--- a/mercurial/cmdutil.py	Mon Jun 22 22:05:10 2015 +0900
+++ b/mercurial/cmdutil.py	Thu Jul 02 22:03:06 2015 +0900
@@ -1272,7 +1272,7 @@
             return parents
         if self.ui.debugflag:
             return [parents[0], self.repo['null']]
-        if parents[0].rev() >= scmutil.intrev(self.repo, ctx.rev()) - 1:
+        if parents[0].rev() >= scmutil.intrev(ctx.rev()) - 1:
             return []
         return parents
 

--- a/mercurial/scmutil.py	Mon Jun 22 22:05:10 2015 +0900
+++ b/mercurial/scmutil.py	Thu Jul 02 22:03:06 2015 +0900
@@ -6,7 +6,7 @@
 # GNU General Public License version 2 or any later version.
 
 from i18n import _
-from mercurial.node import nullrev
+from mercurial.node import nullrev, wdirrev
 import util, error, osutil, revset, similar, encoding, phases
 import pathutil
 import match as matchmod
@@ -662,11 +662,11 @@
             _rcpath = osrcpath()
     return _rcpath
 
-def intrev(repo, rev):
+def intrev(rev):
     """Return integer for a given revision that can be used in comparison or
     arithmetic operation"""
     if rev is None:
-        return len(repo)
+        return wdirrev
     return rev
 
 def revsingle(repo, revspec, default='.'):

--- a/tests/test-log.t	Mon Jun 22 22:05:10 2015 +0900
+++ b/tests/test-log.t	Thu Jul 02 22:03:06 2015 +0900
@@ -1627,6 +1627,7 @@
 
   $ hg log -r 'wdir()'
   changeset:   0:65624cd9070a+
+  parent:      0:65624cd9070a
   user:        test
   date:        [A-Za-z0-9:+ ]+ (re)