dirstate: merge falls through to otherparent

This lets us more correctly fix the state when we use setparents, as
demonstrated in the change in test-graft.t.

mercurial/dirstate.py

@@ -451,11 +451,7 b' class dirstate(object):'
         '''Mark a file merged.'''
         if self._pl[1] == nullid:
             return self.normallookup(f)
-        s = os.lstat(self._join(f))
-        self._addpath(f, 'm', s.st_mode,
-                      s.st_size & _rangemask, int(s.st_mtime) & _rangemask)
-        if f in self._copymap:
-            del self._copymap[f]
+        return self.otherparent(f)
 
     def drop(self, f):
         '''Drop a file from the dirstate'''

tests/test-graft.t

@@ -92,7 +92,7 b' Graft a rename:'
   HG: --
   HG: user: foo
   HG: branch 'default'
-  HG: changed b
+  HG: added b
   HG: removed a
   $ hg export tip --git
   # HG changeset patch

tests/test-merge-remove.t

@@ -22,7 +22,7 b''
 
   $ hg debugstate --nodates
   m   0         -2 bar
-  m 644         14 foo1
+  m   0         -2 foo1
   copy: foo -> foo1
 
   $ hg st -q
@@ -55,8 +55,8 b' Re-adding foo1 and bar:'
   adding foo1
 
   $ hg debugstate --nodates
-  m 644          5 bar
-  m 644         14 foo1
+  n   0         -2 bar
+  n   0         -2 foo1
   copy: foo -> foo1
 
   $ hg st -qC
@@ -74,8 +74,8 b' Reverting foo1 and bar:'
   reverting foo1
 
   $ hg debugstate --nodates
-  m 644          5 bar
-  m 644         14 foo1
+  n   0         -2 bar
+  n   0         -2 foo1
   copy: foo -> foo1
 
   $ hg st -qC