strip: do now include internal changeset in the strip backup

See inline comment for details.

tests/test-bundle-phase-internal.t

@@ -0,0 +1,236 b''
+=====================================================
+test behavior of the `internal` phase around bundling
+=====================================================
+
+Long story short, internal changeset are internal implementation details and
+they should never leave the repository. Hence, they should never be in a
+bundle.
+
+Setup
+=====
+
+  $ cat << EOF >> $HGRCPATH
+  > [ui]
+  > logtemplate="{node|short} [{phase}] {desc|firstline}"
+  > EOF
+
+
+  $ hg init reference-repo --config format.use-internal-phase=yes
+  $ cd reference-repo
+  $ echo a > a
+  $ hg add a
+  $ hg commit -m "a"
+  $ echo b > b
+  $ hg add b
+  $ hg commit -m "b"
+  $ echo b > c
+  $ hg add c
+  $ hg commit -m "c"
+  $ hg log -G
+  @  07f0cc02c068 [draft] c
+  |
+  o  d2ae7f538514 [draft] b
+  |
+  o  cb9a9f314b8b [draft] a
+  
+  $ hg up ".^"
+  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
+
+do a shelve
+
+  $ touch a_file.txt
+  $ hg shelve -A
+  adding a_file.txt
+  shelved as default
+  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
+  $ hg log -G --hidden
+  o  2ec3cf310d86 [internal] changes to: b
+  |
+  | o  07f0cc02c068 [draft] c
+  |/
+  @  d2ae7f538514 [draft] b
+  |
+  o  cb9a9f314b8b [draft] a
+  
+  $ shelved_node=`hg log --rev tip --hidden -T '{node|short}'`
+
+add more changeset above it
+
+  $ hg up 'desc(a)'
+  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
+  $ echo d > d
+  $ hg add d
+  $ hg commit -m "d"
+  created new head
+  $ echo d > e
+  $ hg add e
+  $ hg commit -m "e"
+  $ hg up null
+  0 files updated, 0 files merged, 3 files removed, 0 files unresolved
+  $ hg log -G
+  o  636bc07920e3 [draft] e
+  |
+  o  980f7dc84c29 [draft] d
+  |
+  | o  07f0cc02c068 [draft] c
+  | |
+  | o  d2ae7f538514 [draft] b
+  |/
+  o  cb9a9f314b8b [draft] a
+  
+  $ hg log -G --hidden
+  o  636bc07920e3 [draft] e
+  |
+  o  980f7dc84c29 [draft] d
+  |
+  | o  2ec3cf310d86 [internal] changes to: b
+  | |
+  | | o  07f0cc02c068 [draft] c
+  | |/
+  | o  d2ae7f538514 [draft] b
+  |/
+  o  cb9a9f314b8b [draft] a
+  
+  $ cd ..
+
+backup bundle from strip
+========================
+
+strip an ancestors of the internal changeset
+--------------------------------------------
+
+  $ cp -ar reference-repo strip-ancestor
+  $ cd strip-ancestor
+
+The internal change is stripped, yet it should be skipped from the backup bundle.
+
+  $ hg log -G
+  o  636bc07920e3 [draft] e
+  |
+  o  980f7dc84c29 [draft] d
+  |
+  | o  07f0cc02c068 [draft] c
+  | |
+  | o  d2ae7f538514 [draft] b
+  |/
+  o  cb9a9f314b8b [draft] a
+  
+  $ hg debugstrip 'desc(b)'
+  saved backup bundle to $TESTTMP/strip-ancestor/.hg/strip-backup/d2ae7f538514-59bd8bc3-backup.hg
+
+The change should be either gone or hidden
+
+  $ hg log -G
+  o  636bc07920e3 [draft] e
+  |
+  o  980f7dc84c29 [draft] d
+  |
+  o  cb9a9f314b8b [draft] a
+  
+
+The backup should not include it (as people tend to manipulate these directly)
+
+  $ ls -1 .hg/strip-backup/
+  d2ae7f538514-59bd8bc3-backup.hg
+  $ hg debugbundle .hg/strip-backup/*.hg
