diff --git a/mercurial/scmutil.py b/mercurial/scmutil.py
--- a/mercurial/scmutil.py
+++ b/mercurial/scmutil.py
@@ -418,6 +418,43 @@
     tree = revsetlang.parse(revspec)
     return tree and tree[0] in ('range', 'rangepre', 'rangepost', 'rangeall')
 
+def shortest(revlog, node, minlength):
+    def isvalid(test):
+        try:
+            if revlog._partialmatch(test) is None:
+                return False
+
+            try:
+                i = int(test)
+                # if we are a pure int, then starting with zero will not be
+                # confused as a rev; or, obviously, if the int is larger than
+                # the value of the tip rev
+                if test[0] == '0' or i > len(revlog):
+                    return True
+                return False
+            except ValueError:
+                return True
+        except error.RevlogError:
+            return False
+        except error.WdirUnsupported:
+            # single 'ff...' match
+            return True
+
+    shortest = node
+    startlength = max(6, minlength)
+    length = startlength
+    while True:
+        test = node[:length]
+        if isvalid(test):
+            shortest = test
+            if length == minlength or length > startlength:
+                return shortest
+            length -= 1
+        else:
+            length += 1
+            if len(shortest) <= length:
+                return shortest
+
 def revpair(repo, revs):
     if not revs:
         return repo.dirstate.p1(), None
diff --git a/mercurial/templater.py b/mercurial/templater.py
--- a/mercurial/templater.py
+++ b/mercurial/templater.py
@@ -24,6 +24,7 @@
     registrar,
     revset as revsetmod,
     revsetlang,
+    scmutil,
     templatefilters,
     templatekw,
     util,
@@ -1023,41 +1024,7 @@
     # which would be unacceptably slow. so we look for hash collision in
     # unfiltered space, which means some hashes may be slightly longer.
     cl = mapping['ctx']._repo.unfiltered().changelog
-    def isvalid(test):
-        try:
-            if cl._partialmatch(test) is None:
-                return False
-
-            try:
-                i = int(test)
-                # if we are a pure int, then starting with zero will not be
-                # confused as a rev; or, obviously, if the int is larger than
-                # the value of the tip rev
-                if test[0] == '0' or i > len(cl):
-                    return True
-                return False
-            except ValueError:
-                return True
-        except error.RevlogError:
-            return False
-        except error.WdirUnsupported:
-            # single 'ff...' match
-            return True
-
-    shortest = node
-    startlength = max(6, minlength)
-    length = startlength
-    while True:
-        test = node[:length]
-        if isvalid(test):
-            shortest = test
-            if length == minlength or length > startlength:
-                return shortest
-            length -= 1
-        else:
-            length += 1
-            if len(shortest) <= length:
-                return shortest
+    return scmutil.shortest(cl, node, minlength)
 
 @templatefunc('strip(text[, chars])')
 def strip(context, mapping, args):