mercurial/graphmod.py

--- a/mercurial/graphmod.py	Thu Sep 04 18:19:32 2014 +0200
+++ b/mercurial/graphmod.py	Fri Nov 14 17:37:59 2014 +0000
@@ -199,6 +199,9 @@
     lowestrev = revs.min()
     gpcache = {}
 
+    if repo.ui.configbool('experimental', 'graph-topological', False):
+        revs = list(groupbranchiter(revs, repo.changelog.parentrevs))
+
     for rev in revs:
         ctx = repo[rev]
         parents = sorted(set([p.rev() for p in ctx.parents()