+  Stream params: {Compression: BZ}
+  changegroup -- {nbchanges: 2, version: 03} (mandatory: True)
+      d2ae7f538514cd87c17547b0de4cea71fe1af9fb
+      07f0cc02c06869c81ebf33867edef30554020c0d
+  cache:rev-branch-cache -- {} (mandatory: False)
+  phase-heads -- {} (mandatory: True)
+      07f0cc02c06869c81ebf33867edef30554020c0d draft
+
+Shelve should still work
+
+  $ hg unshelve
+  unshelving change 'default'
+  rebasing shelved changes
+  $ hg status
+  A a_file.txt
+
+  $ cd ..
+
+strip an unrelated changeset with a lower revnum
+------------------------------------------------
+
+  $ cp -ar reference-repo strip-unrelated
+  $ cd strip-unrelated
+
+The internal change is not directly stripped, but it is affected by the strip
+and it is in the "temporary backup" zone. The zone that needs to be put in a
+temporary bundle while we affect data under it.
+
+  $ hg debugstrip 'desc(c)'
+  saved backup bundle to $TESTTMP/strip-unrelated/.hg/strip-backup/07f0cc02c068-8fd0515f-backup.hg
+
+The change should be either gone or hidden
+
+  $ hg log -G
+  o  636bc07920e3 [draft] e
+  |
+  o  980f7dc84c29 [draft] d
+  |
+  | o  d2ae7f538514 [draft] b
+  |/
+  o  cb9a9f314b8b [draft] a
+  
+The backup should not include it (as people tend to manipulate these directly)
+
+  $ ls -1 .hg/strip-backup/
+  07f0cc02c068-8fd0515f-backup.hg
+  $ hg debugbundle .hg/strip-backup/*.hg
+  Stream params: {Compression: BZ}
+  changegroup -- {nbchanges: 1, version: 03} (mandatory: True)
+      07f0cc02c06869c81ebf33867edef30554020c0d
+  cache:rev-branch-cache -- {} (mandatory: False)
+  phase-heads -- {} (mandatory: True)
+      07f0cc02c06869c81ebf33867edef30554020c0d draft
+
+Shelve should still work
+
+  $ hg unshelve
+  unshelving change 'default'
+  rebasing shelved changes
+  $ hg status
+  A a_file.txt
+
+  $ cd ..
+
+explicitly strip the internal changeset
+---------------------------------------
+
+  $ cp -ar reference-repo strip-explicit
+  $ cd strip-explicit
+
+The internal change is directly selected for stripping.
+
+  $ hg debugstrip --hidden $shelved_node
+
+The change should be gone
+
+  $ hg log -G --hidden
+  o  636bc07920e3 [draft] e
+  |
+  o  980f7dc84c29 [draft] d
+  |
+  | o  07f0cc02c068 [draft] c
+  | |
+  | o  d2ae7f538514 [draft] b
+  |/
+  o  cb9a9f314b8b [draft] a
+  
+
+We don't need to backup anything
+
+  $ ls -1 .hg/strip-backup/
+
+Shelve should still work
+
+  $ hg unshelve
+  unshelving change 'default'
+  rebasing shelved changes
+  $ hg status
+  A a_file.txt
+
+  $ cd ..

mercurial/repair.py

@@ -351,8 +351,14 b' def _createstripbackup(repo, stripbases,'
     vfs = repo.vfs
     unfi = repo.unfiltered()
     to_node = unfi.changelog.node
+    # internal changeset are internal implementation details that should not
+    # leave the repository and not be exposed to the users. In addition feature
+    # using them requires to be resistant to strip. See test case for more
+    # details.
     all_backup = unfi.revs(
-        b"(%ln)::(%ld)", stripbases, unfi.changelog.headrevs()
+        b"(%ln)::(%ld) and not _internal()",
+        stripbases,
+        unfi.changelog.headrevs(),
     )
     if not all_backup:
         return None