[PATCH 4 of 4] transaction: remove the 'onabort' mechanism

[Pierre-Yves David]

# HG changeset patch
# User Pierre-Yves David <pierre-yves.david at fb.com>
# Date 1417729966 28800
#      Thu Dec 04 13:52:46 2014 -0800
# Node ID 980580522580073e8c8e5ea1b7f765dca8abd53a
# Parent  6187b0dbeaf5ce313b6dae85f1f01c3ec67e866f
transaction: remove the 'onabort' mechanism

It has no known users. If someones needs similar functionality, a new 'addabort'
method similar to 'addfinalize' should be added.

diff --git a/mercurial/transaction.py b/mercurial/transaction.py
--- a/mercurial/transaction.py
+++ b/mercurial/transaction.py
@@ -82,20 +82,18 @@ def _playback(journal, report, opener, v
         # only pure backup file remains, it is sage to ignore any error
         pass
 
 class transaction(object):
     def __init__(self, report, opener, vfsmap, journal, after=None,
-                 createmode=None, onabort=None):
+                 createmode=None):
         """Begin a new transaction
 
         Begins a new transaction that allows rolling back writes in the event of
         an exception.
 
         * `after`: called after the transaction has been committed
         * `createmode`: the mode of the journal file that will be created
-        * `onabort`: called as the transaction is aborting, but before any files
-        have been truncated
         """
         self.count = 1
         self.usages = 1
         self.report = report
         # a vfs to the store content
@@ -103,11 +101,10 @@ class transaction(object):
         # a map to access file in various {location -> vfs}
         vfsmap = vfsmap.copy()
         vfsmap[''] = opener  # set default value
         self._vfsmap = vfsmap
         self.after = after
-        self.onabort = onabort
         self.entries = []
         self.map = {}
         self.journal = journal
         self._queue = []
         # a dict of arguments to be passed to hooks
@@ -434,13 +431,10 @@ class transaction(object):
         self.count = 0
         self.usages = 0
         self.file.close()
         self._backupsfile.close()
 
-        if self.onabort is not None:
-            self.onabort()
-
         try:
             if not self.entries and not self._backupentries:
                 if self.journal:
                     self.opener.unlink(self.journal)
                 if self._backupjournal: