scmutil: make cleanupnodes delete divergent bookmarks

cleanupnodes takes care of bookmark movement, and bookmark movement could
cause bookmark divergent resolution as a side effect. This patch adds such
bookmark divergent resolution logic so future rebase migration will be
easier.

The revset is carefully written to be equivalent to what rebase does today.
Although I think it might make sense to remove divergent bookmarks more
aggressively, for example:

    F   book@1
    |
    E   book@2
    |
    | D book
    | |
    | C
    |/
    B   book@3
    |
    A

When rebase -s C -d E, "book@1" will be removed, "book@3" will be kept,
and the end result is:

    D   book
    |
    C
    |
    F
    |
    E   book@2 (?)
    |
    B   book@3
    |
    A

The question is should we keep book@2? The current logic keeps it. If we
choose not to (makes some sense to me), the "deleterevs" revset could be
simplified to "newnode % oldnode".

For now, I just make it compatible with the existing behavior. If we want to
make the "deleterevs" revset simpler, we can always do it in the future.

mercurial/scmutil.py

@@ -567,6 +567,16 b' def origpath(ui, repo, filepath):'
 
     return fullorigpath + ".orig"
 
+class _containsnode(object):
+    """proxy __contains__(node) to container.__contains__ which accepts revs"""
+
+    def __init__(self, repo, revcontainer):
+        self._torev = repo.changelog.rev
+        self._revcontains = revcontainer.__contains__
+
+    def __contains__(self, node):
+        return self._revcontains(self._torev(node))
+
 def cleanupnodes(repo, mapping, operation):
     """do common cleanups when old nodes are replaced by new nodes
 
@@ -583,17 +593,16 b' def cleanupnodes(repo, mapping, operatio'
         # Move bookmarks
         bmarks = repo._bookmarks
         bmarkchanged = False
+        allnewnodes = [n for ns in mapping.values() for n in ns]
         for oldnode, newnodes in mapping.items():
             oldbmarks = repo.nodebookmarks(oldnode)
             if not oldbmarks:
                 continue
+            from . import bookmarks # avoid import cycle
             bmarkchanged = True
             if len(newnodes) > 1:
-                heads = list(repo.set('heads(%ln)', newnodes))
-                if len(heads) != 1:
-                    raise error.ProgrammingError(
-                        'cannot figure out bookmark movement')
-                newnode = heads[0].node()
+                # usually a split, take the one with biggest rev number
+                newnode = next(repo.set('max(%ln)', newnodes)).node()
             elif len(newnodes) == 0:
                 # move bookmark backwards
                 roots = list(repo.set('max((::%n) - %ln)', oldnode,
@@ -606,8 +615,13 b' def cleanupnodes(repo, mapping, operatio'
                 newnode = newnodes[0]
             repo.ui.debug('moving bookmarks %r from %s to %s\n' %
                           (oldbmarks, hex(oldnode), hex(newnode)))
+            # Delete divergent bookmarks being parents of related newnodes
+            deleterevs = repo.revs('parents(roots(%ln & (::%n))) - parents(%n)',
+                                   allnewnodes, newnode, oldnode)
+            deletenodes = _containsnode(repo, deleterevs)
             for name in oldbmarks:
                 bmarks[name] = newnode
+                bookmarks.deletedivergent(repo, deletenodes, name)
         if bmarkchanged:
             bmarks.recordchange(tr)
 

tests/test-strip.t

@@ -1002,6 +1002,9 b' Test high-level scmutil.cleanupnodes API'
   $ for i in B C D F G I Z; do
   >     hg bookmark -i -r $i b-$i
   > done
+  $ hg bookmark -i -r E 'b-F@divergent1'
+  $ hg bookmark -i -r H 'b-F@divergent2'
+  $ hg bookmark -i -r G 'b-F@divergent3'
   $ cp -R . ../scmutilcleanup.obsstore
 
   $ cat > $TESTTMP/scmutilcleanup.py <<EOF
@@ -1025,13 +1028,13 b' Test high-level scmutil.cleanupnodes API'
   saved backup bundle to $TESTTMP/scmutilcleanup/.hg/strip-backup/f585351a92f8-73fb7c03-replace.hg (glob)
   
   $ hg log -G -T '{rev}:{node|short} {desc} {bookmarks}' -r 'sort(all(), topo)'
-  o  8:1473d4b996d1 G2 b-G
+  o  8:1473d4b996d1 G2 b-F@divergent3 b-G
   |
   | o  7:d94e89b773b6 F2 b-F
   | |
   | o  5:7fe5bac4c918 H
   |/|
-  | o  3:7fb047a69f22 E
+  | o  3:7fb047a69f22 E b-F@divergent1
   | |
   | | o  6:7c78f703e465 D2 b-D
   | | |
@@ -1048,6 +1051,8 b' Test high-level scmutil.cleanupnodes API'
      b-C                       0:426bada5c675
      b-D                       6:7c78f703e465
      b-F                       7:d94e89b773b6
+     b-F@divergent1            3:7fb047a69f22
+     b-F@divergent3            8:1473d4b996d1
      b-G                       8:1473d4b996d1
      b-I                       0:426bada5c675
      b-Z                       -1:000000000000
@@ -1066,13 +1071,13 b' we have reusable code here'
   
   $ rm .hg/localtags
   $ hg log -G -T '{rev}:{node|short} {desc} {bookmarks}' -r 'sort(all(), topo)'
-  o  12:1473d4b996d1 G2 b-G
+  o  12:1473d4b996d1 G2 b-F@divergent3 b-G
   |
   | o  11:d94e89b773b6 F2 b-F
   | |
   | o  8:7fe5bac4c918 H
   |/|
-  | o  4:7fb047a69f22 E
+  | o  4:7fb047a69f22 E b-F@divergent1
   | |
   | | o  10:7c78f703e465 D2 b-D
   | | |