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.

revset: do not fall through to revspec for literal: branch (issue4838) If "literal:" is specified, it must not be a revset expression. It should error out with a better message.

hgweb: ensure both foreground and background colors are specified (issue4872) When users configure the default foreground or background color to non-default (black on white) values, several hgweb styles lack contrast for headers and table row items. This patch fixes that by ensuring that where either foreground or background colors are specified, both are specified.

templater: do not pre-evaluate generator keyword at runsymbol (issue4868) It was introduced by e06e9fd2d99f, but the important code was removed by a3c2d9211294. So there was no positive effect other than exhausting memory. The problem spotted by e06e9fd2d99f is that you can't use a generator keyword more than once. For example, in hgweb template, "{child} {child}" doesn't work because the first "{child}" consumes the generator. But as a3c2d9211294 says, the fix was wrong because it could overwrite a callable keyword that returns a generator. Also the fix didn't work for a generator of generator such as "{diff}" keyword. So, the proper fix for that problem would be to not put a generator in a keyword table. Instead, it should be a factory of a generator. Note that this should fix the memory issue in hgweb, but my firefox killed by OOM in place. Be careful to not use a modern web browser to test the issue4868.

merge: drop special parent assignment in the obsolete case We can safely drop this because the very same assignment is enforcement later in the function. Dropping it will make it simpler to extract the default destination logic in its own function.

bundle: use bundle2 if repository uses general delta As bundle1 does not support generaldelta, this would mean recomputing delta at bundle time. This is similar to what we do for strip and shelve and was tracked as issue4865.

parsebundletype: add a comment for future generation

bundle: extend the format of --type to support version and compression We had some basic undocumented support for uncompressed bundle2 support. We now have an official extensible syntax to specify both format type and compression (eg: bzip2-v2). In practice, this changeset introduce the 'v1' and 'v2' identifier to make it possible to combine format and compression. The default format is still 'v1'. We'll care about picking 'v1' or 'v2' in regard with general delta in the next changesets.

hgweb: fix border-radius for standards-based browsers While here, remove an old gecko-specific property, as gecko has supported the unprefixed version for many years.

filemerge: move precheck to before files are written out This is much simpler, and also avoids unnecessary disk IO.

filemerge: move 'merging' output to before file creation This has no visible impact but makes some future work simpler.

filemerge.filemerge: make a tuple containing merge paths on disk We're going to need this same tuple elsewhere.

filemerge: switch trymerge boolean to mergetype enum trymerge = False becomes mergetype = nomerge, and trymerge = True becomes mergetype = fullmerge or mergeonly, depending on whether a premerge happens.

filemerge: add some merge types We're going to turn the 'trymerge' boolean into a 'mergetype' enum with these three possible values.

shelve: restore unshelved dirstate explicitly after aborting transaction Before this patch, "hg unshelve" uses aborting a current transaction to discard temporary changes while unshelving. This assumes that dirstate changes in a transaction scope are kept even after aborting it. But this assumption will be broken by "transactional dirstate". See the wiki page below for detail about it. https://mercurial.selenic.com/wiki/DirstateTransactionPlan This patch explicitly saves shelved dirstate just before aborting current transaction, and restore dirstate with it after aborting by utility function '_aborttransaction()' added by previous patch.

shelve: restore shelved dirstate explicitly after aborting transaction Before this patch, "hg shelve" uses aborting a current transaction to discard temporary changes while shelving. This assumes that dirstate changes in a transaction scope are kept even after aborting it. But this assumption will be broken by "transactional dirstate". See the wiki page below for detail about it. https://mercurial.selenic.com/wiki/DirstateTransactionPlan This patch explicitly saves shelved dirstate just before aborting current transaction, and restore dirstate with it after aborting by utility function '_aborttransaction()' added by previous patch. This patch replaces 'if tr: tr.abort()' by 'lockmod.release(tr)', because the former is already done in '_aborttransaction()' (and the latter has no effect), if current transaction is aborted in it successfully. Otherwise, the latter is enough to trigger aborting.

