phase: introduce a dedicated requirement for the `archived` phase

See inline documentation for details.

mercurial/configitems.py

@@ -1431,6 +1431,23 b' coreconfigitem('
     default=False,
     experimental=True,
 )
+# The interaction between the archived phase and obsolescence markers needs to
+# be sorted out before wider usage of this are to be considered.
+#
+# At the time this message is written, behavior when archiving obsolete
+# changeset differ significantly from stripping. As part of stripping, we also
+# remove the obsolescence marker associated to the stripped changesets,
+# revealing the precedecessors changesets when applicable. When archiving, we
+# don't touch the obsolescence markers, keeping everything hidden. This can
+# result in quite confusing situation for people combining exchanging draft
+# with the archived phases. As some markers needed by others may be skipped
+# during exchange.
+coreconfigitem(
+    b'format',
+    b'exp-archived-phase',
+    default=False,
+    experimental=True,
+)
 coreconfigitem(
     b'shelve',
     b'store',

mercurial/localrepo.py

@@ -1281,6 +1281,7 b' class localrepository:'
     """
 
     _basesupported = {
+        requirementsmod.ARCHIVED_PHASE_REQUIREMENT,
         requirementsmod.BOOKMARKS_IN_STORE_REQUIREMENT,
         requirementsmod.CHANGELOGV2_REQUIREMENT,
         requirementsmod.COPIESSDC_REQUIREMENT,
@@ -3664,6 +3665,10 b' def newreporequirements(ui, createopts):'
     if ui.configbool(b'format', b'internal-phase'):
         requirements.add(requirementsmod.INTERNAL_PHASE_REQUIREMENT)
 
+    # experimental config: format.exp-archived-phase
+    if ui.configbool(b'format', b'exp-archived-phase'):
+        requirements.add(requirementsmod.ARCHIVED_PHASE_REQUIREMENT)
+
     if createopts.get(b'narrowfiles'):
         requirements.add(requirementsmod.NARROW_REQUIREMENT)
 

mercurial/phases.py

@@ -181,7 +181,7 b' def supportinternal(repo):'
 def supportarchived(repo):
     # type: (localrepo.localrepository) -> bool
     """True if the archived phase can be used on a repository"""
-    return requirements.INTERNAL_PHASE_REQUIREMENT in repo.requirements
+    return requirements.ARCHIVED_PHASE_REQUIREMENT in repo.requirements
 
 
 def _readroots(repo, phasedefaults=None):

mercurial/requirements.py

@@ -31,6 +31,10 b" SPARSE_REQUIREMENT = b'exp-sparse'"
 # of stripping them
 INTERNAL_PHASE_REQUIREMENT = b'internal-phase'
 
+# Enables the internal phase which is used to hide changesets instead
+# of stripping them
+ARCHIVED_PHASE_REQUIREMENT = b'exp-archived-phase'
+
 # Stores manifest in Tree structure
 TREEMANIFEST_REQUIREMENT = b'treemanifest'
 
@@ -107,6 +111,7 b' WORKING_DIR_REQUIREMENTS = {'
 #
 # note: the list is currently inherited from previous code and miss some relevant requirement while containing some irrelevant ones.
 STREAM_FIXED_REQUIREMENTS = {
+    ARCHIVED_PHASE_REQUIREMENT,
     BOOKMARKS_IN_STORE_REQUIREMENT,
     CHANGELOGV2_REQUIREMENT,
     COPIESSDC_REQUIREMENT,

tests/test-phase-archived.t

@@ -4,7 +4,7 b' Test features and behaviors related to t'
 
   $ cat << EOF >> $HGRCPATH
   > [format]
-  > internal-phase=yes
+  > exp-archived-phase=yes
   > [extensions]
   > strip=
   > [experimental]

tests/test-phases.t

@@ -951,21 +951,28 b' Test for archived phase'
 
 Commit an archived changesets
 
+  $ cd ..
+  $ hg clone --quiet --pull internal-phase archived-phase \
+  > --config format.exp-archived-phase=yes \
+  > --config extensions.phasereport='!' \
+  > --config hooks.txnclose-phase.test=
+
+  $ cd archived-phase
+
   $ echo B > B
   $ hg add B
   $ hg status
   A B
   $ hg --config "phases.new-commit=archived" commit -m "my test archived commit"
-  test-debug-phase: new rev 2:  x -> 32
+  test-debug-phase: new rev 1:  x -> 32
   test-hook-close-phase: 8df5997c3361518f733d1ae67cd3adb9b0eaf125:   -> archived
 
 The changeset is a working parent descendant.
 Per the usual visibility rules, it is made visible.
 
   $ hg log -G -l 3
-  @  changeset:   2:8df5997c3361
+  @  changeset:   1:8df5997c3361
   |  tag:         tip
-  |  parent:      0:4a2df7238c3b
   |  user:        test
   |  date:        Thu Jan 01 00:00:00 1970 +0000
   |  summary:     my test archived commit