evolution: stop wrongly flagging unrelated part of a split as divergent

Before this change, divergence introduced by successors of a split would "spill"
to other unrelated successors of the split that were not ambiguous.

This small changes fixes it.

Thanks goes to Manuel Jacobs for the discussion leading to this realization that
a new simple and correct definition could be found.

mercurial/obsolete.py

@@ -1030,7 +1030,9 b' def _computecontentdivergentset(repo):'
             if prec not in newermap:
                 obsutil.successorssets(repo, prec, cache=newermap)
             newer = [n for n in newermap[prec] if n]
-            if len(newer) > 1:
+            # Strickly speaking, the len(newer) is not needed, but it speeds
+            # things up.
+            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, ()))

tests/test-obsmarker-template.t

@@ -2304,7 +2304,7 b' Diverge one of the splitted commit'
   $ hg up 6 --hidden
   0 files updated, 0 files merged, 0 files removed, 0 files unresolved
   $ hg commit --amend -m "Add B only"
-  4 new content-divergent changesets
+  2 new content-divergent changesets
 
   $ hg log -G
   @  changeset:   9:0b997eb7ceee
@@ -2325,7 +2325,7 b' Diverge one of the splitted commit'
   | *  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
@@ -2335,11 +2335,10 b' Diverge one of the splitted commit'
   |    obsolete:    rewritten 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
@@ -2391,7 +2390,7 b' Check templates'
   |      multi-line: 8:b18bc8331526
   |      multi-line: 9:0b997eb7ceee
   |      json: [["b18bc8331526a22cbb1801022bd1555bf291c48b"], ["0b997eb7ceeee06200a02f8aab185979092d514e"]]
-  *  dd800401bd8c
+  o  dd800401bd8c
   |    Predecessors:
   |    semi-colon:
   |    json: []
@@ -2424,7 +2423,7 b' Check templates'
   | |
   | x  4a004186e638
   |/     Obsfate: rewritten using amend as 8:b18bc8331526 by test (at 1970-01-01 00:00 +0000); rewritten using amend as 9:0b997eb7ceee by test (at 1970-01-01 00:00 +0000);
-  *  dd800401bd8c
+  o  dd800401bd8c
   |
   o  f897c6137566
   |
@@ -2464,7 +2463,7 b' Check templates'
   |      multi-line: 8:b18bc8331526
   |      multi-line: 9:0b997eb7ceee
   |      json: [["b18bc8331526a22cbb1801022bd1555bf291c48b"], ["0b997eb7ceeee06200a02f8aab185979092d514e"]]
-  *  dd800401bd8c
+  o  dd800401bd8c
   |    Predecessors: 4:9bd10a0775e4
   |    semi-colon: 4:9bd10a0775e4
   |    json: ["9bd10a0775e478708cada5f176ec6de654359ce7"]
@@ -2522,7 +2521,7 b' Check templates'
   | |
   | x  4a004186e638
   |/     Obsfate: rewritten using amend as 8:b18bc8331526 by test (at 1970-01-01 00:00 +0000); rewritten using amend as 9:0b997eb7ceee by test (at 1970-01-01 00:00 +0000);
-  *  dd800401bd8c
+  o  dd800401bd8c
   |
   | x  9bd10a0775e4
   |/     Obsfate: split as 5:dd800401bd8c, 6:4a004186e638, 7:ba2ed02b0c9a by test (at 1970-01-01 00:00 +0000);
@@ -2543,7 +2542,7 b' Check templates'
   | |
   | x  4a004186e638
   |/     Obsfate: [{"markers": [["4a004186e63889f20cb16434fcbd72220bd1eace", ["b18bc8331526a22cbb1801022bd1555bf291c48b"], 0, [["ef1", "1"], ["operation", "amend"], ["user", "test"]], [0.0, 0], null]], "successors": ["b18bc8331526a22cbb1801022bd1555bf291c48b"]}, {"markers": [["4a004186e63889f20cb16434fcbd72220bd1eace", ["0b997eb7ceeee06200a02f8aab185979092d514e"], 0, [["ef1", "1"], ["operation", "amend"], ["user", "test"]], [0.0, 0], null]], "successors": ["0b997eb7ceeee06200a02f8aab185979092d514e"]}]
-  *  dd800401bd8c
+  o  dd800401bd8c
   |
   | x  9bd10a0775e4
   |/     Obsfate: [{"markers": [["9bd10a0775e478708cada5f176ec6de654359ce7", ["dd800401bd8c79d815329277739e433e883f784e", "4a004186e63889f20cb16434fcbd72220bd1eace", "ba2ed02b0c9a56b9fdbc4e79c7e57866984d8a1f"], 0, [["user", "test"]], [0.0, 0], null]], "successors": ["dd800401bd8c79d815329277739e433e883f784e", "4a004186e63889f20cb16434fcbd72220bd1eace", "ba2ed02b0c9a56b9fdbc4e79c7e57866984d8a1f"]}]
@@ -2562,7 +2561,7 b' Check templates'
   $ 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
   |    json: ["9bd10a0775e478708cada5f176ec6de654359ce7"]
@@ -2586,7 +2585,7 b' Check templates'
   |      Successors:
   |      multi-line:
   |      json: []
-  *  dd800401bd8c
+  o  dd800401bd8c
   |    Predecessors: 4:9bd10a0775e4
   |    semi-colon: 4:9bd10a0775e4
   |    json: ["9bd10a0775e478708cada5f176ec6de654359ce7"]
@@ -2621,13 +2620,13 b' Check templates'
        json: []
 