shelve: add utility to abort current transaction but keep dirstate "hg shelve" and "hg unshelve" use aborting a current transaction to discard temporary changes while (un)shelving. This assumes that dirstate changes in a transaction scope are kept even after aborting it. But this assumption will be broken by "transactional dirstate". See the wiki page below for detail about it. https://mercurial.selenic.com/wiki/DirstateTransactionPlan This patch adds utility function "_aborttransaction()" to abort current transaction but keep dirstate changes for (un)shelving. 'dirstate.invalidate()' just after aborting a transaction should be removed soon by subsequent patch, which writes or discards in-memory dirstate changes at releasing transaction according to the result of it. BTW, there are some other ways below, which (seem to, at first glance) resolve this issue. But this patch chose straightforward way for ease of review and future refactorring. - commit transaction at first, and then rollback it It causes unintentional "dirty read" of running transaction to other processes at committing it. - use dirstateguard to save and restore shelved dirstate After DirstateTransactionPlan, making 'dirstate.write()' write in-memory changes into actual file requires 'transaction.writepending()' while transaction running. It causes meaningless writing other in-memory changes out, even though they are never referred. In addition to it, it isn't desirable that scope of dirstateguard and transaction intersects each other. - get list of files changed from the parent, keep it in memory, and emulate that changes after aborting transaction This additional memory consumption may block aborting transaction in large repository (on small resource environment).

dirstate: split write to write changes into files other than .hg/dirstate '_writedirstate()' is used mainly for "transactional dirstate". See the wiki page below for detail about it. https://mercurial.selenic.com/wiki/DirstateTransactionPlan

bookmarks: use recordchange instead of writing if transaction is active Before this patch, 'bmstore.write()' always write in-memory bookmark changes into '.hg/bookmarks' regardless of transaction activity. If 'bmstore.write()' is invoked inside a transaction and it writes changes into '.hg/bookmarks', then: - original bookmarks aren't restored at failure of that transaction This breaks "all or nothing" policy of the transaction. BTW, "hg rollback" can restore bookmarks successfully even before this patch, because original bookmarks are saved into '.hg/journal.bookmarks' at the beginning of the transaction, and it (actually renamed as '.hg/undo.bookmarks') is used by "hg rollback". - uncommitted bookmark changes are visible to other processes This is a kind of "dirty read" For example, 'rebase.rebase()' implies 'bmstore.write()', and it may be executed inside the transaction of "hg unshelve". Then, intentional aborting at the end of "hg unshelve" transaction doesn't restore original bookmarks (this is obviously a bug). This patch uses 'bmstore.recordchange()' instead of actual writing by 'bmstore._writerepo()', if any transaction is active This patch also removes meaningless restoring bmstore explicitly at the end of "hg shelve". This patch doesn't choose fixing each 'bmstore.write()' callers as like below, because writing similar code here and there is very redundant. before: bmstore.write() after: tr = repo.currenttransaction() if tr: bmstore.recordchange(tr) else: bmstore.write() Even though 'bmstore.write()' itself may have to be discarded by putting bookmark operations into transaction scope, this patch chose fixing it to implement "transactional dirstate" at first.

filemerge: run symlink check for :merge3 Just like :merge, :merge3 doesn't support merging symlinks.

filemerge: print correct name of tool for symlink checks Earlier we'd print ':merge' even if the tool was something else like ':union'. That's clearly a bug.

filemerge: normalize 'internal:foo' names to ':foo' In upcoming patches we're going to present these names in the UI -- it would be good not to present deprecated names.

filemerge: use symlinkcheck for :merge and :union This exposes a couple of bugs, both of which will be fixed in upcoming patches.

filemerge: add a precheck for symlinks This will be used by internal merge tools.

filemerge: call precheck if available In upcoming patches we'll define a precheck function for some merge tools.

filemerge: add a before-merge callback to internal merge tools We're going to separate the pre-merge and merge steps for merge tools. The merge step will be specific to the tool, but the pre-merge step will be common to all merge tools that need it. However, some merge tools run checks *before* the pre-merge step. This callback will allow that to continue to work.

filemerge: indent filemerge.filemerge This will make upcoming patches much easier to review.

test-bundle-type: replace unbundle with debugbundle We now have a convenient command to look at bundle contents, let's use it.

bundle: extract the parsing of the bundle type in a function We are going to introduce significant extensions of the bundle parsing code to support creation of bundle2 through the bundle command. As an early step, we extract the logic in its own function.

