ hg status --copies --rev 'desc("i-0")' --rev 'desc("mJ,EA-change-m")' f
   A f
     a (filelog !)
     b (no-changeset no-compatibility no-filelog !)

tests/test-copies-in-changeset.t

@@ -1,492 +1,488 b''
 #testcases extra sidedata
 
 #if extra
   $ cat >> $HGRCPATH << EOF
   > [experimental]
   > copies.write-to=changeset-only
   > copies.read-from=changeset-only
   > [alias]
   > changesetcopies = log -r . -T 'files: {files}
   >   {extras % "{ifcontains("files", key, "{key}: {value}\n")}"}
   >   {extras % "{ifcontains("copies", key, "{key}: {value}\n")}"}'
   > EOF
 #endif
 
 #if sidedata
   $ cat >> $HGRCPATH << EOF
   > [format]
   > exp-use-copies-side-data-changeset = yes
   > EOF
 #endif
 
   $ cat >> $HGRCPATH << EOF
   > [alias]
   > showcopies = log -r . -T '{file_copies % "{source} -> {name}\n"}'
   > [extensions]
   > rebase =
   > split =
   > EOF
 
 Check that copies are recorded correctly
 
   $ hg init repo
   $ cd repo
 #if sidedata
   $ hg debugformat -v | egrep 'format-variant|revlog-v2|copies-sdc|changelog-v2'
   format-variant     repo config default
   copies-sdc:         yes    yes      no
   revlog-v2:           no     no      no
   changelog-v2:       yes    yes      no
 #else
   $ hg debugformat -v | egrep 'format-variant|revlog-v2|copies-sdc|changelog-v2'
   format-variant     repo config default
   copies-sdc:          no     no      no
   revlog-v2:           no     no      no
   changelog-v2:        no     no      no
 #endif
   $ echo a > a
   $ hg add a
   $ hg ci -m initial
   $ hg cp a b
   $ hg cp a c
   $ hg cp a d
   $ hg ci -m 'copy a to b, c, and d'
 
 #if extra
 
   $ hg changesetcopies
   files: b c d
   filesadded: 0
   1
   2
   
   p1copies: 0\x00a (esc)
   1\x00a (esc)
   2\x00a (esc)
 #else
   $ hg debugsidedata -c -v -- -1
   1 sidedata entries
    entry-0014 size 44
     '\x00\x00\x00\x04\x00\x00\x00\x00\x01\x00\x00\x00\x00\x06\x00\x00\x00\x02\x00\x00\x00\x00\x06\x00\x00\x00\x03\x00\x00\x00\x00\x06\x00\x00\x00\x04\x00\x00\x00\x00abcd'
 #endif
 
   $ hg showcopies
   a -> b
   a -> c
   a -> d
 
 #if extra
 
   $ hg showcopies --config experimental.copies.read-from=compatibility
   a -> b
   a -> c
   a -> d
   $ hg showcopies --config experimental.copies.read-from=filelog-only
 
 #endif
 
 Check that renames are recorded correctly
 
   $ hg mv b b2
   $ hg ci -m 'rename b to b2'
 
 #if extra
 
   $ hg changesetcopies
   files: b b2
   filesadded: 1
   filesremoved: 0
   
   p1copies: 1\x00b (esc)
 
 #else
   $ hg debugsidedata -c -v -- -1
   1 sidedata entries
    entry-0014 size 25
     '\x00\x00\x00\x02\x0c\x00\x00\x00\x01\x00\x00\x00\x00\x06\x00\x00\x00\x03\x00\x00\x00\x00bb2'
 #endif
 
   $ hg showcopies
   b -> b2
 
 
 Rename onto existing file. This should get recorded in the changeset files list and in the extras,
 even though there is no filelog entry.
 
