[PATCH 1 of 8] merge: use nullid instead of nullrev

[Durham Goode]

# HG changeset patch
# User Durham Goode <durham at fb.com>
# Date 1369961254 25200
#      Thu May 30 17:47:34 2013 -0700
# Node ID d6d28e9ca7f60bf791f0b9226804f9010441d88f
# Parent  913d6ce48c5173c5e8f425fa0c776efae454b192
merge: use nullid instead of nullrev

Using nullid instead of nullrev makes it easier to use a filelog implementation
that doesn't have the notion of rev numbers.

diff --git a/mercurial/merge.py b/mercurial/merge.py
--- a/mercurial/merge.py
+++ b/mercurial/merge.py
@@ -452,11 +452,11 @@
                 if fcl.parents():
                     fca = fcl.p1()
                 else:
-                    fca = repo.filectx(f, fileid=nullrev)
+                    fca = repo.filectx(f, fileid=nullid)
             else:
                 fca = fcl.ancestor(fco, actx)
             if not fca:
-                fca = repo.filectx(f, fileid=nullrev)
+                fca = repo.filectx(f, fileid=nullid)
             ms.add(fcl, fco, fca, fd)
             if f != fd and move:
                 moves.append(f)