dirstate-v2: fix upgrade on an empty repository

This used to crash as the dirstate file does not exist in this case.

Differential Revision: https://phab.mercurial-scm.org/D11866

mercurial/upgrade_utils/engine.py

@@ -1,648 +1,662 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 __future__ import absolute_import
 
+import errno
 import stat
 
 from ..i18n import _
 from ..pycompat import getattr
 from .. import (
     changelog,
     error,
     filelog,
     manifest,
     metadata,
     pycompat,
     requirements,
     scmutil,
     store,
     util,
     vfs as vfsmod,
 )
 from ..revlogutils import (
     constants as revlogconst,
     flagutil,
     nodemap,
     sidedata as sidedatamod,
 )
 from . import actions as upgrade_actions
 
 
 def get_sidedata_helpers(srcrepo, dstrepo):
     use_w = srcrepo.ui.configbool(b'experimental', b'worker.repository-upgrade')
     sequential = pycompat.iswindows or not use_w
     if not sequential:
         srcrepo.register_sidedata_computer(
             revlogconst.KIND_CHANGELOG,
             sidedatamod.SD_FILES,
             (sidedatamod.SD_FILES,),
             metadata._get_worker_sidedata_adder(srcrepo, dstrepo),
             flagutil.REVIDX_HASCOPIESINFO,
             replace=True,
         )
     return sidedatamod.get_sidedata_helpers(srcrepo, dstrepo._wanted_sidedata)
 
 
 def _revlogfrompath(repo, rl_type, path):
     """Obtain a revlog from a repo path.
 
     An instance of the appropriate class is returned.
     """
     if rl_type & store.FILEFLAGS_CHANGELOG:
         return changelog.changelog(repo.svfs)
     elif rl_type & store.FILEFLAGS_MANIFESTLOG:
         mandir = b''
         if b'/' in path:
             mandir = path.rsplit(b'/', 1)[0]
         return manifest.manifestrevlog(
             repo.nodeconstants, repo.svfs, tree=mandir
         )
     else:
         # drop the extension and the `data/` prefix
         path_part = path.rsplit(b'.', 1)[0].split(b'/', 1)
         if len(path_part) < 2:
             msg = _(b'cannot recognize revlog from filename: %s')
             msg %= path
             raise error.Abort(msg)
         path = path_part[1]
         return filelog.filelog(repo.svfs, path)
 
 
 def _copyrevlog(tr, destrepo, oldrl, rl_type, unencodedname):
     """copy all relevant files for `oldrl` into `destrepo` store
 
     Files are copied "as is" without any transformation. The copy is performed
     without extra checks. Callers are responsible for making sure the copied
     content is compatible with format of the destination repository.
     """
     oldrl = getattr(oldrl, '_revlog', oldrl)
     newrl = _revlogfrompath(destrepo, rl_type, unencodedname)
     newrl = getattr(newrl, '_revlog', newrl)
 
     oldvfs = oldrl.opener
     newvfs = newrl.opener
     oldindex = oldvfs.join(oldrl._indexfile)
     newindex = newvfs.join(newrl._indexfile)
     olddata = oldvfs.join(oldrl._datafile)
     newdata = newvfs.join(newrl._datafile)
 
     with newvfs(newrl._indexfile, b'w'):
         pass  # create all the directories
 
     util.copyfile(oldindex, newindex)
     copydata = oldrl.opener.exists(oldrl._datafile)
     if copydata:
         util.copyfile(olddata, newdata)
 
     if rl_type & store.FILEFLAGS_FILELOG:
         destrepo.svfs.fncache.add(unencodedname)
         if copydata:
             destrepo.svfs.fncache.add(unencodedname[:-2] + b'.d')
 
 
 UPGRADE_CHANGELOG = b"changelog"
 UPGRADE_MANIFEST = b"manifest"
 UPGRADE_FILELOGS = b"all-filelogs"
 
 UPGRADE_ALL_REVLOGS = frozenset(
     [UPGRADE_CHANGELOG, UPGRADE_MANIFEST, UPGRADE_FILELOGS]
 )
 
 
 def matchrevlog(revlogfilter, rl_type):
     """check if a revlog is selected for cloning.
 
     In other words, are there any updates which need to be done on revlog
     or it can be blindly copied.
 
     The store entry is checked against the passed filter"""
     if rl_type & store.FILEFLAGS_CHANGELOG:
         return UPGRADE_CHANGELOG in revlogfilter
     elif rl_type & store.FILEFLAGS_MANIFESTLOG:
         return UPGRADE_MANIFEST in revlogfilter
     assert rl_type & store.FILEFLAGS_FILELOG
     return UPGRADE_FILELOGS in revlogfilter
 
 
 def _perform_clone(
     ui,
     dstrepo,
     tr,
     old_revlog,
     rl_type,
     unencoded,
     upgrade_op,
     sidedata_helpers,
     oncopiedrevision,
 ):
     """returns the new revlog object created"""
     newrl = None
     if matchrevlog(upgrade_op.revlogs_to_process, rl_type):
         ui.note(
             _(b'cloning %d revisions from %s\n') % (len(old_revlog), unencoded)
         )
         newrl = _revlogfrompath(dstrepo, rl_type, unencoded)
         old_revlog.clone(
             tr,
             newrl,
             addrevisioncb=oncopiedrevision,
             deltareuse=upgrade_op.delta_reuse_mode,
             forcedeltabothparents=upgrade_op.force_re_delta_both_parents,
             sidedata_helpers=sidedata_helpers,
         )
     else:
         msg = _(b'blindly copying %s containing %i revisions\n')
         ui.note(msg % (unencoded, len(old_revlog)))
         _copyrevlog(tr, dstrepo, old_revlog, rl_type, unencoded)
 
         newrl = _revlogfrompath(dstrepo, rl_type, unencoded)
     return newrl
 
 
 def _clonerevlogs(
     ui,
     srcrepo,
     dstrepo,
     tr,
     upgrade_op,
 ):
     """Copy revlogs between 2 repos."""
     revcount = 0
     srcsize = 0
     srcrawsize = 0
     dstsize = 0
     fcount = 0
     frevcount = 0
     fsrcsize = 0
     frawsize = 0
     fdstsize = 0
     mcount = 0
     mrevcount = 0
     msrcsize = 0
     mrawsize = 0
     mdstsize = 0
     crevcount = 0
     csrcsize = 0
     crawsize = 0
     cdstsize = 0
 
     alldatafiles = list(srcrepo.store.walk())
     # mapping of data files which needs to be cloned
     # key is unencoded filename
     # value is revlog_object_from_srcrepo
     manifests = {}
     changelogs = {}
     filelogs = {}
 
     # Perform a pass to collect metadata. This validates we can open all
     # source files and allows a unified progress bar to be displayed.
     for rl_type, unencoded, size in alldatafiles:
         if not rl_type & store.FILEFLAGS_REVLOG_MAIN:
             continue
 
         # the store.walk function will wrongly pickup transaction backup and
         # get confused. As a quick fix for 5.9 release, we ignore those.
         # (this is not a module constants because it seems better to keep the
         # hack together)
         skip_undo = (
             b'undo.backup.00changelog.i',
             b'undo.backup.00manifest.i',
         )
         if unencoded in skip_undo:
             continue
 
         rl = _revlogfrompath(srcrepo, rl_type, unencoded)
 
         info = rl.storageinfo(
             exclusivefiles=True,
             revisionscount=True,
             trackedsize=True,
             storedsize=True,
         )
 
         revcount += info[b'revisionscount'] or 0
         datasize = info[b'storedsize'] or 0
         rawsize = info[b'trackedsize'] or 0
 
         srcsize += datasize
         srcrawsize += rawsize
 
         # This is for the separate progress bars.
         if rl_type & store.FILEFLAGS_CHANGELOG:
             changelogs[unencoded] = (rl_type, rl)
             crevcount += len(rl)
             csrcsize += datasize
             crawsize += rawsize
         elif rl_type & store.FILEFLAGS_MANIFESTLOG:
             manifests[unencoded] = (rl_type, rl)
             mcount += 1
             mrevcount += len(rl)
             msrcsize += datasize
             mrawsize += rawsize
         elif rl_type & store.FILEFLAGS_FILELOG:
             filelogs[unencoded] = (rl_type, rl)
             fcount += 1
             frevcount += len(rl)
             fsrcsize += datasize
             frawsize += rawsize
         else:
             error.ProgrammingError(b'unknown revlog type')
 
     if not revcount:
         return
 
     ui.status(
         _(
             b'migrating %d total revisions (%d in filelogs, %d in manifests, '
             b'%d in changelog)\n'
         )
         % (revcount, frevcount, mrevcount, crevcount)
     )
     ui.status(
         _(b'migrating %s in store; %s tracked data\n')
         % ((util.bytecount(srcsize), util.bytecount(srcrawsize)))
     )
 
     # Used to keep track of progress.
     progress = None
 
     def oncopiedrevision(rl, rev, node):
         progress.increment()
 
     sidedata_helpers = get_sidedata_helpers(srcrepo, dstrepo)
 
     # Migrating filelogs
     ui.status(
         _(
             b'migrating %d filelogs containing %d revisions '
             b'(%s in store; %s tracked data)\n'
         )
         % (
             fcount,
             frevcount,
             util.bytecount(fsrcsize),
             util.bytecount(frawsize),
         )
     )
     progress = srcrepo.ui.makeprogress(_(b'file revisions'), total=frevcount)
     for unencoded, (rl_type, oldrl) in sorted(filelogs.items()):
         newrl = _perform_clone(
             ui,
             dstrepo,
             tr,
             oldrl,
             rl_type,
             unencoded,
             upgrade_op,
             sidedata_helpers,
             oncopiedrevision,
         )
         info = newrl.storageinfo(storedsize=True)
         fdstsize += info[b'storedsize'] or 0
     ui.status(
         _(
             b'finished migrating %d filelog revisions across %d '
             b'filelogs; change in size: %s\n'
         )
         % (frevcount, fcount, util.bytecount(fdstsize - fsrcsize))
     )
 
     # Migrating manifests
     ui.status(
         _(
             b'migrating %d manifests containing %d revisions '
             b'(%s in store; %s tracked data)\n'
         )
         % (
             mcount,
             mrevcount,
             util.bytecount(msrcsize),
             util.bytecount(mrawsize),
         )
     )
     if progress:
         progress.complete()
     progress = srcrepo.ui.makeprogress(
         _(b'manifest revisions'), total=mrevcount
     )
     for unencoded, (rl_type, oldrl) in sorted(manifests.items()):
         newrl = _perform_clone(
             ui,
             dstrepo,
             tr,
             oldrl,
             rl_type,
             unencoded,
             upgrade_op,
             sidedata_helpers,
             oncopiedrevision,
         )
         info = newrl.storageinfo(storedsize=True)
         mdstsize += info[b'storedsize'] or 0
     ui.status(
         _(
             b'finished migrating %d manifest revisions across %d '
             b'manifests; change in size: %s\n'
         )
         % (mrevcount, mcount, util.bytecount(mdstsize - msrcsize))
     )
 
