--- a/hgext/convert/common.py
+++ b/hgext/convert/common.py
@@ -335,7 +335,7 @@
             return
         for i, line in enumerate(fp):
             try:
-                key, value = strutil.rsplit(line[:-1], ' ', 1)
+                key, value = line[:-1].rsplit(' ', 1)
             except ValueError:
                 raise util.Abort(_('syntax error in %s(%d): key/value pair expected')
                                  % (self.path, i+1))

--- a/hgext/convert/subversion.py
+++ b/hgext/convert/subversion.py
@@ -501,7 +501,7 @@
         return int(rev.split('@')[-1])
 
     def revsplit(self, rev):
-        url, revnum = strutil.rsplit(rev.encode(self.encoding), '@', 1)
+        url, revnum = rev.encode(self.encoding).rsplit('@', 1)
         revnum = int(revnum)
         parts = url.split('/', 1)
         uuid = parts.pop(0)[4:]

--- a/mercurial/strutil.py
+++ b/mercurial/strutil.py
@@ -32,10 +32,3 @@
             break
         yield c
         end = c - 1
-
-def rsplit(s, sep=None, maxsplit=-1):
-    try:
-        return s.rsplit(sep, maxsplit)
-    except AttributeError:
-        return [chunk[::-1] for chunk in
-                s[::-1].split(sep, maxsplit)[::-1]]