--- a/hgext3rd/evolve/utility.py	Wed Mar 22 03:15:58 2017 +0100
+++ b/hgext3rd/evolve/utility.py	Sat Mar 18 22:48:26 2017 +0100
@@ -4,7 +4,6 @@
 #
 # This software may be used and distributed according to the terms of the
 # GNU General Public License version 2 or any later version.
-from mercurial import node
 
 def obsexcmsg(ui, message, important=False):
     verbose = ui.configbool('experimental', 'verbose-obsolescence-exchange',
@@ -19,36 +18,3 @@
     if ui.configbool('experimental', 'verbose-obsolescence-exchange', False):
         topic = 'OBSEXC'
     ui.progress(topic, *args, **kwargs)
-
-_depthcache = {}
-def depth(repo, rev):
-    cl = repo.changelog
-    n = cl.node(rev)
-    revdepth = _depthcache.get(n, None)
-    if revdepth is None:
-        p1, p2 = cl.parentrevs(rev)
-        if p1 == node.nullrev:
-            revdepth = 1
-        elif p2 == node.nullrev:
-            revdepth = depth(repo, p1) + 1
-        else:
-            ancs = cl.commonancestorsheads(cl.node(p1), cl.node(p2))
-            depth_p1 = depth(repo, p1)
-            depth_p2 = depth(repo, p2)
-            if not ancs:
-                revdepth = depth_p1 + depth_p2 + 1
-            elif len(ancs) == 1:
-                anc = cl.rev(ancs[0])
-                revdepth = depth_anc = depth(repo, anc)
-                revdepth += depth_p1 - depth_anc
-                revdepth += depth_p2 - depth_anc
-                revdepth += 1
-            else:
-                # multiple ancestors, we pick the highest and search all missing bits
-                anc = max(cl.rev(a) for a in ancs)
-                revdepth = depth(repo, anc)
-                revdepth += len(cl.findmissingrevs(common=[anc], heads=[rev]))
-        _depthcache[n] = revdepth
-    # actual_depth = len(list(cl.ancestors([rev], inclusive=True)))
-    # assert revdepth == actual_depth, (rev, revdepth, actual_depth)
-    return revdepth