diff --git a/mercurial/smartset.py b/mercurial/smartset.py
--- a/mercurial/smartset.py
+++ b/mercurial/smartset.py
@@ -1132,7 +1132,10 @@ class fullreposet(_spanset):
             #
             # `other` was used with "&", let's assume this is a set like
             # object.
-            other = baseset(other - self._hiddenrevs)
+            other = baseset(other)
+
+        if self._hiddenrevs:
+            other = other - self._hiddenrevs
 
         other.sort(reverse=self.isdescending())
         return other
diff --git a/tests/test-phases.t b/tests/test-phases.t
--- a/tests/test-phases.t
+++ b/tests/test-phases.t
@@ -1014,8 +1014,6 @@ The hidden commit is an orphan but doesn
      summary:     my test internal commit
   
   $ hg log -G -r 'unstable()'
-  abort: filtered revision '1' (known-bad-output !)
-  [10]
 
 
 Test for archived phase