diff --git a/mercurial/context.py b/mercurial/context.py
--- a/mercurial/context.py
+++ b/mercurial/context.py
@@ -588,10 +588,6 @@ class changectx(basectx):
 
     def walk(self, match):
         fset = set(match.files())
-        # for dirstate.walk, files=['.'] means "walk the whole tree".
-        # follow that here, too
-        fset.discard('.')
-
         # avoid the entire walk if we're only looking for specific files
         if fset and not match.anypats():
             if util.all(fn in self for fn in fset):
@@ -606,6 +602,9 @@ class changectx(basectx):
                 fset.remove(fn)
             if match(fn):
                 yield fn
+        # for dirstate.walk, files=['.'] means "walk the whole tree".
+        # follow that here, too
+        fset.discard('.')
         for fn in sorted(fset):
             if not self.hasdir(fn):
                 match.bad(fn, _('no such file in rev %s') % self)
diff --git a/tests/test-cat.t b/tests/test-cat.t
--- a/tests/test-cat.t
+++ b/tests/test-cat.t
@@ -22,10 +22,22 @@
   $ hg cat -r 1 b
   1
 
-Test fileset
+Test multiple files
 
   $ echo 3 > c
   $ hg ci -Am addmore c
+  $ hg cat b c
+  1
+  3
+  $ hg cat .
+  1
+  3
+  $ hg cat . c
+  1
+  3
+
+Test fileset
+
   $ hg cat 'set:not(b) or a'
   3
   $ hg cat 'set:c or b'