     # Migrating changelog
     ui.status(
         _(
             b'migrating changelog containing %d revisions '
             b'(%s in store; %s tracked data)\n'
         )
         % (
             crevcount,
             util.bytecount(csrcsize),
             util.bytecount(crawsize),
         )
     )
     if progress:
         progress.complete()
     progress = srcrepo.ui.makeprogress(
         _(b'changelog revisions'), total=crevcount
     )
     for unencoded, (rl_type, oldrl) in sorted(changelogs.items()):
         newrl = _perform_clone(
             ui,
             dstrepo,
             tr,
             oldrl,
             rl_type,
             unencoded,
             upgrade_op,
             sidedata_helpers,
             oncopiedrevision,
         )
         info = newrl.storageinfo(storedsize=True)
         cdstsize += info[b'storedsize'] or 0
     progress.complete()
     ui.status(
         _(
             b'finished migrating %d changelog revisions; change in size: '
             b'%s\n'
         )
         % (crevcount, util.bytecount(cdstsize - csrcsize))
     )
 
     dstsize = fdstsize + mdstsize + cdstsize
     ui.status(
         _(
             b'finished migrating %d total revisions; total change in store '
             b'size: %s\n'
         )
         % (revcount, util.bytecount(dstsize - srcsize))
     )
 
 
 def _files_to_copy_post_revlog_clone(srcrepo):
     """yields files which should be copied to destination after revlogs
     are cloned"""
     for path, kind, st in sorted(srcrepo.store.vfs.readdir(b'', stat=True)):
         # don't copy revlogs as they are already cloned
         if store.revlog_type(path) is not None:
             continue
         # Skip transaction related files.
         if path.startswith(b'undo'):
             continue
         # Only copy regular files.
         if kind != stat.S_IFREG:
             continue
         # Skip other skipped files.
         if path in (b'lock', b'fncache'):
             continue
         # TODO: should we skip cache too?
 
         yield path
 
 
 def _replacestores(currentrepo, upgradedrepo, backupvfs, upgrade_op):
     """Replace the stores after current repository is upgraded
 
     Creates a backup of current repository store at backup path
     Replaces upgraded store files in current repo from upgraded one
 
     Arguments:
       currentrepo: repo object of current repository
       upgradedrepo: repo object of the upgraded data
       backupvfs: vfs object for the backup path
       upgrade_op: upgrade operation object
                   to be used to decide what all is upgraded
     """
     # TODO: don't blindly rename everything in store
     # There can be upgrades where store is not touched at all
     if upgrade_op.backup_store:
         util.rename(currentrepo.spath, backupvfs.join(b'store'))
     else:
         currentrepo.vfs.rmtree(b'store', forcibly=True)
     util.rename(upgradedrepo.spath, currentrepo.spath)
 
 
 def finishdatamigration(ui, srcrepo, dstrepo, requirements):
     """Hook point for extensions to perform additional actions during upgrade.
 
     This function is called after revlogs and store files have been copied but
     before the new store is swapped into the original location.
     """
 
 
 def upgrade(ui, srcrepo, dstrepo, upgrade_op):
     """Do the low-level work of upgrading a repository.
 
     The upgrade is effectively performed as a copy between a source
     repository and a temporary destination repository.
 
     The source repository is unmodified for as long as possible so the
     upgrade can abort at any time without causing loss of service for
     readers and without corrupting the source repository.
     """
     assert srcrepo.currentwlock()
     assert dstrepo.currentwlock()
     backuppath = None
     backupvfs = None
 
     ui.status(
         _(
             b'(it is safe to interrupt this process any time before '
             b'data migration completes)\n'
         )
     )
 
     if upgrade_actions.dirstatev2 in upgrade_op.upgrade_actions:
         ui.status(_(b'upgrading to dirstate-v2 from v1\n'))
         upgrade_dirstate(ui, srcrepo, upgrade_op, b'v1', b'v2')
         upgrade_op.upgrade_actions.remove(upgrade_actions.dirstatev2)
 
     if upgrade_actions.dirstatev2 in upgrade_op.removed_actions:
         ui.status(_(b'downgrading from dirstate-v2 to v1\n'))
         upgrade_dirstate(ui, srcrepo, upgrade_op, b'v2', b'v1')
         upgrade_op.removed_actions.remove(upgrade_actions.dirstatev2)
 
     if not (upgrade_op.upgrade_actions or upgrade_op.removed_actions):
         return
 
     if upgrade_op.requirements_only:
         ui.status(_(b'upgrading repository requirements\n'))
         scmutil.writereporequirements(srcrepo, upgrade_op.new_requirements)
     # if there is only one action and that is persistent nodemap upgrade
     # directly write the nodemap file and update requirements instead of going
     # through the whole cloning process
     elif (
         len(upgrade_op.upgrade_actions) == 1
         and b'persistent-nodemap' in upgrade_op.upgrade_actions_names
         and not upgrade_op.removed_actions
     ):
         ui.status(
             _(b'upgrading repository to use persistent nodemap feature\n')
         )
         with srcrepo.transaction(b'upgrade') as tr:
             unfi = srcrepo.unfiltered()
             cl = unfi.changelog
             nodemap.persist_nodemap(tr, cl, force=True)
             # we want to directly operate on the underlying revlog to force
             # create a nodemap file. This is fine since this is upgrade code
             # and it heavily relies on repository being revlog based
             # hence accessing private attributes can be justified
             nodemap.persist_nodemap(
                 tr, unfi.manifestlog._rootstore._revlog, force=True
             )
         scmutil.writereporequirements(srcrepo, upgrade_op.new_requirements)
     elif (
         len(upgrade_op.removed_actions) == 1
         and [
             x
             for x in upgrade_op.removed_actions
             if x.name == b'persistent-nodemap'
         ]
         and not upgrade_op.upgrade_actions
     ):
         ui.status(
             _(b'downgrading repository to not use persistent nodemap feature\n')
         )
         with srcrepo.transaction(b'upgrade') as tr:
             unfi = srcrepo.unfiltered()
             cl = unfi.changelog
             nodemap.delete_nodemap(tr, srcrepo, cl)
             # check comment 20 lines above for accessing private attributes
             nodemap.delete_nodemap(
                 tr, srcrepo, unfi.manifestlog._rootstore._revlog
             )
         scmutil.writereporequirements(srcrepo, upgrade_op.new_requirements)
     else:
         with dstrepo.transaction(b'upgrade') as tr:
             _clonerevlogs(
                 ui,
                 srcrepo,
                 dstrepo,
                 tr,
                 upgrade_op,
             )
 
         # Now copy other files in the store directory.
         for p in _files_to_copy_post_revlog_clone(srcrepo):
             srcrepo.ui.status(_(b'copying %s\n') % p)
             src = srcrepo.store.rawvfs.join(p)
             dst = dstrepo.store.rawvfs.join(p)
             util.copyfile(src, dst, copystat=True)
 
         finishdatamigration(ui, srcrepo, dstrepo, requirements)
 
         ui.status(_(b'data fully upgraded in a temporary repository\n'))
 
         if upgrade_op.backup_store:
             backuppath = pycompat.mkdtemp(
                 prefix=b'upgradebackup.', dir=srcrepo.path
             )
             backupvfs = vfsmod.vfs(backuppath)
 
             # Make a backup of requires file first, as it is the first to be modified.
             util.copyfile(
                 srcrepo.vfs.join(b'requires'), backupvfs.join(b'requires')
             )
 
         # We install an arbitrary requirement that clients must not support
         # as a mechanism to lock out new clients during the data swap. This is
         # better than allowing a client to continue while the repository is in
         # an inconsistent state.
         ui.status(
             _(
                 b'marking source repository as being upgraded; clients will be '
                 b'unable to read from repository\n'
             )
         )
         scmutil.writereporequirements(
             srcrepo, srcrepo.requirements | {b'upgradeinprogress'}
         )
 
         ui.status(_(b'starting in-place swap of repository data\n'))
         if upgrade_op.backup_store:
             ui.status(
                 _(b'replaced files will be backed up at %s\n') % backuppath
             )
 
         # Now swap in the new store directory. Doing it as a rename should make
         # the operation nearly instantaneous and atomic (at least in well-behaved
         # environments).
         ui.status(_(b'replacing store...\n'))
         tstart = util.timer()
         _replacestores(srcrepo, dstrepo, backupvfs, upgrade_op)
         elapsed = util.timer() - tstart
         ui.status(
             _(
                 b'store replacement complete; repository was inconsistent for '
                 b'%0.1fs\n'
             )
             % elapsed
         )
 
         # We first write the requirements file. Any new requirements will lock
         # out legacy clients.
         ui.status(
             _(
                 b'finalizing requirements file and making repository readable '
                 b'again\n'
             )
         )
         scmutil.writereporequirements(srcrepo, upgrade_op.new_requirements)
 
         if upgrade_op.backup_store:
             # The lock file from the old store won't be removed because nothing has a
             # reference to its new location. So clean it up manually. Alternatively, we
             # could update srcrepo.svfs and other variables to point to the new
             # location. This is simpler.
             assert backupvfs is not None  # help pytype
             backupvfs.unlink(b'store/lock')
 
     return backuppath
 
 
 def upgrade_dirstate(ui, srcrepo, upgrade_op, old, new):
     if upgrade_op.backup_store:
         backuppath = pycompat.mkdtemp(
             prefix=b'upgradebackup.', dir=srcrepo.path
         )
         ui.status(_(b'replaced files will be backed up at %s\n') % backuppath)
         backupvfs = vfsmod.vfs(backuppath)
         util.copyfile(
             srcrepo.vfs.join(b'requires'), backupvfs.join(b'requires')
         )
-        util.copyfile(
-            srcrepo.vfs.join(b'dirstate'), backupvfs.join(b'dirstate')
-        )
+        try:
+            util.copyfile(
+                srcrepo.vfs.join(b'dirstate'), backupvfs.join(b'dirstate')
+            )
+        except (IOError, OSError) as e:
+            # The dirstate does not exist on an empty repo or a repo with no
+            # revision checked out
+            if e.errno != errno.ENOENT:
+                raise
 
     assert srcrepo.dirstate._use_dirstate_v2 == (old == b'v2')
     srcrepo.dirstate._map.preload()
     srcrepo.dirstate._use_dirstate_v2 = new == b'v2'
     srcrepo.dirstate._map._use_dirstate_v2 = srcrepo.dirstate._use_dirstate_v2
     srcrepo.dirstate._dirty = True
-    srcrepo.vfs.unlink(b'dirstate')
+    try:
+        srcrepo.vfs.unlink(b'dirstate')
+    except (IOError, OSError) as e:
+        # The dirstate does not exist on an empty repo or a repo with no
+        # revision checked out
+        if e.errno != errno.ENOENT:
+            raise
+
     srcrepo.dirstate.write(None)
 
     scmutil.writereporequirements(srcrepo, upgrade_op.new_requirements)

tests/test-upgrade-repo.t

@@ -1,1703 +1,1766 b''
 #require no-reposimplestore
 
   $ cat >> $HGRCPATH << EOF
   > [extensions]
   > share =
   > [format]
   > # stabilize test accross variant
   > revlog-compression=zlib
   > EOF
 
 store and revlogv1 are required in source
 
   $ hg --config format.usestore=false init no-store
   $ hg -R no-store debugupgraderepo
   abort: cannot upgrade repository; requirement missing: store
   [255]
 
   $ hg init no-revlogv1
   $ cat > no-revlogv1/.hg/requires << EOF
   > dotencode
   > fncache
   > generaldelta
   > store
   > EOF
 
   $ hg -R no-revlogv1 debugupgraderepo
   abort: cannot upgrade repository; missing a revlog version
   [255]
 
 Cannot upgrade shared repositories
 
   $ hg init share-parent
   $ hg -q share share-parent share-child
 
   $ hg -R share-child debugupgraderepo
   abort: cannot upgrade repository; unsupported source requirement: shared
   [255]
 
 Do not yet support upgrading treemanifest repos
 
   $ hg --config experimental.treemanifest=true init treemanifest
   $ hg -R treemanifest debugupgraderepo
   abort: cannot upgrade repository; unsupported source requirement: treemanifest
   [255]
 
