[PATCH 5 of 6 misc] transplant: assert instead of UnboundLocalError on parentrev in .applied()

[Mads Kiilerich]

# HG changeset patch
# User Mads Kiilerich <madski at unity3d.com>
# Date 1366133616 -7200
#      Tue Apr 16 19:33:36 2013 +0200
# Node ID 52bdb665e6938025c57a2d745de1306aa9439a9f
# Parent  8674a2e7d16fb130b0af9c541c663462a54bc454
transplant: assert instead of UnboundLocalError on parentrev in .applied()

There might be implicit reasons it can't happen, but better be more explicit
and make it fail with a more useful assertion ... if it ever should happen.

diff --git a/hgext/transplant.py b/hgext/transplant.py
--- a/hgext/transplant.py
+++ b/hgext/transplant.py
@@ -91,10 +91,12 @@ class transplanter(object):
     def applied(self, repo, node, parent):
         '''returns True if a node is already an ancestor of parent
         or is parent or has already been transplanted'''
+        parentrev = None
         if hasnode(repo, parent):
             parentrev = repo.changelog.rev(parent)
         if hasnode(repo, node):
             rev = repo.changelog.rev(node)
+            assert parentrev is not None, (node, parent)
             reachable = repo.changelog.ancestors([parentrev], rev,
                                                  inclusive=True)
             if rev in reachable:
@@ -105,6 +107,7 @@ class transplanter(object):
                 self.transplants.remove(t)
                 return False
             lnoderev = repo.changelog.rev(t.lnode)
+            assert parentrev is not None, (node, parent)
             if lnoderev in repo.changelog.ancestors([parentrev], lnoderev,
                                                     inclusive=True):
                 return True