   $ hg cp b2 c --force
   $ hg st --copies
   M c
     b2
 
 #if extra
 
   $ hg debugindex c
      rev linkrev nodeid       p1           p2
        0       1 b789fdd96dc2 000000000000 000000000000
 
 #else
 
   $ hg debugindex c
      rev linkrev nodeid       p1           p2
        0       1 37d9b5d994ea 000000000000 000000000000
 
 #endif
 
 
   $ hg ci -m 'move b onto d'
 
 #if extra
 
   $ hg changesetcopies
   files: c
   
   p1copies: 0\x00b2 (esc)
 
 #else
   $ hg debugsidedata -c -v -- -1
   1 sidedata entries
    entry-0014 size 25
     '\x00\x00\x00\x02\x00\x00\x00\x00\x02\x00\x00\x00\x00\x16\x00\x00\x00\x03\x00\x00\x00\x00b2c'
 #endif
 
   $ hg showcopies
   b2 -> c
 
 #if extra
 
   $ hg debugindex c
      rev linkrev nodeid       p1           p2
        0       1 b789fdd96dc2 000000000000 000000000000
 
 #else
 
   $ hg debugindex c
      rev linkrev nodeid       p1           p2
        0       1 37d9b5d994ea 000000000000 000000000000
        1       3 029625640347 000000000000 000000000000
 
 #endif
 
 Create a merge commit with copying done during merge.
 
   $ hg co 0
   0 files updated, 0 files merged, 3 files removed, 0 files unresolved
   $ hg cp a e
   $ hg cp a f
   $ hg ci -m 'copy a to e and f'
   created new head
   $ hg merge 3
   3 files updated, 0 files merged, 0 files removed, 0 files unresolved
   (branch merge, don't forget to commit)
 File 'a' exists on both sides, so 'g' could be recorded as being from p1 or p2, but we currently
 always record it as being from p1
   $ hg cp a g
 File 'd' exists only in p2, so 'h' should be from p2
   $ hg cp d h
 File 'f' exists only in p1, so 'i' should be from p1
   $ hg cp f i
   $ hg ci -m 'merge'
 
 #if extra
 
   $ hg changesetcopies
   files: g h i
   filesadded: 0
   1
   2
   
   p1copies: 0\x00a (esc)
   2\x00f (esc)
   p2copies: 1\x00d (esc)
 
 #else
   $ hg debugsidedata -c -v -- -1
   1 sidedata entries
    entry-0014 size 64
     '\x00\x00\x00\x06\x00\x00\x00\x00\x01\x00\x00\x00\x00\x00\x00\x00\x00\x02\x00\x00\x00\x00\x00\x00\x00\x00\x03\x00\x00\x00\x00\x06\x00\x00\x00\x04\x00\x00\x00\x00\x07\x00\x00\x00\x05\x00\x00\x00\x01\x06\x00\x00\x00\x06\x00\x00\x00\x02adfghi'
 #endif
 
   $ hg showcopies
   a -> g
   d -> h
   f -> i
 
 Test writing to both changeset and filelog
 
   $ hg cp a j
 #if extra
   $ hg ci -m 'copy a to j' --config experimental.copies.write-to=compatibility
   $ hg changesetcopies
   files: j
   filesadded: 0
   filesremoved: 
   
   p1copies: 0\x00a (esc)
   p2copies: 
 #else
   $ hg ci -m 'copy a to j'
   $ hg debugsidedata -c -v -- -1
   1 sidedata entries
    entry-0014 size 24
     '\x00\x00\x00\x02\x00\x00\x00\x00\x01\x00\x00\x00\x00\x06\x00\x00\x00\x02\x00\x00\x00\x00aj'
 #endif
   $ hg debugdata j 0
   \x01 (esc)
   copy: a
   copyrev: b789fdd96dc2f3bd229c1dd8eedf0fc60e2b68e3
   \x01 (esc)
   a
   $ hg showcopies
   a -> j
   $ hg showcopies --config experimental.copies.read-from=compatibility
   a -> j
   $ hg showcopies --config experimental.copies.read-from=filelog-only
   a -> j
 Existing copy information in the changeset gets removed on amend and writing
 copy information on to the filelog
 #if extra
   $ hg ci --amend -m 'copy a to j, v2' \
   > --config experimental.copies.write-to=filelog-only
   saved backup bundle to $TESTTMP/repo/.hg/strip-backup/*-*-amend.hg (glob)
   $ hg changesetcopies
   files: j
   
