phase: attach phase to the transaction instead of the lock

phase: attach phase to the transaction instead of the lock

The phase cache file is no longer written on lock release, it is now handled by
the transaction (as changesets and obsolescence markers are).

(Hooray)

As we stop relying on the lock to write phase, repos with no existing phase
information will need to wait for a phase move or a strip to happen in order to
get the first write in the `phaseroots` file. This explain the change in
test-inherit-mode.t.

This should not have any side effects but in very obscure cases where
people interact with pre-2.1 and post-2.1 versions of Mercurial on the
same repo while having MQ patches applied but the MQ extension
disabled from time to time. A case unlikely enough to not be worth
preserving the old behavior with awful hacks.

--- a/mercurial/localrepo.py	Thu Aug 07 14:41:00 2014 -0700
+++ b/mercurial/localrepo.py	Thu Aug 07 14:11:36 2014 -0700
@@ -1089,8 +1089,6 @@
             return l
 
         def unlock():
-            if hasunfilteredcache(self, '_phasecache'):
-                self._phasecache.write()
             for k, ce in self._filecache.items():
                 if k == 'dirstate' or k not in self.__dict__:
                     continue

--- a/mercurial/phases.py	Thu Aug 07 14:41:00 2014 -0700
+++ b/mercurial/phases.py	Thu Aug 07 14:11:36 2014 -0700
@@ -206,11 +206,13 @@
                 fp.write('%i %s\n' % (phase, hex(h)))
         self.dirty = False
 
-    def _updateroots(self, phase, newroots):
+    def _updateroots(self, phase, newroots, tr):
         self.phaseroots[phase] = newroots
         self._phaserevs = None
         self.dirty = True
 
+        tr.addfilegenerator('phase', ('phaseroots',), self._write)
+
     def advanceboundary(self, repo, tr, targetphase, nodes):
         # Be careful to preserve shallow-copied values: do not update
         # phaseroots values, replace them.
@@ -227,7 +229,7 @@
             roots = set(ctx.node() for ctx in repo.set(
                     'roots((%ln::) - (%ln::%ln))', olds, olds, nodes))
             if olds != roots:
-                self._updateroots(phase, roots)
+                self._updateroots(phase, roots, tr)
                 # some roots may need to be declared for lower phases
                 delroots.extend(olds - roots)
             # declare deleted root in the target phase
@@ -250,7 +252,7 @@
             currentroots.update(newroots)
             ctxs = repo.set('roots(%ln::)', currentroots)
             currentroots.intersection_update(ctx.node() for ctx in ctxs)
-            self._updateroots(targetphase, currentroots)
+            self._updateroots(targetphase, currentroots, tr)
         repo.invalidatevolatilesets()
 
     def filterunknown(self, repo):

--- a/tests/test-inherit-mode.t	Thu Aug 07 14:41:00 2014 -0700
+++ b/tests/test-inherit-mode.t	Thu Aug 07 14:11:36 2014 -0700
@@ -120,7 +120,6 @@
   00660 ../push/.hg/store/data/dir/bar.i
   00660 ../push/.hg/store/data/foo.i
   00660 ../push/.hg/store/fncache
-  00660 ../push/.hg/store/phaseroots
   00660 ../push/.hg/store/undo
   00660 ../push/.hg/store/undo.phaseroots
   00660 ../push/.hg/undo.bookmarks