diff --git a/mercurial/manifest.py b/mercurial/manifest.py
--- a/mercurial/manifest.py
+++ b/mercurial/manifest.py
@@ -38,8 +38,15 @@ class manifestdict(dict):
                 if flags:
                     ret._flags[fn] = flags
         return ret
-    def flagsdiff(self, d2):
-        return dicthelpers.diff(self._flags, d2._flags, "")
+
+    def diff(self, m2):
+        '''Finds changes between the current manifest and m2. The result is
+        returned as a dict with filename as key and values of the form
+        ((n1,n2),(fl1,fl2)), where n1/n2 is the nodeid in the current/other
+        manifest and fl1/fl2 is the flag in the current/other manifest.'''
+        flagsdiff = dicthelpers.diff(self._flags, m2._flags, "")
+        fdiff = dicthelpers.diff(self, m2)
+        return dicthelpers.join(fdiff, flagsdiff)
 
     def text(self):
         """Get the full data of this manifest as a bytestring."""
diff --git a/mercurial/merge.py b/mercurial/merge.py
--- a/mercurial/merge.py
+++ b/mercurial/merge.py
@@ -10,7 +10,7 @@ import struct
 from node import nullid, nullrev, hex, bin
 from i18n import _
 from mercurial import obsolete
-import error as errormod, util, filemerge, copies, subrepo, worker, dicthelpers
+import error as errormod, util, filemerge, copies, subrepo, worker
 import errno, os, shutil
 
 _pack = struct.pack
@@ -422,11 +422,9 @@ def manifestmerge(repo, wctx, p2, pa, br
 
     aborts = []
     # Compare manifests
-    fdiff = dicthelpers.diff(m1, m2)
-    flagsdiff = m1.flagsdiff(m2)
-    diff12 = dicthelpers.join(fdiff, flagsdiff)
+    diff = m1.diff(m2)
 
-    for f, (n12, fl12) in diff12.iteritems():
+    for f, (n12, fl12) in diff.iteritems():
         if n12:
             n1, n2 = n12
         else: # file contents didn't change, but flags did