 #else
   $ hg ci --amend -m 'copy a to j, v2'
   saved backup bundle to $TESTTMP/repo/.hg/strip-backup/*-*-amend.hg (glob)
   $ hg debugsidedata -c -v -- -1
   1 sidedata entries
    entry-0014 size 24
     '\x00\x00\x00\x02\x00\x00\x00\x00\x01\x00\x00\x00\x00\x06\x00\x00\x00\x02\x00\x00\x00\x00aj'
 #endif
   $ hg showcopies --config experimental.copies.read-from=filelog-only
   a -> j
 The entries should be written to extras even if they're empty (so the client
 won't have to fall back to reading from filelogs)
   $ echo x >> j
 #if extra
   $ hg ci -m 'modify j' --config experimental.copies.write-to=compatibility
   $ hg changesetcopies
   files: j
   filesadded: 
   filesremoved: 
   
   p1copies: 
   p2copies: 
 #else
   $ hg ci -m 'modify j'
   $ hg debugsidedata -c -v -- -1
   1 sidedata entries
    entry-0014 size 14
     '\x00\x00\x00\x01\x14\x00\x00\x00\x01\x00\x00\x00\x00j'
 #endif
 
 Test writing only to filelog
 
   $ hg cp a k
 #if extra
   $ hg ci -m 'copy a to k' --config experimental.copies.write-to=filelog-only
 
   $ hg changesetcopies
   files: k
   
 #else
   $ hg ci -m 'copy a to k'
   $ hg debugsidedata -c -v -- -1
   1 sidedata entries
    entry-0014 size 24
     '\x00\x00\x00\x02\x00\x00\x00\x00\x01\x00\x00\x00\x00\x06\x00\x00\x00\x02\x00\x00\x00\x00ak'
 #endif
 
   $ hg debugdata k 0
   \x01 (esc)
   copy: a
   copyrev: b789fdd96dc2f3bd229c1dd8eedf0fc60e2b68e3
   \x01 (esc)
   a
 #if extra
   $ hg showcopies
 
   $ hg showcopies --config experimental.copies.read-from=compatibility
   a -> k
   $ hg showcopies --config experimental.copies.read-from=filelog-only
   a -> k
 #else
   $ hg showcopies
   a -> k
 #endif
 
 Existing copy information is preserved by amend
   $ hg cp a l
   $ hg ci -m 'copy a to l'
   $ hg showcopies
   a -> l
   $ hg ci --amend -m 'new description'
   saved backup bundle to $TESTTMP/repo/.hg/strip-backup/*-*-amend.hg (glob)
   $ hg showcopies
   a -> l
 
 No crash on partial amend
   $ hg st --change .
   A l
   $ echo modified >> a
   $ hg rm l
   $ hg commit --amend a
   saved backup bundle to $TESTTMP/repo/.hg/strip-backup/*-*-amend.hg (glob)
 
   $ cd ..
 
 Test rebasing a commit with copy information
 
   $ hg init rebase-rename
   $ cd rebase-rename
   $ echo a > a
   $ hg ci -Aqm 'add a'
   $ echo a2 > a
   $ hg ci -m 'modify a'
   $ hg co -q 0
   $ hg mv a b
   $ hg ci -qm 'rename a to b'
 Not only do we want this to run in-memory, it shouldn't fall back to
 on-disk merge (no conflicts), so we force it to be in-memory
 with no fallback.
   $ hg rebase -d 1 --config rebase.experimental.inmemory=yes --config devel.rebase.force-in-memory-merge=yes
   rebasing 2:* tip "rename a to b" (glob)
   merging a and b to b
   saved backup bundle to $TESTTMP/rebase-rename/.hg/strip-backup/*-*-rebase.hg (glob)
   $ hg st --change . --copies
   A b
     a
   R a
   $ cd ..
 
