[PATCH 2 of 2] revlog: pass node as an argument of addrevision

[Wojciech Lopata]

# HG changeset patch
# User Wojciech Lopata <lopek at fb.com>
# Date 1376936723 25200
#      Mon Aug 19 11:25:23 2013 -0700
# Node ID 568a119612c68959ac44c9ec73c7b50f71c10810
# Parent  ace27c00a18646ce022b5b75448246c1423bde6a
revlog: pass node as an argument of addrevision

This change will allow revlog subclasses that override 'checkhash' method
to use custom strategy of computing nodeids without overriding 'addrevision'
method.

diff --git a/mercurial/revlog.py b/mercurial/revlog.py
--- a/mercurial/revlog.py
+++ b/mercurial/revlog.py
@@ -990,7 +990,8 @@
         tr.replace(self.indexfile, trindex * self._io.size)
         self._chunkclear()
 
-    def addrevision(self, text, transaction, link, p1, p2, cachedelta=None):
+    def addrevision(self, text, transaction, link, p1, p2, cachedelta=None,
+                    node=None):
         """add a revision to the log
 
         text - the revision data to add
@@ -998,11 +999,14 @@
         link - the linkrev data to add
         p1, p2 - the parent nodeids of the revision
         cachedelta - an optional precomputed delta
+        node - nodeid of revision; typically node is not specified, and it is
+            computed by default as hash(text, p1, p2), however subclasses might
+            use different hashing method (and override checkhash() in such case)
         """
         if link == nullrev:
             raise RevlogError(_("attempted to add linkrev -1 to %s")
                               % self.indexfile)
-        node = hash(text, p1, p2)
+        node = node or hash(text, p1, p2)
         if node in self.nodemap:
             return node