 Cannot add treemanifest requirement during upgrade
 
   $ hg init disallowaddedreq
   $ hg -R disallowaddedreq --config experimental.treemanifest=true debugupgraderepo
   abort: cannot upgrade repository; do not support adding requirement: treemanifest
   [255]
 
 An upgrade of a repository created with recommended settings only suggests optimizations
 
   $ hg init empty
   $ cd empty
   $ hg debugformat
   format-variant     repo
   fncache:            yes
   dirstate-v2:         no
   dotencode:          yes
   generaldelta:       yes
   share-safe:          no
   sparserevlog:       yes
   persistent-nodemap:  no (no-rust !)
   persistent-nodemap: yes (rust !)
   copies-sdc:          no
   revlog-v2:           no
   changelog-v2:        no
   plain-cl-delta:     yes
   compression:        zlib
   compression-level:  default
   $ hg debugformat --verbose
   format-variant     repo config default
   fncache:            yes    yes     yes
   dirstate-v2:         no     no      no
   dotencode:          yes    yes     yes
   generaldelta:       yes    yes     yes
   share-safe:          no     no      no
   sparserevlog:       yes    yes     yes
   persistent-nodemap:  no     no      no (no-rust !)
   persistent-nodemap: yes    yes      no (rust !)
   copies-sdc:          no     no      no
   revlog-v2:           no     no      no
   changelog-v2:        no     no      no
   plain-cl-delta:     yes    yes     yes
   compression:        zlib   zlib    zlib (no-zstd !)
   compression:        zlib   zlib    zstd (zstd !)
   compression-level:  default default default
   $ hg debugformat --verbose --config format.usefncache=no
   format-variant     repo config default
   fncache:            yes     no     yes
   dirstate-v2:         no     no      no
   dotencode:          yes     no     yes
   generaldelta:       yes    yes     yes
   share-safe:          no     no      no
   sparserevlog:       yes    yes     yes
   persistent-nodemap:  no     no      no (no-rust !)
   persistent-nodemap: yes    yes      no (rust !)
   copies-sdc:          no     no      no
   revlog-v2:           no     no      no
   changelog-v2:        no     no      no
   plain-cl-delta:     yes    yes     yes
   compression:        zlib   zlib    zlib (no-zstd !)
   compression:        zlib   zlib    zstd (zstd !)
   compression-level:  default default default
   $ hg debugformat --verbose --config format.usefncache=no --color=debug
   format-variant     repo config default
   [formatvariant.name.mismatchconfig|fncache:           ][formatvariant.repo.mismatchconfig| yes][formatvariant.config.special|     no][formatvariant.default|     yes]
   [formatvariant.name.uptodate|dirstate-v2:       ][formatvariant.repo.uptodate|  no][formatvariant.config.default|     no][formatvariant.default|      no]
   [formatvariant.name.mismatchconfig|dotencode:         ][formatvariant.repo.mismatchconfig| yes][formatvariant.config.special|     no][formatvariant.default|     yes]
   [formatvariant.name.uptodate|generaldelta:      ][formatvariant.repo.uptodate| yes][formatvariant.config.default|    yes][formatvariant.default|     yes]
   [formatvariant.name.uptodate|share-safe:        ][formatvariant.repo.uptodate|  no][formatvariant.config.default|     no][formatvariant.default|      no]
   [formatvariant.name.uptodate|sparserevlog:      ][formatvariant.repo.uptodate| yes][formatvariant.config.default|    yes][formatvariant.default|     yes]
   [formatvariant.name.uptodate|persistent-nodemap:][formatvariant.repo.uptodate|  no][formatvariant.config.default|     no][formatvariant.default|      no] (no-rust !)
   [formatvariant.name.mismatchdefault|persistent-nodemap:][formatvariant.repo.mismatchdefault| yes][formatvariant.config.special|    yes][formatvariant.default|      no] (rust !)
   [formatvariant.name.uptodate|copies-sdc:        ][formatvariant.repo.uptodate|  no][formatvariant.config.default|     no][formatvariant.default|      no]
   [formatvariant.name.uptodate|revlog-v2:         ][formatvariant.repo.uptodate|  no][formatvariant.config.default|     no][formatvariant.default|      no]
   [formatvariant.name.uptodate|changelog-v2:      ][formatvariant.repo.uptodate|  no][formatvariant.config.default|     no][formatvariant.default|      no]
   [formatvariant.name.uptodate|plain-cl-delta:    ][formatvariant.repo.uptodate| yes][formatvariant.config.default|    yes][formatvariant.default|     yes]
   [formatvariant.name.uptodate|compression:       ][formatvariant.repo.uptodate| zlib][formatvariant.config.default|   zlib][formatvariant.default|    zlib] (no-zstd !)
   [formatvariant.name.mismatchdefault|compression:       ][formatvariant.repo.mismatchdefault| zlib][formatvariant.config.special|   zlib][formatvariant.default|    zstd] (zstd !)
   [formatvariant.name.uptodate|compression-level: ][formatvariant.repo.uptodate| default][formatvariant.config.default| default][formatvariant.default| default]
   $ hg debugformat -Tjson
   [
    {
     "config": true,
     "default": true,
     "name": "fncache",
     "repo": true
    },
    {
     "config": false,
     "default": false,
     "name": "dirstate-v2",
     "repo": false
    },
    {
     "config": true,
     "default": true,
     "name": "dotencode",
     "repo": true
    },
    {
     "config": true,
     "default": true,
     "name": "generaldelta",
     "repo": true
    },
    {
     "config": false,
     "default": false,
     "name": "share-safe",
     "repo": false
    },
    {
     "config": true,
     "default": true,
     "name": "sparserevlog",
     "repo": true
    },
    {
     "config": false, (no-rust !)
     "config": true, (rust !)
     "default": false,
     "name": "persistent-nodemap",
     "repo": false (no-rust !)
     "repo": true (rust !)
    },
    {
     "config": false,
     "default": false,
     "name": "copies-sdc",
     "repo": false
    },
    {
     "config": false,
     "default": false,
     "name": "revlog-v2",
     "repo": false
    },
    {
     "config": false,
     "default": false,
     "name": "changelog-v2",
     "repo": false
    },
    {
     "config": true,
     "default": true,
     "name": "plain-cl-delta",
     "repo": true
    },
    {
     "config": "zlib",
     "default": "zlib", (no-zstd !)
     "default": "zstd", (zstd !)
     "name": "compression",
     "repo": "zlib"
    },
    {
     "config": "default",
     "default": "default",
     "name": "compression-level",
     "repo": "default"
    }
   ]
   $ hg debugupgraderepo
   (no format upgrades found in existing repository)
   performing an upgrade with "--run" will make the following changes:
   
   requirements
      preserved: dotencode, fncache, generaldelta, revlogv1, sparserevlog, store (no-rust !)
      preserved: dotencode, fncache, generaldelta, persistent-nodemap, revlogv1, sparserevlog, store (rust !)
   
   processed revlogs:
     - all-filelogs
     - changelog
     - manifest
   
   additional optimizations are available by specifying "--optimize <name>":
   
   re-delta-parent
      deltas within internal storage will be recalculated to choose an optimal base revision where this was not already done; the size of the repository may shrink and various operations may become faster; the first time this optimization is performed could slow down upgrade execution considerably; subsequent invocations should not run noticeably slower
   
   re-delta-multibase
      deltas within internal storage will be recalculated against multiple base revision and the smallest difference will be used; the size of the repository may shrink significantly when there are many merges; this optimization will slow down execution in proportion to the number of merges in the repository and the amount of files in the repository; this slow down should not be significant unless there are tens of thousands of files and thousands of merges
   
   re-delta-all
      deltas within internal storage will always be recalculated without reusing prior deltas; this will likely make execution run several times slower; this optimization is typically not needed
   
   re-delta-fulladd
      every revision will be re-added as if it was new content. It will go through the full storage mechanism giving extensions a chance to process it (eg. lfs). This is similar to "re-delta-all" but even slower since more logic is involved.
   
 
   $ hg debugupgraderepo --quiet
   requirements
      preserved: dotencode, fncache, generaldelta, revlogv1, sparserevlog, store (no-rust !)
      preserved: dotencode, fncache, generaldelta, persistent-nodemap, revlogv1, sparserevlog, store (rust !)
   
   processed revlogs:
     - all-filelogs
     - changelog
     - manifest
   
 
 --optimize can be used to add optimizations
 
   $ hg debugupgrade --optimize 're-delta-parent'
   (no format upgrades found in existing repository)
   performing an upgrade with "--run" will make the following changes:
   
   requirements
      preserved: dotencode, fncache, generaldelta, revlogv1, sparserevlog, store (no-rust !)
      preserved: dotencode, fncache, generaldelta, persistent-nodemap, revlogv1, sparserevlog, store (rust !)
   
   optimisations: re-delta-parent
   
   re-delta-parent
      deltas within internal storage will choose a new base revision if needed
   
   processed revlogs:
     - all-filelogs
     - changelog
     - manifest
   
   additional optimizations are available by specifying "--optimize <name>":
   
   re-delta-multibase
      deltas within internal storage will be recalculated against multiple base revision and the smallest difference will be used; the size of the repository may shrink significantly when there are many merges; this optimization will slow down execution in proportion to the number of merges in the repository and the amount of files in the repository; this slow down should not be significant unless there are tens of thousands of files and thousands of merges
   
   re-delta-all
      deltas within internal storage will always be recalculated without reusing prior deltas; this will likely make execution run several times slower; this optimization is typically not needed
   
   re-delta-fulladd
      every revision will be re-added as if it was new content. It will go through the full storage mechanism giving extensions a chance to process it (eg. lfs). This is similar to "re-delta-all" but even slower since more logic is involved.
   
 
 modern form of the option
 
   $ hg debugupgrade --optimize re-delta-parent
   (no format upgrades found in existing repository)
   performing an upgrade with "--run" will make the following changes:
   
   requirements
      preserved: dotencode, fncache, generaldelta, revlogv1, sparserevlog, store (no-rust !)
      preserved: dotencode, fncache, generaldelta, persistent-nodemap, revlogv1, sparserevlog, store (rust !)
   
   optimisations: re-delta-parent
   
   re-delta-parent
      deltas within internal storage will choose a new base revision if needed
   
   processed revlogs:
     - all-filelogs
     - changelog
     - manifest
   
   additional optimizations are available by specifying "--optimize <name>":
   
   re-delta-multibase
      deltas within internal storage will be recalculated against multiple base revision and the smallest difference will be used; the size of the repository may shrink significantly when there are many merges; this optimization will slow down execution in proportion to the number of merges in the repository and the amount of files in the repository; this slow down should not be significant unless there are tens of thousands of files and thousands of merges
   
   re-delta-all
      deltas within internal storage will always be recalculated without reusing prior deltas; this will likely make execution run several times slower; this optimization is typically not needed
   
   re-delta-fulladd
      every revision will be re-added as if it was new content. It will go through the full storage mechanism giving extensions a chance to process it (eg. lfs). This is similar to "re-delta-all" but even slower since more logic is involved.
   
