codereview: avoid exception in match

R=rsc
CC=golang-dev
https://golang.org/cl/1585041

diff --git a/lib/codereview/codereview.py b/lib/codereview/codereview.py
index 4b1797a7f01b2fee8643b40db8e2efeb43312b7a..1ece1fa3aed0d88e7c6925d040ea60902530a93d 100644 (file)
--- a/lib/codereview/codereview.py
+++ b/lib/codereview/codereview.py
@@ -659,6 +659,7 @@ original_match = None
 def ReplacementForCmdutilMatch(repo, pats=[], opts={}, globbed=False, default='relpath'):
        taken = []
        files = []
+        pats = pats or []
        for p in pats:
                if p.startswith('@'):
                        taken.append(p)
@@ -671,7 +672,7 @@ def ReplacementForCmdutilMatch(repo, pats=[], opts={}, globbed=False, default='r
                        if cl.files == None:
                                raise util.Abort("no files in CL " + clname)
                        files = Add(files, cl.files)
-       pats = Sub(pats, taken) + ['path:'+f for f in files]
+       pats = Sub(pats, taken) + ['path:'+f for f in files]
        return original_match(repo, pats=pats, opts=opts, globbed=globbed, default=default)
 
 def RelativePath(path, cwd):