--- a/mercurial/store.py	Sat Nov 10 11:47:36 2018 +0900
+++ b/mercurial/store.py	Sat Nov 10 11:52:32 2018 +0900
@@ -427,12 +427,12 @@
 
     def datafiles(self, matcher=None):
         for a, b, size in super(encodedstore, self).datafiles():
-            if not _matchtrackedpath(a, matcher):
-                continue
             try:
                 a = decodefilename(a)
             except KeyError:
                 a = None
+            if a is not None and not _matchtrackedpath(a, matcher):
+                continue
             yield a, b, size
 
     def join(self, f):