   $ hg debugupgrade --optimize re-delta-parent --quiet
   requirements
      preserved: dotencode, fncache, generaldelta, revlogv1, sparserevlog, store (no-rust !)
      preserved: dotencode, fncache, generaldelta, persistent-nodemap, revlogv1, sparserevlog, store (rust !)
   
   optimisations: re-delta-parent
   
   processed revlogs:
     - all-filelogs
     - changelog
     - manifest
   
 
 unknown optimization:
 
   $ hg debugupgrade --optimize foobar
   abort: unknown optimization action requested: foobar
   (run without arguments to see valid optimizations)
   [255]
 
 Various sub-optimal detections work
 
   $ cat > .hg/requires << EOF
   > revlogv1
   > store
   > EOF
 
   $ hg debugformat
   format-variant     repo
   fncache:             no
   dirstate-v2:         no
   dotencode:           no
   generaldelta:        no
   share-safe:          no
   sparserevlog:        no
   persistent-nodemap:  no
   copies-sdc:          no
   revlog-v2:           no
   changelog-v2:        no
   plain-cl-delta:     yes
   compression:        zlib
   compression-level:  default
   $ hg debugformat --verbose
   format-variant     repo config default
   fncache:             no    yes     yes
   dirstate-v2:         no     no      no
   dotencode:           no    yes     yes
   generaldelta:        no    yes     yes
   share-safe:          no     no      no
   sparserevlog:        no    yes     yes
   persistent-nodemap:  no     no      no (no-rust !)
   persistent-nodemap:  no    yes      no (rust !)
   copies-sdc:          no     no      no
   revlog-v2:           no     no      no
   changelog-v2:        no     no      no
   plain-cl-delta:     yes    yes     yes
   compression:        zlib   zlib    zlib (no-zstd !)
   compression:        zlib   zlib    zstd (zstd !)
   compression-level:  default default default
   $ hg debugformat --verbose --config format.usegeneraldelta=no
   format-variant     repo config default
   fncache:             no    yes     yes
   dirstate-v2:         no     no      no
   dotencode:           no    yes     yes
   generaldelta:        no     no     yes
   share-safe:          no     no      no
   sparserevlog:        no     no     yes
   persistent-nodemap:  no     no      no (no-rust !)
   persistent-nodemap:  no    yes      no (rust !)
   copies-sdc:          no     no      no
   revlog-v2:           no     no      no
   changelog-v2:        no     no      no
   plain-cl-delta:     yes    yes     yes
   compression:        zlib   zlib    zlib (no-zstd !)
   compression:        zlib   zlib    zstd (zstd !)
   compression-level:  default default default
   $ hg debugformat --verbose --config format.usegeneraldelta=no --color=debug
   format-variant     repo config default
   [formatvariant.name.mismatchconfig|fncache:           ][formatvariant.repo.mismatchconfig|  no][formatvariant.config.default|    yes][formatvariant.default|     yes]
   [formatvariant.name.uptodate|dirstate-v2:       ][formatvariant.repo.uptodate|  no][formatvariant.config.default|     no][formatvariant.default|      no]
   [formatvariant.name.mismatchconfig|dotencode:         ][formatvariant.repo.mismatchconfig|  no][formatvariant.config.default|    yes][formatvariant.default|     yes]
   [formatvariant.name.mismatchdefault|generaldelta:      ][formatvariant.repo.mismatchdefault|  no][formatvariant.config.special|     no][formatvariant.default|     yes]
   [formatvariant.name.uptodate|share-safe:        ][formatvariant.repo.uptodate|  no][formatvariant.config.default|     no][formatvariant.default|      no]
   [formatvariant.name.mismatchdefault|sparserevlog:      ][formatvariant.repo.mismatchdefault|  no][formatvariant.config.special|     no][formatvariant.default|     yes]
   [formatvariant.name.uptodate|persistent-nodemap:][formatvariant.repo.uptodate|  no][formatvariant.config.default|     no][formatvariant.default|      no] (no-rust !)
   [formatvariant.name.mismatchconfig|persistent-nodemap:][formatvariant.repo.mismatchconfig|  no][formatvariant.config.special|    yes][formatvariant.default|      no] (rust !)
   [formatvariant.name.uptodate|copies-sdc:        ][formatvariant.repo.uptodate|  no][formatvariant.config.default|     no][formatvariant.default|      no]
   [formatvariant.name.uptodate|revlog-v2:         ][formatvariant.repo.uptodate|  no][formatvariant.config.default|     no][formatvariant.default|      no]
   [formatvariant.name.uptodate|changelog-v2:      ][formatvariant.repo.uptodate|  no][formatvariant.config.default|     no][formatvariant.default|      no]
   [formatvariant.name.uptodate|plain-cl-delta:    ][formatvariant.repo.uptodate| yes][formatvariant.config.default|    yes][formatvariant.default|     yes]
   [formatvariant.name.uptodate|compression:       ][formatvariant.repo.uptodate| zlib][formatvariant.config.default|   zlib][formatvariant.default|    zlib] (no-zstd !)
   [formatvariant.name.mismatchdefault|compression:       ][formatvariant.repo.mismatchdefault| zlib][formatvariant.config.special|   zlib][formatvariant.default|    zstd] (zstd !)
   [formatvariant.name.uptodate|compression-level: ][formatvariant.repo.uptodate| default][formatvariant.config.default| default][formatvariant.default| default]
   $ hg debugupgraderepo
   repository lacks features recommended by current config options:
   
   fncache
      long and reserved filenames may not work correctly; repository performance is sub-optimal
   
   dotencode
      storage of filenames beginning with a period or space may not work correctly
   
   generaldelta
      deltas within internal storage are unable to choose optimal revisions; repository is larger and slower than it could be; interaction with other repositories may require extra network and CPU resources, making "hg push" and "hg pull" slower
   
   sparserevlog
      in order to limit disk reading and memory usage on older version, the span of a delta chain from its root to its end is limited, whatever the relevant data in this span. This can severly limit Mercurial ability to build good chain of delta resulting is much more storage space being taken and limit reusability of on disk delta during exchange.
   
   persistent-nodemap (rust !)
      persist the node -> rev mapping on disk to speedup lookup (rust !)
    (rust !)
   
   performing an upgrade with "--run" will make the following changes:
   
   requirements
      preserved: revlogv1, store
      added: dotencode, fncache, generaldelta, sparserevlog (no-rust !)
      added: dotencode, fncache, generaldelta, persistent-nodemap, sparserevlog (rust !)
   
   fncache
      repository will be more resilient to storing certain paths and performance of certain operations should be improved
   
   dotencode
      repository will be better able to store files beginning with a space or period
   
   generaldelta
      repository storage will be able to create optimal deltas; new repository data will be smaller and read times should decrease; interacting with other repositories using this storage model should require less network and CPU resources, making "hg push" and "hg pull" faster
   
   sparserevlog
      Revlog supports delta chain with more unused data between payload. These gaps will be skipped at read time. This allows for better delta chains, making a better compression and faster exchange with server.
   
   persistent-nodemap (rust !)
      Speedup revision lookup by node id. (rust !)
    (rust !)
   processed revlogs:
     - all-filelogs
     - changelog
     - manifest
   
   additional optimizations are available by specifying "--optimize <name>":
   
   re-delta-parent
      deltas within internal storage will be recalculated to choose an optimal base revision where this was not already done; the size of the repository may shrink and various operations may become faster; the first time this optimization is performed could slow down upgrade execution considerably; subsequent invocations should not run noticeably slower
   
   re-delta-multibase
      deltas within internal storage will be recalculated against multiple base revision and the smallest difference will be used; the size of the repository may shrink significantly when there are many merges; this optimization will slow down execution in proportion to the number of merges in the repository and the amount of files in the repository; this slow down should not be significant unless there are tens of thousands of files and thousands of merges
   
   re-delta-all
      deltas within internal storage will always be recalculated without reusing prior deltas; this will likely make execution run several times slower; this optimization is typically not needed
   
   re-delta-fulladd
      every revision will be re-added as if it was new content. It will go through the full storage mechanism giving extensions a chance to process it (eg. lfs). This is similar to "re-delta-all" but even slower since more logic is involved.
   
   $ hg debugupgraderepo --quiet
   requirements
      preserved: revlogv1, store
      added: dotencode, fncache, generaldelta, sparserevlog (no-rust !)
      added: dotencode, fncache, generaldelta, persistent-nodemap, sparserevlog (rust !)
   
   processed revlogs:
     - all-filelogs
     - changelog
     - manifest
   
 
   $ hg --config format.dotencode=false debugupgraderepo
   repository lacks features recommended by current config options:
   
   fncache
      long and reserved filenames may not work correctly; repository performance is sub-optimal
   
   generaldelta
      deltas within internal storage are unable to choose optimal revisions; repository is larger and slower than it could be; interaction with other repositories may require extra network and CPU resources, making "hg push" and "hg pull" slower
   
   sparserevlog
      in order to limit disk reading and memory usage on older version, the span of a delta chain from its root to its end is limited, whatever the relevant data in this span. This can severly limit Mercurial ability to build good chain of delta resulting is much more storage space being taken and limit reusability of on disk delta during exchange.
   
   persistent-nodemap (rust !)
      persist the node -> rev mapping on disk to speedup lookup (rust !)
    (rust !)
   repository lacks features used by the default config options:
   
   dotencode
      storage of filenames beginning with a period or space may not work correctly
   
   
   performing an upgrade with "--run" will make the following changes:
   
   requirements
      preserved: revlogv1, store
      added: fncache, generaldelta, sparserevlog (no-rust !)
      added: fncache, generaldelta, persistent-nodemap, sparserevlog (rust !)
   
   fncache
      repository will be more resilient to storing certain paths and performance of certain operations should be improved
   
   generaldelta
      repository storage will be able to create optimal deltas; new repository data will be smaller and read times should decrease; interacting with other repositories using this storage model should require less network and CPU resources, making "hg push" and "hg pull" faster
   
   sparserevlog
      Revlog supports delta chain with more unused data between payload. These gaps will be skipped at read time. This allows for better delta chains, making a better compression and faster exchange with server.
   
   persistent-nodemap (rust !)
      Speedup revision lookup by node id. (rust !)
    (rust !)
   processed revlogs:
     - all-filelogs
     - changelog
     - manifest
   
   additional optimizations are available by specifying "--optimize <name>":
   
   re-delta-parent
      deltas within internal storage will be recalculated to choose an optimal base revision where this was not already done; the size of the repository may shrink and various operations may become faster; the first time this optimization is performed could slow down upgrade execution considerably; subsequent invocations should not run noticeably slower
   
   re-delta-multibase
      deltas within internal storage will be recalculated against multiple base revision and the smallest difference will be used; the size of the repository may shrink significantly when there are many merges; this optimization will slow down execution in proportion to the number of merges in the repository and the amount of files in the repository; this slow down should not be significant unless there are tens of thousands of files and thousands of merges
   
   re-delta-all
      deltas within internal storage will always be recalculated without reusing prior deltas; this will likely make execution run several times slower; this optimization is typically not needed
   
   re-delta-fulladd
      every revision will be re-added as if it was new content. It will go through the full storage mechanism giving extensions a chance to process it (eg. lfs). This is similar to "re-delta-all" but even slower since more logic is involved.
   
 
   $ cd ..
 
