transaction: pass the transaction to 'postclose' callback

This mirrors the API for 'pending' and 'finalize' callbacks. I do not have
immediate usage planned for it, but I'm sure some callback will be happy to
access transaction related data.

mercurial/changegroup.py

@@ -816,7 +816,7 b' def addchangegroup(repo, source, srctype'
                             ', '.join([hex(c[:6]) for c in newheads]))
 
             tr.addpostclose('changegroup-runhooks-%020i' % clstart,
-                            lambda: repo._afterlock(runhooks))
+                            lambda tr: repo._afterlock(runhooks))
 
         tr.close()
 

mercurial/exchange.py

@@ -861,7 +861,7 b' class pulloperation(object):'
             def runhooks():
                 repo.hook('b2x-transactionclose', **hookargs)
             self._tr.addpostclose('b2x-hook-transactionclose',
-                                  lambda: repo._afterlock(runhooks))
+                                  lambda tr: repo._afterlock(runhooks))
             self._tr.close()
 
     def releasetransaction(self):
@@ -1286,7 +1286,7 b' def unbundle(repo, cg, heads, source, ur'
                 def runhooks():
                     repo.hook('b2x-transactionclose', **hookargs)
                 tr.addpostclose('b2x-hook-transactionclose',
-                                lambda: repo._afterlock(runhooks))
+                                lambda tr: repo._afterlock(runhooks))
                 tr.close()
             except Exception, exc:
                 exc.duringunbundle2 = True

mercurial/transaction.py

@@ -315,6 +315,8 b' class transaction(object):'
     def addpostclose(self, category, callback):
         """add a callback to be called after the transaction is closed
 
+        The transaction will be given as callback's first argument.
+
         Category is a unique identifier to allow overwriting an old callback
         with a newer callback.
         """
@@ -350,7 +352,7 b' class transaction(object):'
         # run post close action
         categories = sorted(self._postclosecallback)
         for cat in categories:
-            self._postclosecallback[cat]()
+            self._postclosecallback[cat](self)
 
     @active
     def abort(self):