   $ hg fatelog
-  *  eceed8f98ffc
+  o  eceed8f98ffc
   |
   | *  0b997eb7ceee
   | |
   * |  b18bc8331526
   |/
-  *  dd800401bd8c
+  o  dd800401bd8c
   |
   | @  9bd10a0775e4
   |/     Obsfate: split using amend, rebase as 5:dd800401bd8c, 9:0b997eb7ceee, 10:eceed8f98ffc by test (at 1970-01-01 00:00 +0000); split using amend, rebase as 5:dd800401bd8c, 8:b18bc8331526, 10:eceed8f98ffc by test (at 1970-01-01 00:00 +0000);
@@ -2639,7 +2638,7 b' Check other fatelog implementations'
 -----------------------------------
 
   $ hg fatelogkw --hidden -q
-  *  eceed8f98ffc
+  o  eceed8f98ffc
   |
   | *  0b997eb7ceee
   | |
@@ -2650,7 +2649,7 b' Check other fatelog implementations'
   | x  4a004186e638
   |/     Obsfate: rewritten using amend as 8:b18bc8331526
   |      Obsfate: rewritten using amend as 9:0b997eb7ceee
-  *  dd800401bd8c
+  o  dd800401bd8c
   |
   | @  9bd10a0775e4
   |/     Obsfate: split as 5:dd800401bd8c, 6:4a004186e638, 7:ba2ed02b0c9a
@@ -2664,7 +2663,7 b' Check other fatelog implementations'
   o  ea207398892e
   
   $ hg fatelogkw --hidden
-  *  eceed8f98ffc
+  o  eceed8f98ffc
   |
   | *  0b997eb7ceee
   | |
@@ -2675,7 +2674,7 b' Check other fatelog implementations'
   | x  4a004186e638
   |/     Obsfate: rewritten using amend as 8:b18bc8331526
   |      Obsfate: rewritten using amend as 9:0b997eb7ceee
-  *  dd800401bd8c
+  o  dd800401bd8c
   |
   | @  9bd10a0775e4
   |/     Obsfate: split as 5:dd800401bd8c, 6:4a004186e638, 7:ba2ed02b0c9a
@@ -2689,7 +2688,7 b' Check other fatelog implementations'
   o  ea207398892e
   
   $ hg fatelogkw --hidden -v
-  *  eceed8f98ffc
+  o  eceed8f98ffc
   |
   | *  0b997eb7ceee
   | |
@@ -2700,7 +2699,7 b' Check other fatelog implementations'
   | x  4a004186e638
   |/     Obsfate: rewritten using amend as 8:b18bc8331526 by test (at 1970-01-01 00:00 +0000)
   |      Obsfate: rewritten using amend as 9:0b997eb7ceee by test (at 1970-01-01 00:00 +0000)
-  *  dd800401bd8c
+  o  dd800401bd8c
   |
   | @  9bd10a0775e4
   |/     Obsfate: split as 5:dd800401bd8c, 6:4a004186e638, 7:ba2ed02b0c9a by test (at 1970-01-01 00:00 +0000)
@@ -2714,12 +2713,11 b' Check other fatelog implementations'
   o  ea207398892e
   