 Test splitting a commit
 
   $ hg init split
   $ cd split
   $ echo a > a
   $ echo b > b
   $ hg ci -Aqm 'add a and b'
   $ echo a2 > a
   $ hg mv b c
   $ hg ci -m 'modify a, move b to c'
   $ hg --config ui.interactive=yes split <<EOF
   > y
   > y
   > n
   > y
   > EOF
   diff --git a/a b/a
   1 hunks, 1 lines changed
   examine changes to 'a'?
   (enter ? for help) [Ynesfdaq?] y
   
   @@ -1,1 +1,1 @@
   -a
   +a2
   record this change to 'a'?
   (enter ? for help) [Ynesfdaq?] y
   
   diff --git a/b b/c
   rename from b
   rename to c
   examine changes to 'b' and 'c'?
   (enter ? for help) [Ynesfdaq?] n
   
   created new head
   diff --git a/b b/c
   rename from b
   rename to c
   examine changes to 'b' and 'c'?
   (enter ? for help) [Ynesfdaq?] y
   
   saved backup bundle to $TESTTMP/split/.hg/strip-backup/*-*-split.hg (glob)
   $ cd ..
 
 Test committing half a rename
 
   $ hg init partial
   $ cd partial
   $ echo a > a
   $ hg ci -Aqm 'add a'
   $ hg mv a b
   $ hg ci -m 'remove a' a
 
 #if sidedata
 
 Test upgrading/downgrading to sidedata storage
 ==============================================
 
 downgrading
 
   $ hg debugformat -v | egrep 'format-variant|revlog-v2|copies-sdc|changelog-v2'
   format-variant     repo config default
   copies-sdc:         yes    yes      no
   revlog-v2:           no     no      no
   changelog-v2:       yes    yes      no
   $ hg debugsidedata -c -- 0
   1 sidedata entries
    entry-0014 size 14
   $ hg debugsidedata -c -- 1
   1 sidedata entries
    entry-0014 size 14
   $ hg debugsidedata -m -- 0
   $ cat << EOF > .hg/hgrc
   > [format]
   > exp-use-copies-side-data-changeset = no
   > EOF
   $ hg debugupgraderepo --run --quiet --no-backup
   upgrade will perform the following actions:
   
   requirements
      preserved: * (glob)
      removed: exp-changelog-v2, exp-copies-sidedata-changeset
   
   processed revlogs:
-    - all-filelogs
     - changelog
-    - manifest
   
   $ hg debugformat -v | egrep 'format-variant|revlog-v2|copies-sdc|changelog-v2'
   format-variant     repo config default
   copies-sdc:          no     no      no
   revlog-v2:           no     no      no
   changelog-v2:        no     no      no
   $ hg debugsidedata -c -- 0
   $ hg debugsidedata -c -- 1
   $ hg debugsidedata -m -- 0
 
 upgrading
 
   $ cat << EOF > .hg/hgrc
   > [format]
   > exp-use-copies-side-data-changeset = yes
   > EOF
   $ hg debugupgraderepo --run --quiet --no-backup
   upgrade will perform the following actions:
   
   requirements
      preserved: * (glob)
      added: exp-changelog-v2, exp-copies-sidedata-changeset
   
   processed revlogs:
-    - all-filelogs
     - changelog
-    - manifest
   
   $ hg debugformat -v | egrep 'format-variant|revlog-v2|copies-sdc|changelog-v2'
   format-variant     repo config default
   copies-sdc:         yes    yes      no
   revlog-v2:           no     no      no
   changelog-v2:       yes    yes      no
   $ hg debugsidedata -c -- 0
   1 sidedata entries
    entry-0014 size 14
   $ hg debugsidedata -c -- 1
   1 sidedata entries
    entry-0014 size 14
   $ hg debugsidedata -m -- 0
 
 #endif
 
   $ cd ..