[PATCH 1 of 2 V4] manifest: make one use of _mancache avoid manifestctxs

[Durham Goode]

# HG changeset patch
# User Durham Goode <durham at fb.com>
# Date 1473715749 25200
#      Mon Sep 12 14:29:09 2016 -0700
# Node ID 3a45359ff38aee2b4da284186024c3a83cc2b3ae
# Parent  8a658b8b795aaea5e9fe34ae26a49b4656c594cb
manifest: make one use of _mancache avoid manifestctxs

In a future patch we will change manifestctx and treemanifestctx to no longer
derive from manifestdict and treemanifest, respectively. This means that
consumers of the _mancache will now need to be aware of the different between
the two, until we get rid of the manifest entirely and the _mancache becomes
only filled with ctxs.

This fixes one case of it that can be fixed by using the other cache. Future
patches will address the others uses using the upcoming manifestctx.read()
function.

diff --git a/mercurial/bundlerepo.py b/mercurial/bundlerepo.py
--- a/mercurial/bundlerepo.py
+++ b/mercurial/bundlerepo.py
@@ -204,8 +204,8 @@ class bundlemanifest(bundlerevlog, manif
         if isinstance(node, int):
             node = self.node(node)
 
-        if node in self._mancache:
-            result = self._mancache[node].text()
+        if node in self.fulltextcache:
+            result = self.fulltextcache[node].tostring()
         else:
             result = manifest.manifest.revision(self, nodeorrev)
         return result