discovery: rename 'error' to 'errormsg' The variable 'error' conflict with the module name that we would like to import and use in a coming changeset.

histedit: delete histedit statefile on any exception during abort When an user aborts a histedit, many things could go wrong. At a minimum, after a histedit abort failure, their repository should be out of that state. We've found situations where the user could not exit the histedit state without manually deleting the histedit state file. This patch ensures that if any exception happens during an abort, the histedit statefile will be deleted so that users are out of the histedit state and can at least manually get the repo back to a workable condition.

histedit: check presence of statefile before deleting it When the histeditstate class instance has it's clear() method called, there is nothing to check to see if the state file exists before deleting it. It may not exist, which would create an exception. This patch allows clear to be called at any time. This will be needed for the following patch.

histedit: add inprogress method to state class If a histedit is progress, the 'histedit-state' file should exist. The patch implements a convenience function to do check if a histedit is in progress. This method will be use in next patch in the series.

commands: use dirstateguard instead of begin/end-parentchange for backout Before this patch, "hg backout" uses 'begin'/'end'-'parentchange()' of 'dirstate' class to avoid writing incomplete dirstate changes out at failure. But this framework doesn't work as expected, if 'dirstate.write()' is invoked between them. In fact, in-memory dirstate changes may be written out at 'repo.status()' implied by 'merge.update()', even before this patch. To restore dirstate as expected at failure of "hg backout", this patch uses 'dirstateguard' instead of 'begin'/'end'-'parentchange()'.

commands: make "hg import" use dirstateguard only for --no-commit Previous patch made dirstate changes in a transaction scope "all or nothing". Therefore, 'dirstateguard' is meaningless, if its scope is as same as one of the related transaction. Before this patch, "hg import" uses 'dirstateguard' always, but transaction is also started if '--no-commit' isn't specified. To avoid redundancy, this patch makes "hg import" use dirstateguard only if transaction isn't started (= '--no-commit' is specified). In this patch, 'if dsguard' can be examined safely, because 'dsguard' is initialized (with None) before outermost 'try'.

cmdutil: stop tryimportone from using dirstateguard (BC) There is no user of 'cmdutil.tryimportone()' other than 'commands.import_()', which can restore dirstate at failure of applying patches by transaction or dirstateguard. Therefore, it is reasonable to stop 'tryimportone()' from using redundant 'dirstateguard', even though it changes behavior of 'tryimportone()'. After this patch, 3rd party extensions should use 'dirstateguard' or so explicitly, if they want to restore dirstate at failure of importing a patch.

dirstate: remove meaningless dirstateguard Previous patch made dirstate changes in a transaction scope "all or nothing". Therefore, 'dirstateguard' is meaningless, if its scope is as same as one of the related transaction. This patch removes such meaningless 'dirstateguard' usage.

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).

merge: get the default update destination from the function There is no value in using the revset instead of the extracted function.

update: move default destination computation to a function We ultimately want this to be accessible through a revset, but there is too much complexity here for that to work. Especially we'll have to return more than just the destination to control the behavior (eg: bookmarks to activate, etc). To prevent cycle, a new module is created, it will receive other destination/behavior function in the future.

worker: restore old countcpus code (issue4869) This is a backout of d29859cfcfc2. The stdlib implementation of multiprocessing.cpu_count() attempts to invoke a process on BSD and Darwin platforms (at least on 2.7). Under certain conditions (such as cwd being removed) this could raise. Our old code was silently catching the exception. The old code was more robust, so restore it.

filemerge: call premerge directly from main merge function The merge code currently does (in pseudocode): for f in tomerge: premerge f merge f We'd like to change this to look more like: for f in tomerge: premerge f for f in tomerge: merge f This makes sure as many files are resolved as possible before prompting for the others. This restructuring is also necessary for custom merge drivers. This function separates out the premerge step from the merge step. In future patches we'll actually turn these into separate steps in the merge driver. The 'if r:' occurrences will be cleaned up in subsequent patches.

bundle2: allow lazily acquiring the lock In the external pushrebase extension, it is valuable to be able to do some work without taking the lock (like running expensive hooks). This enables significantly higher commit throughput. This patch adds an option to lazily acquire the lock. It means that all bundle2 part handlers that require writing to the repo must first call op.gettransction(), when in this mode.

bundle2: add op.gettransaction() to handlers that need the lock A future patch will allow the bundle2 lock be taken lazily. We need to introduce transaction-gets to each handler that needs the lock. The tests caught these issues when I added lazy locking.

