hbisect: pass repo into hbisect.bisect

Pass repo into the bisect function to get more flexibility in what we can call.
This will allow us to use revsets to rewrite parts of the ancestor and children
calculation in later patches.

Test Plan:
    python run-tests.py test-bisect*

Differential Revision: https://phab.mercurial-scm.org/D1497

mercurial/commands.py

@@ -854,7 +854,7 b' def bisect(ui, repo, rev=None, extra=Non'
                 ui.status(_('changeset %d:%s: %s\n') % (ctx, ctx, transition))
                 hbisect.checkstate(state)
                 # bisect
-                nodes, changesets, bgood = hbisect.bisect(repo.changelog, state)
+                nodes, changesets, bgood = hbisect.bisect(repo, state)
                 # update to next check
                 node = nodes[0]
                 mayupdate(repo, node, show_stats=False)
@@ -867,7 +867,7 b' def bisect(ui, repo, rev=None, extra=Non'
     hbisect.checkstate(state)
 
     # actually bisect
-    nodes, changesets, good = hbisect.bisect(repo.changelog, state)
+    nodes, changesets, good = hbisect.bisect(repo, state)
     if extend:
         if not changesets:
             extendnode = hbisect.extendrange(repo, state, nodes, good)

mercurial/hbisect.py

@@ -21,7 +21,7 b' from . import ('
     error,
 )
 
-def bisect(changelog, state):
+def bisect(repo, state):
     """find the next node (if any) for testing during a bisect search.
     returns a (nodes, number, good) tuple.
 
@@ -32,6 +32,7 b' def bisect(changelog, state):'
     if searching for a first bad one.
     """
 
+    changelog = repo.changelog
     clparents = changelog.parentrevs
     skip = set([changelog.rev(n) for n in state['skip']])