 Upgrading a repository that is already modern essentially no-ops
 
   $ hg init modern
   $ hg -R modern debugupgraderepo --run
   nothing to do
 
 Upgrading a repository to generaldelta works
 
   $ hg --config format.usegeneraldelta=false init upgradegd
   $ cd upgradegd
   $ touch f0
   $ hg -q commit -A -m initial
   $ mkdir FooBarDirectory.d
   $ touch FooBarDirectory.d/f1
   $ hg -q commit -A -m 'add f1'
   $ hg -q up -r 0
   >>> from __future__ import absolute_import, print_function
   >>> import random
   >>> random.seed(0) # have a reproducible content
   >>> with open("f2", "wb") as f:
   ...     for i in range(100000):
   ...         f.write(b"%d\n" % random.randint(1000000000, 9999999999)) and None
   $ hg -q commit -A -m 'add f2'
 
 make sure we have a .d file
 
   $ ls -d .hg/store/data/*
   .hg/store/data/_foo_bar_directory.d.hg
   .hg/store/data/f0.i
   .hg/store/data/f2.d
   .hg/store/data/f2.i
 
   $ hg debugupgraderepo --run --config format.sparse-revlog=false
   upgrade will perform the following actions:
   
   requirements
      preserved: dotencode, fncache, revlogv1, store (no-rust !)
      preserved: dotencode, fncache, persistent-nodemap, revlogv1, store (rust !)
      added: generaldelta
   
   generaldelta
      repository storage will be able to create optimal deltas; new repository data will be smaller and read times should decrease; interacting with other repositories using this storage model should require less network and CPU resources, making "hg push" and "hg pull" faster
   
   processed revlogs:
     - all-filelogs
     - changelog
     - manifest
   
   beginning upgrade...
   repository locked and read-only
   creating temporary repository to stage upgraded data: $TESTTMP/upgradegd/.hg/upgrade.* (glob)
   (it is safe to interrupt this process any time before data migration completes)
   migrating 9 total revisions (3 in filelogs, 3 in manifests, 3 in changelog)
   migrating 519 KB in store; 1.05 MB tracked data
   migrating 3 filelogs containing 3 revisions (518 KB in store; 1.05 MB tracked data)
   finished migrating 3 filelog revisions across 3 filelogs; change in size: 0 bytes
   migrating 1 manifests containing 3 revisions (384 bytes in store; 238 bytes tracked data)
   finished migrating 3 manifest revisions across 1 manifests; change in size: -17 bytes
   migrating changelog containing 3 revisions (394 bytes in store; 199 bytes tracked data)
   finished migrating 3 changelog revisions; change in size: 0 bytes
   finished migrating 9 total revisions; total change in store size: -17 bytes
   copying phaseroots
   data fully upgraded in a temporary repository
   marking source repository as being upgraded; clients will be unable to read from repository
   starting in-place swap of repository data
   replaced files will be backed up at $TESTTMP/upgradegd/.hg/upgradebackup.* (glob)
   replacing store...
   store replacement complete; repository was inconsistent for *s (glob)
   finalizing requirements file and making repository readable again
   removing temporary repository $TESTTMP/upgradegd/.hg/upgrade.* (glob)
   copy of old repository backed up at $TESTTMP/upgradegd/.hg/upgradebackup.* (glob)
   the old repository will not be deleted; remove it to free up disk space once the upgraded repository is verified
 
 Original requirements backed up
 
   $ cat .hg/upgradebackup.*/requires
   dotencode
   fncache
   persistent-nodemap (rust !)
   revlogv1
   store
 
 generaldelta added to original requirements files
 
   $ cat .hg/requires
   dotencode
   fncache
   generaldelta
   persistent-nodemap (rust !)
   revlogv1
   store
 
 store directory has files we expect
 
   $ ls .hg/store
   00changelog.i
   00manifest.i
   data
   fncache
   phaseroots
   undo
   undo.backupfiles
   undo.phaseroots
 
 manifest should be generaldelta
 
   $ hg debugrevlog -m | grep flags
   flags  : inline, generaldelta
 
 verify should be happy
 
   $ hg verify
   checking changesets
   checking manifests
   crosschecking files in changesets and manifests
   checking files
   checked 3 changesets with 3 changes to 3 files
 
 old store should be backed up
 
   $ ls -d .hg/upgradebackup.*/
   .hg/upgradebackup.*/ (glob)
   $ ls .hg/upgradebackup.*/store
   00changelog.i
   00manifest.i
   data
   fncache
   phaseroots
   undo
   undo.backup.fncache
   undo.backupfiles
   undo.phaseroots
 
 unless --no-backup is passed
 
   $ rm -rf .hg/upgradebackup.*/
   $ hg debugupgraderepo --run --no-backup
   upgrade will perform the following actions:
   
   requirements
      preserved: dotencode, fncache, generaldelta, revlogv1, store (no-rust !)
      preserved: dotencode, fncache, generaldelta, persistent-nodemap, revlogv1, store (rust !)
      added: sparserevlog
   
   sparserevlog
      Revlog supports delta chain with more unused data between payload. These gaps will be skipped at read time. This allows for better delta chains, making a better compression and faster exchange with server.
   
   processed revlogs:
     - all-filelogs
     - changelog
     - manifest
   
   beginning upgrade...
   repository locked and read-only
   creating temporary repository to stage upgraded data: $TESTTMP/upgradegd/.hg/upgrade.* (glob)
   (it is safe to interrupt this process any time before data migration completes)
   migrating 9 total revisions (3 in filelogs, 3 in manifests, 3 in changelog)
   migrating 519 KB in store; 1.05 MB tracked data
   migrating 3 filelogs containing 3 revisions (518 KB in store; 1.05 MB tracked data)
   finished migrating 3 filelog revisions across 3 filelogs; change in size: 0 bytes
   migrating 1 manifests containing 3 revisions (367 bytes in store; 238 bytes tracked data)
   finished migrating 3 manifest revisions across 1 manifests; change in size: 0 bytes
   migrating changelog containing 3 revisions (394 bytes in store; 199 bytes tracked data)
   finished migrating 3 changelog revisions; change in size: 0 bytes
   finished migrating 9 total revisions; total change in store size: 0 bytes
   copying phaseroots
   data fully upgraded in a temporary repository
   marking source repository as being upgraded; clients will be unable to read from repository
   starting in-place swap of repository data
   replacing store...
   store replacement complete; repository was inconsistent for * (glob)
   finalizing requirements file and making repository readable again
   removing temporary repository $TESTTMP/upgradegd/.hg/upgrade.* (glob)
   $ ls -1 .hg/ | grep upgradebackup
   [1]
 
 We can restrict optimization to some revlog:
 
   $ hg debugupgrade --optimize re-delta-parent --run --manifest --no-backup --debug --traceback
   upgrade will perform the following actions:
   
   requirements
      preserved: dotencode, fncache, generaldelta, revlogv1, sparserevlog, store (no-rust !)
      preserved: dotencode, fncache, generaldelta, persistent-nodemap, revlogv1, sparserevlog, store (rust !)
   
   optimisations: re-delta-parent
   
   re-delta-parent
      deltas within internal storage will choose a new base revision if needed
   
   processed revlogs:
     - manifest
   
   beginning upgrade...
   repository locked and read-only
   creating temporary repository to stage upgraded data: $TESTTMP/upgradegd/.hg/upgrade.* (glob)
   (it is safe to interrupt this process any time before data migration completes)
   migrating 9 total revisions (3 in filelogs, 3 in manifests, 3 in changelog)
   migrating 519 KB in store; 1.05 MB tracked data
   migrating 3 filelogs containing 3 revisions (518 KB in store; 1.05 MB tracked data)
   blindly copying data/FooBarDirectory.d/f1.i containing 1 revisions
   blindly copying data/f0.i containing 1 revisions
   blindly copying data/f2.i containing 1 revisions
   finished migrating 3 filelog revisions across 3 filelogs; change in size: 0 bytes
   migrating 1 manifests containing 3 revisions (367 bytes in store; 238 bytes tracked data)
   cloning 3 revisions from 00manifest.i
   finished migrating 3 manifest revisions across 1 manifests; change in size: 0 bytes
   migrating changelog containing 3 revisions (394 bytes in store; 199 bytes tracked data)
   blindly copying 00changelog.i containing 3 revisions
   finished migrating 3 changelog revisions; change in size: 0 bytes
   finished migrating 9 total revisions; total change in store size: 0 bytes
   copying phaseroots
   data fully upgraded in a temporary repository
   marking source repository as being upgraded; clients will be unable to read from repository
   starting in-place swap of repository data
   replacing store...
   store replacement complete; repository was inconsistent for *s (glob)
   finalizing requirements file and making repository readable again
   removing temporary repository $TESTTMP/upgradegd/.hg/upgrade.* (glob)
 
 Check that the repo still works fine
 
   $ hg log -G --stat
   @  changeset:   2:76d4395f5413 (no-py3 !)
   @  changeset:   2:fca376863211 (py3 !)
   |  tag:         tip
   |  parent:      0:ba592bf28da2
   |  user:        test
   |  date:        Thu Jan 01 00:00:00 1970 +0000
   |  summary:     add f2
   |
   |   f2 |  100000 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
   |   1 files changed, 100000 insertions(+), 0 deletions(-)
   |
   | o  changeset:   1:2029ce2354e2
   |/   user:        test
   |    date:        Thu Jan 01 00:00:00 1970 +0000
   |    summary:     add f1
   |
   |
   o  changeset:   0:ba592bf28da2
      user:        test
      date:        Thu Jan 01 00:00:00 1970 +0000
      summary:     initial
   
   
 
   $ hg verify
   checking changesets
   checking manifests
   crosschecking files in changesets and manifests
   checking files
   checked 3 changesets with 3 changes to 3 files
 
 Check we can select negatively
 
   $ hg debugupgrade --optimize re-delta-parent --run --no-manifest --no-backup --debug --traceback
   upgrade will perform the following actions:
   
   requirements
      preserved: dotencode, fncache, generaldelta, revlogv1, sparserevlog, store (no-rust !)
      preserved: dotencode, fncache, generaldelta, persistent-nodemap, revlogv1, sparserevlog, store (rust !)
   
   optimisations: re-delta-parent
   
   re-delta-parent
      deltas within internal storage will choose a new base revision if needed
   
   processed revlogs:
     - all-filelogs
     - changelog
   
   beginning upgrade...
   repository locked and read-only
   creating temporary repository to stage upgraded data: $TESTTMP/upgradegd/.hg/upgrade.* (glob)
   (it is safe to interrupt this process any time before data migration completes)
   migrating 9 total revisions (3 in filelogs, 3 in manifests, 3 in changelog)
   migrating 519 KB in store; 1.05 MB tracked data
   migrating 3 filelogs containing 3 revisions (518 KB in store; 1.05 MB tracked data)
   cloning 1 revisions from data/FooBarDirectory.d/f1.i
   cloning 1 revisions from data/f0.i
   cloning 1 revisions from data/f2.i
   finished migrating 3 filelog revisions across 3 filelogs; change in size: 0 bytes
   migrating 1 manifests containing 3 revisions (367 bytes in store; 238 bytes tracked data)
   blindly copying 00manifest.i containing 3 revisions
   finished migrating 3 manifest revisions across 1 manifests; change in size: 0 bytes
   migrating changelog containing 3 revisions (394 bytes in store; 199 bytes tracked data)
   cloning 3 revisions from 00changelog.i
   finished migrating 3 changelog revisions; change in size: 0 bytes
   finished migrating 9 total revisions; total change in store size: 0 bytes
   copying phaseroots
   data fully upgraded in a temporary repository
   marking source repository as being upgraded; clients will be unable to read from repository
   starting in-place swap of repository data
   replacing store...
   store replacement complete; repository was inconsistent for *s (glob)
   finalizing requirements file and making repository readable again
   removing temporary repository $TESTTMP/upgradegd/.hg/upgrade.* (glob)
   $ hg verify
   checking changesets
   checking manifests
   crosschecking files in changesets and manifests
   checking files
   checked 3 changesets with 3 changes to 3 files
 
 Check that we can select changelog only
 
   $ hg debugupgrade --optimize re-delta-parent --run --changelog --no-backup --debug --traceback
   upgrade will perform the following actions:
   
   requirements
      preserved: dotencode, fncache, generaldelta, revlogv1, sparserevlog, store (no-rust !)
      preserved: dotencode, fncache, generaldelta, persistent-nodemap, revlogv1, sparserevlog, store (rust !)
   
