localrepo: execute appropriate actions for dirstate at releasing transaction Before this patch, in-memory dirstate changes are still kept over a transaction scope boundary regardless of the result of it. For "all or nothing" policy of the transaction, in-memory dirstate changes should be: - written out at successful closing a transaction, because subsequent 'dirstate.invalidate()' can lose them - discarded at failure of a transaction, because outer 'wlock.release()' or so may write them out To discard all changes in a transaction completely, this patch also restores '.hg/dirstate' by '.hg/journal.dirstate' at failure, because 'transaction' itself does nothing for files related to '.hg/journal.*' in such case (therefore, renaming in this patch is safe enough). This is a part of preparations for "transactional dirstate". See also the wiki page below for detail about it. https://mercurial.selenic.com/wiki/DirstateTransactionPlan This patch also removes redundant 'dirstate.invalidate()' just before aborting a transaction for shelve/unshelve.

transaction: add releasefn to notify the end of a transaction scope 'releasefn' is used by subsequent patch, to do appropriate action according to the result of it at the end of a transaction scope. To ensure that 'releasefn' is invoked only once, this patch invokes it after assignment 'self.journal = None', because such assignment prevents from invoked 'transaction._abort()' again via '__del__()'. def __del__(self): if self.journal: self._abort()

filemerge: move post-merge checks into a separate function This makes the overall filemerge function easier to follow, and makes upcoming work simpler.

filemerge._xmerge: drop no longer necessary 'if r:' check Cleanup from an earlier patch to make premerge be directly called from the main filemerge function.

filemerge._idump: drop no longer necessary 'if r:' check Cleanup from an earlier patch to make premerge be directly called from the main filemerge function.

filemerge._merge: drop no longer necessary 'if r:' check Cleanup from an earlier patch to make premerge be directly called from the main filemerge function.

revset: delete _updatedefaultdest as it has no users The revset is not used anywhere anymore. We delete the function until we use (and therefore test it again).