diff -r 8ecb17b7f432 -r 517a51d9cd7f hgext/remotefilelog/shallowrepo.py
--- a/hgext/remotefilelog/shallowrepo.py	Fri Dec 28 12:51:47 2018 -0800
+++ b/hgext/remotefilelog/shallowrepo.py	Thu Dec 27 15:19:46 2018 -0800
@@ -143,8 +143,13 @@
             sparse repository.
             '''
             if revs:
-                return sparse.matcher(repo, revs=revs)
-            return sparse.matcher(repo)
+                ret = sparse.matcher(repo, revs=revs)
+            else:
+                ret = sparse.matcher(repo)
+
+            if ret.always():
+                return None
+            return ret
 
         def file(self, f):
             if f[0] == '/':