   optimisations: re-delta-parent
   
   re-delta-parent
      deltas within internal storage will choose a new base revision if needed
   
   processed revlogs:
     - changelog
   
   beginning upgrade...
   repository locked and read-only
   creating temporary repository to stage upgraded data: $TESTTMP/upgradegd/.hg/upgrade.* (glob)
   (it is safe to interrupt this process any time before data migration completes)
   migrating 9 total revisions (3 in filelogs, 3 in manifests, 3 in changelog)
   migrating 519 KB in store; 1.05 MB tracked data
   migrating 3 filelogs containing 3 revisions (518 KB in store; 1.05 MB tracked data)
   blindly copying data/FooBarDirectory.d/f1.i containing 1 revisions
   blindly copying data/f0.i containing 1 revisions
   blindly copying data/f2.i containing 1 revisions
   finished migrating 3 filelog revisions across 3 filelogs; change in size: 0 bytes
   migrating 1 manifests containing 3 revisions (367 bytes in store; 238 bytes tracked data)
   blindly copying 00manifest.i containing 3 revisions
   finished migrating 3 manifest revisions across 1 manifests; change in size: 0 bytes
   migrating changelog containing 3 revisions (394 bytes in store; 199 bytes tracked data)
   cloning 3 revisions from 00changelog.i
   finished migrating 3 changelog revisions; change in size: 0 bytes
   finished migrating 9 total revisions; total change in store size: 0 bytes
   copying phaseroots
   data fully upgraded in a temporary repository
   marking source repository as being upgraded; clients will be unable to read from repository
   starting in-place swap of repository data
   replacing store...
   store replacement complete; repository was inconsistent for *s (glob)
   finalizing requirements file and making repository readable again
   removing temporary repository $TESTTMP/upgradegd/.hg/upgrade.* (glob)
   $ hg verify
   checking changesets
   checking manifests
   crosschecking files in changesets and manifests
   checking files
   checked 3 changesets with 3 changes to 3 files
 
 Check that we can select filelog only
 
   $ hg debugupgrade --optimize re-delta-parent --run --no-changelog --no-manifest --no-backup --debug --traceback
   upgrade will perform the following actions:
   
   requirements
      preserved: dotencode, fncache, generaldelta, revlogv1, sparserevlog, store (no-rust !)
      preserved: dotencode, fncache, generaldelta, persistent-nodemap, revlogv1, sparserevlog, store (rust !)
   
   optimisations: re-delta-parent
   
   re-delta-parent
      deltas within internal storage will choose a new base revision if needed
   
   processed revlogs:
     - all-filelogs
   
   beginning upgrade...
   repository locked and read-only
   creating temporary repository to stage upgraded data: $TESTTMP/upgradegd/.hg/upgrade.* (glob)
   (it is safe to interrupt this process any time before data migration completes)
   migrating 9 total revisions (3 in filelogs, 3 in manifests, 3 in changelog)
   migrating 519 KB in store; 1.05 MB tracked data
   migrating 3 filelogs containing 3 revisions (518 KB in store; 1.05 MB tracked data)
   cloning 1 revisions from data/FooBarDirectory.d/f1.i
   cloning 1 revisions from data/f0.i
   cloning 1 revisions from data/f2.i
   finished migrating 3 filelog revisions across 3 filelogs; change in size: 0 bytes
   migrating 1 manifests containing 3 revisions (367 bytes in store; 238 bytes tracked data)
   blindly copying 00manifest.i containing 3 revisions
   finished migrating 3 manifest revisions across 1 manifests; change in size: 0 bytes
   migrating changelog containing 3 revisions (394 bytes in store; 199 bytes tracked data)
   blindly copying 00changelog.i containing 3 revisions
   finished migrating 3 changelog revisions; change in size: 0 bytes
   finished migrating 9 total revisions; total change in store size: 0 bytes
   copying phaseroots
   data fully upgraded in a temporary repository
   marking source repository as being upgraded; clients will be unable to read from repository
   starting in-place swap of repository data
   replacing store...
   store replacement complete; repository was inconsistent for *s (glob)
   finalizing requirements file and making repository readable again
   removing temporary repository $TESTTMP/upgradegd/.hg/upgrade.* (glob)
   $ hg verify
   checking changesets
   checking manifests
   crosschecking files in changesets and manifests
   checking files
   checked 3 changesets with 3 changes to 3 files
 
 
 Check you can't skip revlog clone during important format downgrade
 
   $ echo "[format]" > .hg/hgrc
   $ echo "sparse-revlog=no" >> .hg/hgrc
   $ hg debugupgrade --optimize re-delta-parent --run --manifest --no-backup --debug --traceback
   ignoring revlogs selection flags, format requirements change: sparserevlog
   upgrade will perform the following actions:
   
   requirements
      preserved: dotencode, fncache, generaldelta, revlogv1, store (no-rust !)
      preserved: dotencode, fncache, generaldelta, persistent-nodemap, revlogv1, store (rust !)
      removed: sparserevlog
   
   optimisations: re-delta-parent
   
   re-delta-parent
      deltas within internal storage will choose a new base revision if needed
   
   processed revlogs:
     - all-filelogs
     - changelog
     - manifest
   
   beginning upgrade...
   repository locked and read-only
   creating temporary repository to stage upgraded data: $TESTTMP/upgradegd/.hg/upgrade.* (glob)
   (it is safe to interrupt this process any time before data migration completes)
   migrating 9 total revisions (3 in filelogs, 3 in manifests, 3 in changelog)
   migrating 519 KB in store; 1.05 MB tracked data
   migrating 3 filelogs containing 3 revisions (518 KB in store; 1.05 MB tracked data)
   cloning 1 revisions from data/FooBarDirectory.d/f1.i
   cloning 1 revisions from data/f0.i
   cloning 1 revisions from data/f2.i
   finished migrating 3 filelog revisions across 3 filelogs; change in size: 0 bytes
   migrating 1 manifests containing 3 revisions (367 bytes in store; 238 bytes tracked data)
   cloning 3 revisions from 00manifest.i
   finished migrating 3 manifest revisions across 1 manifests; change in size: 0 bytes
   migrating changelog containing 3 revisions (394 bytes in store; 199 bytes tracked data)
   cloning 3 revisions from 00changelog.i
   finished migrating 3 changelog revisions; change in size: 0 bytes
   finished migrating 9 total revisions; total change in store size: 0 bytes
   copying phaseroots
   data fully upgraded in a temporary repository
   marking source repository as being upgraded; clients will be unable to read from repository
   starting in-place swap of repository data
   replacing store...
   store replacement complete; repository was inconsistent for *s (glob)
   finalizing requirements file and making repository readable again
   removing temporary repository $TESTTMP/upgradegd/.hg/upgrade.* (glob)
   $ hg verify
   checking changesets
   checking manifests
   crosschecking files in changesets and manifests
   checking files
   checked 3 changesets with 3 changes to 3 files
 
 Check you can't skip revlog clone during important format upgrade
 
   $ echo "sparse-revlog=yes" >> .hg/hgrc
   $ hg debugupgrade --optimize re-delta-parent --run --manifest --no-backup --debug --traceback
   ignoring revlogs selection flags, format requirements change: sparserevlog
   upgrade will perform the following actions:
   
   requirements
      preserved: dotencode, fncache, generaldelta, revlogv1, store (no-rust !)
      preserved: dotencode, fncache, generaldelta, persistent-nodemap, revlogv1, store (rust !)
      added: sparserevlog
   
   optimisations: re-delta-parent
   
   sparserevlog
      Revlog supports delta chain with more unused data between payload. These gaps will be skipped at read time. This allows for better delta chains, making a better compression and faster exchange with server.
   
   re-delta-parent
      deltas within internal storage will choose a new base revision if needed
   
   processed revlogs:
     - all-filelogs
     - changelog
     - manifest
   
   beginning upgrade...
   repository locked and read-only
   creating temporary repository to stage upgraded data: $TESTTMP/upgradegd/.hg/upgrade.* (glob)
   (it is safe to interrupt this process any time before data migration completes)
   migrating 9 total revisions (3 in filelogs, 3 in manifests, 3 in changelog)
   migrating 519 KB in store; 1.05 MB tracked data
   migrating 3 filelogs containing 3 revisions (518 KB in store; 1.05 MB tracked data)
   cloning 1 revisions from data/FooBarDirectory.d/f1.i
   cloning 1 revisions from data/f0.i
   cloning 1 revisions from data/f2.i
   finished migrating 3 filelog revisions across 3 filelogs; change in size: 0 bytes
   migrating 1 manifests containing 3 revisions (367 bytes in store; 238 bytes tracked data)
   cloning 3 revisions from 00manifest.i
   finished migrating 3 manifest revisions across 1 manifests; change in size: 0 bytes
   migrating changelog containing 3 revisions (394 bytes in store; 199 bytes tracked data)
   cloning 3 revisions from 00changelog.i
   finished migrating 3 changelog revisions; change in size: 0 bytes
   finished migrating 9 total revisions; total change in store size: 0 bytes
   copying phaseroots
   data fully upgraded in a temporary repository
   marking source repository as being upgraded; clients will be unable to read from repository
   starting in-place swap of repository data
   replacing store...
   store replacement complete; repository was inconsistent for *s (glob)
   finalizing requirements file and making repository readable again
   removing temporary repository $TESTTMP/upgradegd/.hg/upgrade.* (glob)
   $ hg verify
   checking changesets
   checking manifests
   crosschecking files in changesets and manifests
   checking files
   checked 3 changesets with 3 changes to 3 files
 
   $ cd ..
 
 store files with special filenames aren't encoded during copy
 
   $ hg init store-filenames
   $ cd store-filenames
   $ touch foo
   $ hg -q commit -A -m initial
   $ touch .hg/store/.XX_special_filename
 
   $ hg debugupgraderepo --run
   nothing to do
   $ hg debugupgraderepo --run --optimize 're-delta-fulladd'
   upgrade will perform the following actions:
   
   requirements
      preserved: dotencode, fncache, generaldelta, revlogv1, sparserevlog, store (no-rust !)
      preserved: dotencode, fncache, generaldelta, persistent-nodemap, revlogv1, sparserevlog, store (rust !)
   
   optimisations: re-delta-fulladd
   
   re-delta-fulladd
      each revision will be added as new content to the internal storage; this will likely drastically slow down execution time, but some extensions might need it
   
   processed revlogs:
     - all-filelogs
     - changelog
     - manifest
   
   beginning upgrade...
   repository locked and read-only
   creating temporary repository to stage upgraded data: $TESTTMP/store-filenames/.hg/upgrade.* (glob)
   (it is safe to interrupt this process any time before data migration completes)
   migrating 3 total revisions (1 in filelogs, 1 in manifests, 1 in changelog)
   migrating 301 bytes in store; 107 bytes tracked data
   migrating 1 filelogs containing 1 revisions (64 bytes in store; 0 bytes tracked data)
   finished migrating 1 filelog revisions across 1 filelogs; change in size: 0 bytes
   migrating 1 manifests containing 1 revisions (110 bytes in store; 45 bytes tracked data)
   finished migrating 1 manifest revisions across 1 manifests; change in size: 0 bytes
   migrating changelog containing 1 revisions (127 bytes in store; 62 bytes tracked data)
   finished migrating 1 changelog revisions; change in size: 0 bytes
   finished migrating 3 total revisions; total change in store size: 0 bytes
   copying .XX_special_filename
   copying phaseroots
   data fully upgraded in a temporary repository
   marking source repository as being upgraded; clients will be unable to read from repository
   starting in-place swap of repository data
   replaced files will be backed up at $TESTTMP/store-filenames/.hg/upgradebackup.* (glob)
   replacing store...
   store replacement complete; repository was inconsistent for *s (glob)
   finalizing requirements file and making repository readable again
   removing temporary repository $TESTTMP/store-filenames/.hg/upgrade.* (glob)
   copy of old repository backed up at $TESTTMP/store-filenames/.hg/upgradebackup.* (glob)
   the old repository will not be deleted; remove it to free up disk space once the upgraded repository is verified
 
 fncache is valid after upgrade
 
   $ hg debugrebuildfncache
   fncache already up to date
 
   $ cd ..
 
