hidden: subtract pinned revs from hidden earlier

The pinned revs are simply revisions that should not be hidden even if
hideablerevs() says that should. Let's make that clear by simply
setting "hidden = hideablerevs() - pinnedrevs()" early on.

mercurial/repoview.py

@@ -71,14 +71,13 b' def computehidden(repo):'
 
     hidden = hideablerevs(repo)
     if hidden:
+        hidden = set(hidden - pinnedrevs(repo))
         pfunc = repo.changelog.parentrevs
         mutablephases = (phases.draft, phases.secret)
         mutable = repo._phasecache.getrevset(repo, mutablephases)
 
         visible = set(mutable - hidden)
-        visible |= (hidden & pinnedrevs(repo))
         if visible:
-            hidden = hidden - visible
             _revealancestors(pfunc, hidden, visible)
     return frozenset(hidden)