merge: remove unnecessary matcher checks As part of changing manifest.diff to accept a matcher, a previous patch added matcher calls to each location in merge.manifestmerge that tested if 'x in mf' to maintain the same behavior as before. After analyzing it further, this matcher call isn't needed, and in fact hurts future patches ability to use the matcher here. Basically, all these 'if x in mf' checks were checking if a matched file's copy source was in the matcher as well. This meant if you passed a matcher for just file foo, it would not return file bar even if foo was a copy of bar. Since manifestmerge cares about copy information, let's allow all lookups of copy sources. We also update one spot with a 'is not None' check, since it wasn't obvious that the value could sometimes be None before, which broke when we called matcher(None). A future patch adds matcher optimizations to manifestmerge which causes this code path to get covered by existing tests.

rebase: use one dirstateguard for entire rebase Recently we switched rebases to run the entire rebase inside a single transaction, which dramatically improved the speed of rebases in repos with large working copies. Let's also move the dirstate into a single dirstateguard to get the same benefits. This let's us avoid serializing the dirstate after each commit. In a large repo, rebasing 27 commits is sped up by about 20%. I believe the test changes are because us touching the dirstate gave the transaction something to actually rollback.

histedit: add histedit.singletransaction config option This adds an option (which defaults to False) to run entire histedits in a single transaction. This results in 20-25% faster histedits in large repos where transaction startup cost is expensive. I didn't want to enable this by default because it has some unfortunate side effects. For instance, if a pretxncommit hook throws midway through the histedit, it will rollback the entire histedit and lose any progress the user had made. Same if the user aborts editting a commit message. It's still worth turning this on for large repos, but probably not for normal sized repos. Long term, once we have inmemory merging, we could do the entire histedit in memory, without a transaction, then we could selectively rollback just parts of it in the event of an exception. Tested it by running the tests with `--extra-config-opt=histedit.singletransaction=True`. The only failure was related to the hook rollback issue I mention above.

histedit: pop action after the action is completed We only want to pop the action after the action is completed, since if the action aborts part way through we want it to remain at the front of the list so continue/abort will start with it. Previously we relied on the fact that we only serialized the state file at the beginning of the action, so the pop wasn't serialized until the next iteration of the loop. In a future patch we will be adding a large transaction around this area, which means if we pop the list early it might get serialized if the action throws a user InterventionRequired error, at which point the action is not in the list anymore. So let's only pop it once the action is really truly done.

histedit: add transaction support to writing the state file This will be used in a future diff to enable a single transaction around an entire histedit.

localrepo: forcibly copy list of filecache keys On Python 3, keys() is more like iterkeys(), so we got in trouble for mutating the dict while we're iterating here. Since the list of caches should be relatively small, work around this difference by just forcing a copy of the key list.

localrepo: turn hook kwargs back into strs before calling hook It might be better to ensure that the hook kwargs dict only has str keys on Python 3. I'm torn.

localrepo: ensure transaction id is fully bytes on py3

dirstate: use future-proof next(iter) instead of iter.next The latter has been removed in Python 3.

posix: tiptoe around tempfile module more delicately Some of the values inside the tempfile calls here are str on Python 3, so we've got to pass str in. Use fsdecode to work around the issue.