 Check upgrading a large file repository
 ---------------------------------------
 
   $ hg init largefilesrepo
   $ cat << EOF >> largefilesrepo/.hg/hgrc
   > [extensions]
   > largefiles =
   > EOF
 
   $ cd largefilesrepo
   $ touch foo
   $ hg add --large foo
   $ hg -q commit -m initial
   $ cat .hg/requires
   dotencode
   fncache
   generaldelta
   largefiles
   persistent-nodemap (rust !)
   revlogv1
   sparserevlog
   store
 
   $ hg debugupgraderepo --run
   nothing to do
   $ cat .hg/requires
   dotencode
   fncache
   generaldelta
   largefiles
   persistent-nodemap (rust !)
   revlogv1
   sparserevlog
   store
 
   $ cat << EOF >> .hg/hgrc
   > [extensions]
   > lfs =
   > [lfs]
   > threshold = 10
   > EOF
   $ echo '123456789012345' > lfs.bin
   $ hg ci -Am 'lfs.bin'
   adding lfs.bin
   $ grep lfs .hg/requires
   lfs
   $ find .hg/store/lfs -type f
   .hg/store/lfs/objects/d0/beab232adff5ba365880366ad30b1edb85c4c5372442b5d2fe27adc96d653f
 
   $ hg debugupgraderepo --run
   nothing to do
 
   $ grep lfs .hg/requires
   lfs
   $ find .hg/store/lfs -type f
   .hg/store/lfs/objects/d0/beab232adff5ba365880366ad30b1edb85c4c5372442b5d2fe27adc96d653f
   $ hg verify
   checking changesets
   checking manifests
   crosschecking files in changesets and manifests
   checking files
   checked 2 changesets with 2 changes to 2 files
   $ hg debugdata lfs.bin 0
   version https://git-lfs.github.com/spec/v1
   oid sha256:d0beab232adff5ba365880366ad30b1edb85c4c5372442b5d2fe27adc96d653f
   size 16
   x-is-binary 0
 
   $ cd ..
 
 repository config is taken in account
 -------------------------------------
 
   $ cat << EOF >> $HGRCPATH
   > [format]
   > maxchainlen = 1
   > EOF
 
   $ hg init localconfig
   $ cd localconfig
   $ cat << EOF > file
   > some content
   > with some length
   > to make sure we get a delta
   > after changes
   > very long
   > very long
   > very long
   > very long
   > very long
   > very long
   > very long
   > very long
   > very long
   > very long
   > very long
   > EOF
   $ hg -q commit -A -m A
   $ echo "new line" >> file
   $ hg -q commit -m B
   $ echo "new line" >> file
   $ hg -q commit -m C
 
   $ cat << EOF >> .hg/hgrc
   > [format]
   > maxchainlen = 9001
   > EOF
   $ hg config format
   format.revlog-compression=$BUNDLE2_COMPRESSIONS$
   format.maxchainlen=9001
   $ hg debugdeltachain file
       rev  chain# chainlen     prev   delta       size    rawsize  chainsize     ratio   lindist extradist extraratio   readsize largestblk rddensity srchunks
         0       1        1       -1    base         77        182         77   0.42308        77         0    0.00000         77         77   1.00000        1
         1       1        2        0      p1         21        191         98   0.51309        98         0    0.00000         98         98   1.00000        1
         2       1        2        0   other         30        200        107   0.53500       128        21    0.19626        128        128   0.83594        1
 
   $ hg debugupgraderepo --run --optimize 're-delta-all'
   upgrade will perform the following actions:
   
   requirements
      preserved: dotencode, fncache, generaldelta, revlogv1, sparserevlog, store (no-rust !)
      preserved: dotencode, fncache, generaldelta, persistent-nodemap, revlogv1, sparserevlog, store (rust !)
   
   optimisations: re-delta-all
   
   re-delta-all
      deltas within internal storage will be fully recomputed; this will likely drastically slow down execution time
   
   processed revlogs:
     - all-filelogs
     - changelog
     - manifest
   
   beginning upgrade...
   repository locked and read-only
   creating temporary repository to stage upgraded data: $TESTTMP/localconfig/.hg/upgrade.* (glob)
   (it is safe to interrupt this process any time before data migration completes)
   migrating 9 total revisions (3 in filelogs, 3 in manifests, 3 in changelog)
   migrating 1019 bytes in store; 882 bytes tracked data
   migrating 1 filelogs containing 3 revisions (320 bytes in store; 573 bytes tracked data)
   finished migrating 3 filelog revisions across 1 filelogs; change in size: -9 bytes
   migrating 1 manifests containing 3 revisions (333 bytes in store; 138 bytes tracked data)
   finished migrating 3 manifest revisions across 1 manifests; change in size: 0 bytes
   migrating changelog containing 3 revisions (366 bytes in store; 171 bytes tracked data)
   finished migrating 3 changelog revisions; change in size: 0 bytes
   finished migrating 9 total revisions; total change in store size: -9 bytes
   copying phaseroots
   data fully upgraded in a temporary repository
   marking source repository as being upgraded; clients will be unable to read from repository
   starting in-place swap of repository data
   replaced files will be backed up at $TESTTMP/localconfig/.hg/upgradebackup.* (glob)
   replacing store...
   store replacement complete; repository was inconsistent for *s (glob)
   finalizing requirements file and making repository readable again
   removing temporary repository $TESTTMP/localconfig/.hg/upgrade.* (glob)
   copy of old repository backed up at $TESTTMP/localconfig/.hg/upgradebackup.* (glob)
   the old repository will not be deleted; remove it to free up disk space once the upgraded repository is verified
   $ hg debugdeltachain file
       rev  chain# chainlen     prev   delta       size    rawsize  chainsize     ratio   lindist extradist extraratio   readsize largestblk rddensity srchunks
         0       1        1       -1    base         77        182         77   0.42308        77         0    0.00000         77         77   1.00000        1
         1       1        2        0      p1         21        191         98   0.51309        98         0    0.00000         98         98   1.00000        1
         2       1        3        1      p1         21        200        119   0.59500       119         0    0.00000        119        119   1.00000        1
   $ cd ..
 
   $ cat << EOF >> $HGRCPATH
   > [format]
   > maxchainlen = 9001
   > EOF
 
 Check upgrading a sparse-revlog repository
 ---------------------------------------
 
   $ hg init sparserevlogrepo --config format.sparse-revlog=no
   $ cd sparserevlogrepo
   $ touch foo
   $ hg add foo
   $ hg -q commit -m "foo"
   $ cat .hg/requires
   dotencode
   fncache
   generaldelta
   persistent-nodemap (rust !)
   revlogv1
   store
 
 Check that we can add the sparse-revlog format requirement
   $ hg --config format.sparse-revlog=yes debugupgraderepo --run --quiet
   upgrade will perform the following actions:
   
   requirements
      preserved: dotencode, fncache, generaldelta, revlogv1, store (no-rust !)
      preserved: dotencode, fncache, generaldelta, persistent-nodemap, revlogv1, store (rust !)
      added: sparserevlog
   
   processed revlogs:
     - all-filelogs
     - changelog
     - manifest
   
   $ cat .hg/requires
   dotencode
   fncache
   generaldelta
   persistent-nodemap (rust !)
   revlogv1
   sparserevlog
   store
 
 Check that we can remove the sparse-revlog format requirement
   $ hg --config format.sparse-revlog=no debugupgraderepo --run --quiet
   upgrade will perform the following actions:
   
   requirements
      preserved: dotencode, fncache, generaldelta, revlogv1, store (no-rust !)
      preserved: dotencode, fncache, generaldelta, persistent-nodemap, revlogv1, store (rust !)
      removed: sparserevlog
   
   processed revlogs:
     - all-filelogs
     - changelog
     - manifest
   
   $ cat .hg/requires
   dotencode
   fncache
   generaldelta
   persistent-nodemap (rust !)
   revlogv1
   store
 
 #if zstd
 
 Check upgrading to a zstd revlog
 --------------------------------
 
 upgrade
 
   $ hg --config format.revlog-compression=zstd debugupgraderepo --run  --no-backup --quiet
   upgrade will perform the following actions:
   
   requirements
      preserved: dotencode, fncache, generaldelta, revlogv1, store (no-rust !)
      preserved: dotencode, fncache, generaldelta, persistent-nodemap, revlogv1, store (rust !)
      added: revlog-compression-zstd, sparserevlog
   
   processed revlogs:
     - all-filelogs
     - changelog
     - manifest
   
   $ hg debugformat -v
   format-variant     repo config default
   fncache:            yes    yes     yes
   dirstate-v2:         no     no      no
   dotencode:          yes    yes     yes
   generaldelta:       yes    yes     yes
   share-safe:          no     no      no
   sparserevlog:       yes    yes     yes
   persistent-nodemap:  no     no      no (no-rust !)
   persistent-nodemap: yes    yes      no (rust !)
   copies-sdc:          no     no      no
   revlog-v2:           no     no      no
   changelog-v2:        no     no      no
   plain-cl-delta:     yes    yes     yes
   compression:        zlib   zlib    zlib (no-zstd !)
   compression:        zstd   zlib    zstd (zstd !)
   compression-level:  default default default
   $ cat .hg/requires
   dotencode
   fncache
   generaldelta
   persistent-nodemap (rust !)
   revlog-compression-zstd
   revlogv1
   sparserevlog
   store
 
 downgrade
 
   $ hg debugupgraderepo --run --no-backup --quiet
   upgrade will perform the following actions:
   
   requirements
      preserved: dotencode, fncache, generaldelta, revlogv1, sparserevlog, store (no-rust !)
      preserved: dotencode, fncache, generaldelta, persistent-nodemap, revlogv1, sparserevlog, store (rust !)
      removed: revlog-compression-zstd
   
   processed revlogs:
     - all-filelogs
     - changelog
     - manifest
   
   $ hg debugformat -v
   format-variant     repo config default
   fncache:            yes    yes     yes
   dirstate-v2:         no     no      no
   dotencode:          yes    yes     yes
   generaldelta:       yes    yes     yes
   share-safe:          no     no      no
   sparserevlog:       yes    yes     yes
   persistent-nodemap:  no     no      no (no-rust !)
   persistent-nodemap: yes    yes      no (rust !)
   copies-sdc:          no     no      no
   revlog-v2:           no     no      no
   changelog-v2:        no     no      no
   plain-cl-delta:     yes    yes     yes
   compression:        zlib   zlib    zlib (no-zstd !)
   compression:        zlib   zlib    zstd (zstd !)
   compression-level:  default default default
   $ cat .hg/requires
   dotencode
   fncache
   generaldelta
   persistent-nodemap (rust !)
   revlogv1
   sparserevlog
   store
 
 upgrade from hgrc
 
   $ cat >> .hg/hgrc << EOF
   > [format]
   > revlog-compression=zstd
   > EOF
   $ hg debugupgraderepo --run --no-backup --quiet
   upgrade will perform the following actions:
   
   requirements
      preserved: dotencode, fncache, generaldelta, revlogv1, sparserevlog, store (no-rust !)
      preserved: dotencode, fncache, generaldelta, persistent-nodemap, revlogv1, sparserevlog, store (rust !)
      added: revlog-compression-zstd
   
   processed revlogs:
     - all-filelogs
     - changelog
     - manifest
   
   $ hg debugformat -v
   format-variant     repo config default
   fncache:            yes    yes     yes
   dirstate-v2:         no     no      no
   dotencode:          yes    yes     yes
   generaldelta:       yes    yes     yes
   share-safe:          no     no      no
   sparserevlog:       yes    yes     yes
   persistent-nodemap:  no     no      no (no-rust !)
   persistent-nodemap: yes    yes      no (rust !)
   copies-sdc:          no     no      no
   revlog-v2:           no     no      no
   changelog-v2:        no     no      no
   plain-cl-delta:     yes    yes     yes
   compression:        zlib   zlib    zlib (no-zstd !)
   compression:        zstd   zstd    zstd (zstd !)
   compression-level:  default default default
   $ cat .hg/requires
   dotencode
   fncache
   generaldelta
   persistent-nodemap (rust !)
   revlog-compression-zstd
   revlogv1
   sparserevlog
   store
 
