changeset 6929:972d98ce3552 stable

evolve: unrelated parts of splits are no longer considered content-divergent

Let's backport e68fe567a780 from core that improves content-divergence
computation. This way we can both provide a better experience to evolve
extension users on older Mercurial versions, and don't have to fix evolve tests
for hg 6.1 that we use for one of our CI jobs.

--- a/hgext3rd/evolve/obscache.py	Sat Oct 26 11:16:25 2024 +0400
+++ b/hgext3rd/evolve/obscache.py	Wed Nov 06 16:45:02 2024 +0400
@@ -14,6 +14,7 @@
 from mercurial import (
     localrepo,
     obsolete,
+    obsutil,
     phases,
     node,
     util,
@@ -462,12 +463,45 @@
         isobs = obscache.get
     return frozenset(r for r in notpublic if isobs(r))
 
+def _computecontentdivergentset(repo):
+    """the set of rev that compete to be the final successors of some revision."""
+    divergent = set()
+    obsstore = repo.obsstore
+    newermap = {}
+    tonode = repo.changelog.node
+    candidates = sorted(obsolete._mutablerevs(repo) - obsolete.getrevs(repo, b"obsolete"))
+    for rev in candidates:
+        node = tonode(rev)
+        mark = obsstore.predecessors.get(node, ())
+        toprocess = set(mark)
+        seen = set()
+        while toprocess:
+            prec = toprocess.pop()[0]
+            if prec in seen:
+                continue  # emergency cycle hanging prevention
+            seen.add(prec)
+            if prec not in newermap:
+                obsutil.successorssets(repo, prec, cache=newermap)
+            newer = [n for n in newermap[prec] if n]
+            # only this condition was changed in hg 6.9
+            # hg <= 6.8 (e68fe567a780)
+            if len(newer) > 1 and any(n for n in newer if node not in n):
+                divergent.add(rev)
+                break
+            toprocess.update(obsstore.predecessors.get(prec, ()))
+    return frozenset(divergent)
+
 @eh.uisetup
 def cachefuncs(ui):
     orig = obsolete.cachefuncs[b'obsolete']
     wrapped = lambda repo: _computeobsoleteset(orig, repo)
     obsolete.cachefuncs[b'obsolete'] = wrapped
 
+    if util.versiontuple(n=3) < (6, 8, 2):
+        # e68fe567a780 was just before the 6.8.2 release
+        # hg <= 6.8 (e68fe567a780)
+        obsolete.cachefuncs[b'contentdivergent'] = _computecontentdivergentset
+
 @eh.reposetup
 def setupcache(ui, repo):
 

--- a/tests/test-evolve-templates.t	Sat Oct 26 11:16:25 2024 +0400
+++ b/tests/test-evolve-templates.t	Wed Nov 06 16:45:02 2024 +0400
@@ -1424,7 +1424,7 @@
   working directory parent is obsolete! (4a004186e638)
   (use 'hg evolve' to update to its successor: b18bc8331526)
   $ hg commit --amend -m "Add B only"
-  4 new content-divergent changesets
+  2 new content-divergent changesets
 
   $ hg log -G
   @  changeset:   9:0b997eb7ceee
@@ -1445,7 +1445,7 @@
   | *  changeset:   7:ba2ed02b0c9a
   | |  user:        test
   | |  date:        Thu Jan 01 00:00:00 1970 +0000
-  | |  instability: orphan, content-divergent
+  | |  instability: orphan
   | |  summary:     Add A,B,C
   | |
   | x  changeset:   6:4a004186e638
@@ -1455,11 +1455,10 @@
   |    obsolete:    reworded using amend as 9:0b997eb7ceee
   |    summary:     Add A,B,C
   |
-  *  changeset:   5:dd800401bd8c
+  o  changeset:   5:dd800401bd8c
   |  parent:      3:f897c6137566
   |  user:        test
   |  date:        Thu Jan 01 00:00:00 1970 +0000
-  |  instability: content-divergent
   |  summary:     Add A,B,C
   |
   o  changeset:   3:f897c6137566
@@ -1495,7 +1494,7 @@
   |      Fate: reworded using amend as 8:b18bc8331526
   |      Fate: reworded using amend as 9:0b997eb7ceee
   |
-  *  dd800401bd8c
+  o  dd800401bd8c
   |
   o  f897c6137566
   |
@@ -1513,7 +1512,7 @@
   | x  4a004186e638
   |/     Obsfate: reworded using amend as 8:b18bc8331526; reworded using amend as 9:0b997eb7ceee
   |
-  *  dd800401bd8c
+  o  dd800401bd8c
   |
   o  f897c6137566
   |
@@ -1544,7 +1543,7 @@
   |      Fate: reworded using amend as 9:0b997eb7ceee
   |      Origin: split from 4:9bd10a0775e4
   |
-  *  dd800401bd8c
+  o  dd800401bd8c
   |    Predecessors: 4:9bd10a0775e4
   |    semi-colon: 4:9bd10a0775e4
   |    Origin: split from 4:9bd10a0775e4
@@ -1592,7 +1591,7 @@
   |/     Obsfate: reworded using amend as 8:b18bc8331526; reworded using amend as 9:0b997eb7ceee
   |      Obsorigin: split from 4:9bd10a0775e4
   |
-  *  dd800401bd8c
+  o  dd800401bd8c
   |    Obsorigin: split from 4:9bd10a0775e4
   |
   | x  9bd10a0775e4
@@ -1620,7 +1619,7 @@
   $ hg rebase -r 7 -d 8 --config extensions.rebase=
   rebasing 7:ba2ed02b0c9a "Add A,B,C"
   $ hg tlog
-  *  eceed8f98ffc
+  o  eceed8f98ffc
   |    Predecessors: 4:9bd10a0775e4
   |    semi-colon: 4:9bd10a0775e4
   |    Origin: rewritten using rebase from 4:9bd10a0775e4
@@ -1635,7 +1634,7 @@
   |      semi-colon: 4:9bd10a0775e4
   |      Origin: rewritten using amend from 4:9bd10a0775e4
   |
-  *  dd800401bd8c
+  o  dd800401bd8c
   |    Predecessors: 4:9bd10a0775e4
   |    semi-colon: 4:9bd10a0775e4
   |    Origin: split from 4:9bd10a0775e4
@@ -1651,7 +1650,7 @@
   o  ea207398892e
   
   $ hg fateoriginlog
-  *  eceed8f98ffc
+  o  eceed8f98ffc
   |    Obsorigin: rewritten using rebase from 4:9bd10a0775e4
   |
   | *  0b997eb7ceee
@@ -1660,7 +1659,7 @@
   * |  b18bc8331526
   |/     Obsorigin: rewritten using amend from 4:9bd10a0775e4
   |
-  *  dd800401bd8c
+  o  dd800401bd8c
   |    Obsorigin: split from 4:9bd10a0775e4
   |
   | @  9bd10a0775e4