   $ hg log -G -T "default" --hidden
-  *  changeset:   10:eceed8f98ffc
+  o  changeset:   10:eceed8f98ffc
   |  tag:         tip
   |  parent:      8:b18bc8331526
   |  user:        test
   |  date:        Thu Jan 01 00:00:00 1970 +0000
-  |  instability: content-divergent
   |  summary:     Add A,B,C
   |
   | *  changeset:   9:0b997eb7ceee
@@ -2749,11 +2747,10 b' Check other fatelog implementations'
   |    obsolete:    rewritten 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
   |
   | @  changeset:   4:9bd10a0775e4

tests/test-obsolete-divergent.t

@@ -466,7 +466,7 b' Check more complex obsolescence graft (w'
   0 files updated, 0 files merged, 1 files removed, 0 files unresolved
   $ hg debugobsolete `getid A_5` `getid A_9`
   1 new obsolescence markers
-  4 new content-divergent changesets
+  3 new content-divergent changesets
   $ hg log -G --hidden
   *  10:bed64f5d2f5a A_9
   |
@@ -480,7 +480,7 b' Check more complex obsolescence graft (w'
   |/
   | x  5:6a411f0d7a0a A_4 [rewritten as 6:e442cfc57690]
   |/
-  | *  4:01f36c5a8fda A_3
+  | o  4:01f36c5a8fda A_3
   |/
   | x  3:392fd25390da A_2 [rewritten as 5:6a411f0d7a0a]
   |/
@@ -553,7 +553,6 b' Check more complex obsolescence graft (w'
   bed64f5d2f5a
       bed64f5d2f5a
   $ hg log -r 'contentdivergent()'
-  4:01f36c5a8fda A_3
   8:7ae126973a96 A_7
   9:14608b260df8 A_8
   10:bed64f5d2f5a A_9
@@ -719,7 +718,58 b' successors-set. (report [A,B] not [A] + '
 
   $ cd ..
 
+Divergence introduced after a split
+-----------------------------------
+
+Make sure divergence introduced in sucessors of a split does not spill to the
+unrelated part.
+
+  $ newcase split-unrelated-branch
+  $ hg debugobsolete `getid A_0` `getid A_1` `getid A_2`
+  1 new obsolescence markers
+  obsoleted 1 changesets
+  $ hg up 'desc("A_2")'
+  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
+  $ hg commit --amend -m "A_3"
+  $ hg up 'desc("A_2")' --hidden
+  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
+  updated to hidden changeset 392fd25390da
+  (hidden revision '392fd25390da' was rewritten as: 4d672202d2fb)
+  $ hg commit --amend -m "A_4" --config experimental.evolution.allowdivergence=yes
+  2 new content-divergent changesets
+  $ hg log -G --hidden
+  @  5:6730f214b07b A_4
+  |
+  | *  4:4d672202d2fb A_3
+  |/
+  | x  3:392fd25390da A_2 [rewritten using amend as 5:6730f214b07b; rewritten using amend as 4:4d672202d2fb]
+  |/
+  | o  2:82623d38b9ba A_1
+  |/
+  | x  1:007dc284c1f8 A_0 [split as 2:82623d38b9ba, 3:392fd25390da]
+  |/
+  o  0:d20a80d4def3 base
+  
+  $ hg debugsuccessorssets --hidden 'desc('A_0')'
+  007dc284c1f8
+      82623d38b9ba 4d672202d2fb
+      82623d38b9ba 6730f214b07b
+  $ hg debugsuccessorssets --hidden 'desc('A_1')'
+  82623d38b9ba
+      82623d38b9ba
+  $ hg debugsuccessorssets --hidden 'desc('A_2')'
+  392fd25390da
+      6730f214b07b
+      4d672202d2fb
+  $ hg log -r 'contentdivergent()'
+  4:4d672202d2fb A_3
+  5:6730f214b07b A_4
+  $ cd ..
+
+
+
 Use scmutil.cleanupnodes API to create divergence
+=================================================
 
   $ hg init cleanupnodes
   $ cd cleanupnodes