 #endif
 
 Check upgrading to a revlog format supporting sidedata
 ------------------------------------------------------
 
 upgrade
 
   $ hg debugsidedata -c 0
   $ hg --config experimental.revlogv2=enable-unstable-format-and-corrupt-my-data debugupgraderepo --run  --no-backup --config "extensions.sidedata=$TESTDIR/testlib/ext-sidedata.py" --quiet
   upgrade will perform the following actions:
   
   requirements
      preserved: dotencode, fncache, generaldelta, store (no-zstd !)
      preserved: dotencode, fncache, generaldelta, revlog-compression-zstd, sparserevlog, store (zstd no-rust !)
      preserved: dotencode, fncache, generaldelta, persistent-nodemap, revlog-compression-zstd, sparserevlog, store (rust !)
      removed: revlogv1
      added: exp-revlogv2.2 (zstd !)
      added: exp-revlogv2.2, sparserevlog (no-zstd !)
   
   processed revlogs:
     - all-filelogs
     - changelog
     - manifest
   
   $ hg debugformat -v
   format-variant     repo config default
   fncache:            yes    yes     yes
   dirstate-v2:         no     no      no
   dotencode:          yes    yes     yes
   generaldelta:       yes    yes     yes
   share-safe:          no     no      no
   sparserevlog:       yes    yes     yes
   persistent-nodemap:  no     no      no (no-rust !)
   persistent-nodemap: yes    yes      no (rust !)
   copies-sdc:          no     no      no
   revlog-v2:          yes     no      no
   changelog-v2:        no     no      no
   plain-cl-delta:     yes    yes     yes
   compression:        zlib   zlib    zlib (no-zstd !)
   compression:        zstd   zstd    zstd (zstd !)
   compression-level:  default default default
   $ cat .hg/requires
   dotencode
   exp-revlogv2.2
   fncache
   generaldelta
   persistent-nodemap (rust !)
   revlog-compression-zstd (zstd !)
   sparserevlog
   store
   $ hg debugsidedata -c 0
   2 sidedata entries
    entry-0001 size 4
    entry-0002 size 32
 
 downgrade
 
   $ hg debugupgraderepo --config experimental.revlogv2=no --run --no-backup --quiet
   upgrade will perform the following actions:
   
   requirements
      preserved: dotencode, fncache, generaldelta, sparserevlog, store (no-zstd !)
      preserved: dotencode, fncache, generaldelta, revlog-compression-zstd, sparserevlog, store (zstd no-rust !)
      preserved: dotencode, fncache, generaldelta, persistent-nodemap, revlog-compression-zstd, sparserevlog, store (rust !)
      removed: exp-revlogv2.2
      added: revlogv1
   
   processed revlogs:
     - all-filelogs
     - changelog
     - manifest
   
   $ hg debugformat -v
   format-variant     repo config default
   fncache:            yes    yes     yes
   dirstate-v2:         no     no      no
   dotencode:          yes    yes     yes
   generaldelta:       yes    yes     yes
   share-safe:          no     no      no
   sparserevlog:       yes    yes     yes
   persistent-nodemap:  no     no      no (no-rust !)
   persistent-nodemap: yes    yes      no (rust !)
   copies-sdc:          no     no      no
   revlog-v2:           no     no      no
   changelog-v2:        no     no      no
   plain-cl-delta:     yes    yes     yes
   compression:        zlib   zlib    zlib (no-zstd !)
   compression:        zstd   zstd    zstd (zstd !)
   compression-level:  default default default
   $ cat .hg/requires
   dotencode
   fncache
   generaldelta
   persistent-nodemap (rust !)
   revlog-compression-zstd (zstd !)
   revlogv1
   sparserevlog
   store
   $ hg debugsidedata -c 0
 
 upgrade from hgrc
 
   $ cat >> .hg/hgrc << EOF
   > [experimental]
   > revlogv2=enable-unstable-format-and-corrupt-my-data
   > EOF
   $ hg debugupgraderepo --run --no-backup --quiet
   upgrade will perform the following actions:
   
   requirements
      preserved: dotencode, fncache, generaldelta, sparserevlog, store (no-zstd !)
      preserved: dotencode, fncache, generaldelta, revlog-compression-zstd, sparserevlog, store (zstd no-rust !)
      preserved: dotencode, fncache, generaldelta, persistent-nodemap, revlog-compression-zstd, sparserevlog, store (rust !)
      removed: revlogv1
      added: exp-revlogv2.2
   
   processed revlogs:
     - all-filelogs
     - changelog
     - manifest
   
   $ hg debugformat -v
   format-variant     repo config default
   fncache:            yes    yes     yes
   dirstate-v2:         no     no      no
   dotencode:          yes    yes     yes
   generaldelta:       yes    yes     yes
   share-safe:          no     no      no
   sparserevlog:       yes    yes     yes
   persistent-nodemap:  no     no      no (no-rust !)
   persistent-nodemap: yes    yes      no (rust !)
   copies-sdc:          no     no      no
   revlog-v2:          yes    yes      no
   changelog-v2:        no     no      no
   plain-cl-delta:     yes    yes     yes
   compression:        zlib   zlib    zlib (no-zstd !)
   compression:        zstd   zstd    zstd (zstd !)
   compression-level:  default default default
   $ cat .hg/requires
   dotencode
   exp-revlogv2.2
   fncache
   generaldelta
   persistent-nodemap (rust !)
   revlog-compression-zstd (zstd !)
   sparserevlog
   store
   $ hg debugsidedata -c 0
 
 Demonstrate that nothing to perform upgrade will still run all the way through
 
   $ hg debugupgraderepo --run
   nothing to do
 
 #if no-rust
 
   $ cat << EOF >> $HGRCPATH
   > [storage]
   > dirstate-v2.slow-path = allow
   > EOF
 
 #endif
 
 Upgrade to dirstate-v2
 
   $ hg debugformat -v --config format.exp-rc-dirstate-v2=1 | grep dirstate-v2
   dirstate-v2:         no    yes      no
   $ hg debugupgraderepo --config format.exp-rc-dirstate-v2=1 --run
   upgrade will perform the following actions:
   
   requirements
      preserved: * (glob)
      added: dirstate-v2
   
   dirstate-v2
      "hg status" will be faster
   
   processed revlogs:
     - all-filelogs
     - changelog
     - manifest
   
   beginning upgrade...
   repository locked and read-only
   creating temporary repository to stage upgraded data: $TESTTMP/sparserevlogrepo/.hg/upgrade.* (glob)
   (it is safe to interrupt this process any time before data migration completes)
   upgrading to dirstate-v2 from v1
   replaced files will be backed up at $TESTTMP/sparserevlogrepo/.hg/upgradebackup.* (glob)
   removing temporary repository $TESTTMP/sparserevlogrepo/.hg/upgrade.* (glob)
   $ ls .hg/upgradebackup.*/dirstate
   .hg/upgradebackup.*/dirstate (glob)
   $ hg debugformat -v | grep dirstate-v2
   dirstate-v2:        yes     no      no
   $ hg status
   $ dd bs=12 count=1 if=.hg/dirstate 2> /dev/null
   dirstate-v2
 
 Downgrade from dirstate-v2
 
   $ hg debugupgraderepo --run
   upgrade will perform the following actions:
   
   requirements
      preserved: * (glob)
      removed: dirstate-v2
   
   processed revlogs:
     - all-filelogs
     - changelog
     - manifest
   
   beginning upgrade...
   repository locked and read-only
   creating temporary repository to stage upgraded data: $TESTTMP/sparserevlogrepo/.hg/upgrade.* (glob)
   (it is safe to interrupt this process any time before data migration completes)
   downgrading from dirstate-v2 to v1
   replaced files will be backed up at $TESTTMP/sparserevlogrepo/.hg/upgradebackup.* (glob)
   removing temporary repository $TESTTMP/sparserevlogrepo/.hg/upgrade.* (glob)
   $ hg debugformat -v | grep dirstate-v2
   dirstate-v2:         no     no      no
   $ hg status
+
+  $ cd ..
+
+dirstate-v2: upgrade and downgrade from and empty repository:
+-------------------------------------------------------------
+
+  $ hg init --config format.exp-rc-dirstate-v2=no dirstate-v2-empty
+  $ cd dirstate-v2-empty
+  $ hg debugformat | grep dirstate-v2
+  dirstate-v2:         no
+
+upgrade
+
+  $ hg debugupgraderepo --run --config format.exp-rc-dirstate-v2=yes
+  upgrade will perform the following actions:
+  
+  requirements
+     preserved: * (glob)
+     added: dirstate-v2
+  
+  dirstate-v2
+     "hg status" will be faster
+  
+  processed revlogs:
+    - all-filelogs
+    - changelog
+    - manifest
+  
+  beginning upgrade...
+  repository locked and read-only
+  creating temporary repository to stage upgraded data: $TESTTMP/dirstate-v2-empty/.hg/upgrade.* (glob)
+  (it is safe to interrupt this process any time before data migration completes)
+  upgrading to dirstate-v2 from v1
+  replaced files will be backed up at $TESTTMP/dirstate-v2-empty/.hg/upgradebackup.* (glob)
+  removing temporary repository $TESTTMP/dirstate-v2-empty/.hg/upgrade.* (glob)
+  $ hg debugformat | grep dirstate-v2
+  dirstate-v2:        yes
+
+downgrade
+
+  $ hg debugupgraderepo --run --config format.exp-rc-dirstate-v2=no
+  upgrade will perform the following actions:
+  
+  requirements
+     preserved: * (glob)
+     removed: dirstate-v2
+  
+  processed revlogs:
+    - all-filelogs
+    - changelog
+    - manifest
+  
+  beginning upgrade...
+  repository locked and read-only
+  creating temporary repository to stage upgraded data: $TESTTMP/dirstate-v2-empty/.hg/upgrade.* (glob)
+  (it is safe to interrupt this process any time before data migration completes)
+  downgrading from dirstate-v2 to v1
+  replaced files will be backed up at $TESTTMP/dirstate-v2-empty/.hg/upgradebackup.* (glob)
+  removing temporary repository $TESTTMP/dirstate-v2-empty/.hg/upgrade.* (glob)
+  $ hg debugformat | grep dirstate-v2
+  dirstate-v2:         no
+
+  $ cd ..