diff -r c27614f2dec1 -r 854190becacb mercurial/scmutil.py
--- a/mercurial/scmutil.py	Sat Nov 12 03:06:07 2016 +0000
+++ b/mercurial/scmutil.py	Wed Nov 16 23:29:28 2016 -0500
@@ -392,8 +392,7 @@
             newstat = util.filestat(dstpath)
             if newstat.isambig(oldstat):
                 # stat of renamed file is ambiguous to original one
-                advanced = (oldstat.stat.st_mtime + 1) & 0x7fffffff
-                os.utime(dstpath, (advanced, advanced))
+                newstat.avoidambig(dstpath, oldstat)
             return ret
         return util.rename(self.join(src), dstpath)
 
@@ -1460,8 +1459,7 @@
             newstat = util.filestat(self._origfh.name)
             if newstat.isambig(oldstat):
                 # stat of changed file is ambiguous to original one
-                advanced = (oldstat.stat.st_mtime + 1) & 0x7fffffff
-                os.utime(self._origfh.name, (advanced, advanced))
+                newstat.avoidambig(self._origfh.name, oldstat)
 
     def __exit__(self, exc_type, exc_value, exc_tb):
         self._origfh.__exit__(exc_type, exc_value, exc_tb)