mercurial/dirstate.py

--- a/mercurial/dirstate.py	Mon Mar 30 12:57:55 2015 -0700
+++ b/mercurial/dirstate.py	Sun Mar 29 23:27:25 2015 -0700
@@ -629,7 +629,7 @@
             j += 1
 
         if not files or '.' in files:
-            files = ['']
+            files = ['.']
         results = dict.fromkeys(subrepos)
         results['.hg'] = None