smartset: don't ignore hidden revs when intersecting

This fixes the bug I demonstrated in the previous commit, but I'm not sure at
all if it's the right way of doing it.

mercurial/smartset.py

@@ -1132,7 +1132,10 b' 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

tests/test-phases.t

@@ -1014,8 +1014,6 b' 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