[PATCH 2 of 3] merge: pass constant cset ancestor to fctx.ancestor

[Peter Arrenbrecht]

# HG changeset patch
# User Peter Arrenbrecht <peter.arrenbrecht at gmail.com>
# Date 1276843764 -7200
merge: pass constant cset ancestor to fctx.ancestor

diff --git a/mercurial/merge.py b/mercurial/merge.py
--- a/mercurial/merge.py
+++ b/mercurial/merge.py
@@ -244,8 +244,13 @@
 def actionkey(a):
     return a[1] == 'r' and -1 or 0, a
 
-def applyupdates(repo, action, wctx, mctx):
-    "apply the merge action list to the working directory"
+def applyupdates(repo, action, wctx, mctx, actx):
+    """apply the merge action list to the working directory
+
+    wctx is the working copy context
+    mctx is the context to be merged into the working copy
+    actx is the context of the common ancestor
+    """
 
     updated, merged, removed, unresolved = 0, 0, 0, 0
     ms = mergestate(repo)
@@ -265,7 +270,7 @@
             repo.ui.debug("preserving %s for resolve of %s\n" % (f, fd))
             fcl = wctx[f]
             fco = mctx[f2]
-            fca = fcl.ancestor(fco) or repo.filectx(f, fileid=nullrev)
+            fca = fcl.ancestor(fco, actx) or repo.filectx(f, fileid=nullrev)
             ms.add(fcl, fco, fca, fd, flags)
             if f != fd and move:
                 moves.append(f)
@@ -506,7 +511,7 @@
         if not partial:
             repo.hook('preupdate', throw=True, parent1=xp1, parent2=xp2)
 
-        stats = applyupdates(repo, action, wc, p2)
+        stats = applyupdates(repo, action, wc, p2, pa)
 
         if not partial:
             repo.dirstate.setparents(fp1, fp2)