merge with stable

patchbomb: add a 'bundletype' config under 'patchbomb' patchbomb relies on the 'hg bundle' command to generate an attached bundle using --bundle. However, while 'hg bundle' has a --type option, patchbomb did not. This is becoming very relevant since we are about to issue bundle2 for general-delta repository. This was tracked as issue4863

import: allow processing of extra part header after import As we have a way for extension to add more header, we need a way for them to actually process them. We add a basic hook point to do extra work after the import have been committed.

import: allow processing of extra part header during import As we have a way for extension to add more header, we need a way for them to actually process them. We add a basic hook points to alter the changeset (especially extra) before we commit. There would be more to do for a full featured hooking, but this currently fit my needs.

extract: parse 'nodeid' using the generic mechanism Parsing 'nodeid' is very simple and a good first test.

extract: parse 'branch' using the generic mechanism Parsing 'branch' is very simple and a good first test.

extract: parse 'date' using the generic mechanism Parsing 'date' is very simple and a good first test.

extract: add some facility for extensible header parsing We need a way for extension to extend the header we can parse. We start with a very simple mechanism that will be used in the next changeset.

extract: remove the 'user' variable It is not heavily used enough to justify being something other than a dictionary entry.

extract: use a single return The differences between both returns are now very thin, we factor out that part.

extract: move 'nodeid' assignment where it is parsed The is one setter and no consumer, we can move it there directly.

extract: move 'date' assignment where it is parsed There is one setter and no consumer, we can move it there directly.

extract: assign user to 'data' earlier This is used in both case, we can assign it once.

extract: move 'branch' assignment where it is parsed There is one setter and no consumer, we can move it there directly.

extract: directly assign parent to data dictionary The temporary variables are not adding anything.

extract: assign message only once This return is shared between the two cases. We can move it earlier.

extract: simplify parents assignement We move to the more standard style of: value = default if special: value = other This is more consistent and compact.

patch: move 'extract' return to a dictionnary The final goal here is to be able to parse, return and process arbitrary data from patch. This mirror the recently added ability to add arbitrary data to patch headers. The first step is to return something more flexible, so we return a dict without changing any other logic.

patchbomb: add experimental config of a "pullurl" and export it This config allows to specify a public location where your changeset can be found. It then include a dedicated patch header show a command to be used to retrieve the change. See the test for example. This is flagged as experimental because this feature is not safe until we have more logic to test that: - changeset actually exists on destination - changeset is draft on destination. As all this is experimental, bike shedding can happily happens before we remove the experimental flag.

export: introduce a generic way to add patch header on export Extensions currently have no easy way to add data to exported patch. This is now fixed using a generic mechanism in the same fashion used by bundle2. Tests are coming in the next changeset with its first user.

incoming: request a bundle2 when possible (BC) Incoming was using bundle1 in all cases, as bundle1 is restricted to changegroup1 and does not support general delta, this can lead to significant CPU overhead if the server is using general delta storage. We now properly request and store a bundle2 to disk. If the server include any output or error in the bundle, they will be stored on disk and replayed when the bundle is read. As 'hg incoming' is going to read the bundle right away, we call that 'good' enough and go back to the bigger plan of having general delta on by default. This was tracked as 4864

bundlerepo: indent some code to prepare next patch We are about to add a new condition. Code is indented in a separated patch for readability.

bundle2: add a way to just forward the bundle2 stream to another user There is use case for directly forward and bundle2 stream from the peer to a file (eg: 'hg incoming --bundle'), However ssh peers have no way to know the 'getbundle' is over except for actually interpreting the bundle. So we need to have the unbundle do the interpreting and forward job. The function is marked as private to highlight that this is terrible and that we are sorry.

bundle2: split parameter retrieval and processing We want to introduce a simple way to forward the content of a bundle2 stream. For this purpose, we will need to both yield the parameters block and process it (to apply any behavior change it might indicate).

changegroup: extract the file management part in its own function The current writebundle function do two things: - taking a changegroup-packer instance and storing it into a valid bundle with proper header. - creating a temporary or requested file to store that bundle We would like to make it easier to forward bundle stream directly from a remote peer to a file, so we split the two logic to be able to skip the one about building a valid bundle (the remote is already sending one).

unbundle: properly read head modification result from bundle2 We were reading the wrong key...

revset: strip off "literal:" prefix from bookmark not found error This is what branch() and tag() do.