[PATCH 2 of 5 STABLE V2] bookmarks: resolve divergent bookmarks when moving active bookmark forward

[Sean Farley]

# HG changeset patch
# User Sean Farley <sean.michael.farley at gmail.com>
# Date 1367440485 18000
#      Wed May 01 15:34:45 2013 -0500
# Branch stable
# Node ID e8ae72454bd511afa4cf6b4112c0bbcd51e98823
# Parent  e1a18fe0651e7e04f4bb0c53388c73ac28f754c3
bookmarks: resolve divergent bookmarks when moving active bookmark forward

This patch resolves divergent bookmarks between the current active bookmark
MARK and the new destination. This situation can arise when pulling new
changesets, abandoning your current changesets actively bookmarked with MARK
via strip, and then doing a bare update. The non-divergent but active bookmark
MARK is then moved to a common ancestor of the new changesets and the abandoned
changesets.

Test coverage is added.

diff --git a/mercurial/bookmarks.py b/mercurial/bookmarks.py
--- a/mercurial/bookmarks.py
+++ b/mercurial/bookmarks.py
@@ -169,24 +169,29 @@
                 del marks[mark]
                 deleted = True
     return deleted
 
 def update(repo, parents, node):
+    deletefrom = parents
     marks = repo._bookmarks
     update = False
     cur = repo._bookmarkcurrent
     if not cur:
         return False
 
     if marks[cur] in parents:
         old = repo[marks[cur]]
         new = repo[node]
+        divs = [repo[b] for b in marks
+                if b.split('@', 1)[0] == cur.split('@', 1)[0]]
+        anc = repo.changelog.ancestors([new.rev()])
+        deletefrom = [b.node() for b in divs if b.rev() in anc or b == new]
         if old.descendant(new):
             marks[cur] = new.node()
             update = True
 
-    if deletedivergent(repo, parents, cur):
+    if deletedivergent(repo, deletefrom, cur):
         update = True
 
     if update:
         marks.write()
     return update
diff --git a/tests/test-bookmarks-current.t b/tests/test-bookmarks-current.t
--- a/tests/test-bookmarks-current.t
+++ b/tests/test-bookmarks-current.t
@@ -131,25 +131,31 @@
   $ hg bookmark -i -m Y X
   $ hg bookmarks
      X                         0:719295282060
      Z                         0:719295282060
 
-bare update moves the active bookmark forward
+bare update moves the active bookmark forward and clear the divergent bookmarks
 
   $ echo a > a
   $ hg ci -Am1
   adding a
+  $ echo b >> a
+  $ hg ci -Am2
+  $ hg bookmark X at 1 -r 1
+  $ hg bookmark X at 2 -r 2
   $ hg update X
   0 files updated, 0 files merged, 1 files removed, 0 files unresolved
   $ hg bookmarks
    * X                         0:719295282060
+     X at 1                       1:cc586d725fbe
+     X at 2                       2:49e1c4e84c58
      Z                         0:719295282060
   $ hg update
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
   updating bookmark X
   $ hg bookmarks
-   * X                         1:cc586d725fbe
+   * X                         2:49e1c4e84c58
      Z                         0:719295282060
 
 test deleting .hg/bookmarks.current when explicitly updating
 to a revision