changegroup: add version argument to getchangegroup For some obscure reasons (probably upsetting a Greek goddess), getchangegroup did not had a 'version' argument to control the changegroup version. We fixes this to allow cg02 to be used with 'hg bundle' in the future.

changegroup: add version argument to getlocalchangegroup For some obscure reasons (probably upsetting a Greek goddess), getlocalchangegroup did not have a 'version' argument to control the changegroup version. We fix this to allow cg02 to be used with 'hg bundle' in the future.

shelve: bundle using bundle2 if repository is general delta (issue4862) This will prevent expensive delta computation on bundling and is similar to what we do for strip backup.

shelve: move changegroup generation inside writebundle We will generate different changegroup if general delta is enabled so we gather this in the lower level function. There wasn't any good reason to have it in the main code anyway.

shelve: compress on-disk bundle Shelve is using 'HG10UN' bundle for no obvious reason. Changing this to 'HG10BZ' as we do for other bundle stored on disk.

merge with stable

notify: fix fromauthor setting for 'incoming' hook type (issue4194) Set the author field in notification emails for the 'incoming' hook type in addition to 'changegroup' and 'outgoing' types.

templater: protect word() from crashing on out of range negative value The function isn't documented to work with negative values at all, but it does, which can be useful. However, the range check didn't account for this.

commands: add a new debug command to print merge state We're going to be extending the merge state very soon, and this will give us a way to test all that.

merge.mergestate: factor out code to validate v1/v2 records We're going to need this in another place in upcoming patches.

localrepo: prevent wlock from being inherited when a transaction is running Review feedback from Pierre-Yves David. A separate line of work is working to ensure that dirstate writes are written to a separate 'pending' file while a transaction is active. Lock inheritance currently conflicts with that, so dodge the issue by simply preventing inheritance while a transaction is running. Custom merge drivers aren't going to run inside a transaction, so this doesn't affect that.

lock: add a way to prevent locks from being inherited We want to prevent locks from being inherited sometimes (e.g. when there's a currently running transaction, which will break a lot of assumptions we're making in here.)

test-fncache: use args/kwargs for lock wrapper This is annoying to keep up to date, and also just plain unnecessary.

rebase: enable histedit for useful help with it

rebase: suggest help -e histedit Users unfamiliar with an extension should be reading the documentation for the feature, not the command.

rebase: factor out histedit help command

util: use tuple accessor to get accurate st_mtime value (issue4836) Because st.st_mtime is computed as 'sec + 1e-9 * nsec' and double is too narrow to represent nanoseconds, int(st.st_mtime) can be 'sec + 1'. Therefore, that value could be different from the one got by osutils.listdir(). This patch fixes the problem by accessing to raw st_mtime by tuple index. It catches TypeError to fall back to st.st_mtime because our osutil.stat does not support tuple index. In dirstate.normal(), 'st' is always a Python stat, but in dirstate.status(), it can be either a Python stat or an osutil.stat. Thanks to vgatien-baron@janestreet.com for finding the root cause of this subtle problem.

util: extract stub function to get mtime with second accuracy This function is trivial but will need a long comment why it can't use st.st_mtime. See the next patch for details.

scmutil: add a way for a repo's wlock to be inherited by a subprocess This is part of a series that will allow locks to be inherited by subprocesses in limited circumstances. In the future, we'll call this for custom merge drivers.

scmutil: add a way for a subprocess to be run with an inheritable lock This is part of a series that will allow locks to be inherited by subprocesses in limited circumstances. In an upcoming patch, we'll add an API for the wlock to be inherited.

localrepo: add a way to get the current wlock if it's held This will be useful to pass around a reference to the lock to some functions we're going to add to scmutil. We don't want those functions to live in localrepo to avoid bloat.

localrepo: add a way to get the current lock if it's held We'll use this in upcoming patches to return a reference to the wlock if it's held.

test-help: verify that extension keywords appear in help templates fixed by a2291c9c85a1

templatekw: add {changes}, {distance} and {tag} to the {latesttag} keyword

templater: introduce {latesttag()} function to match a pattern (issue4184) This allows the latest class of tag to be found, such as a release candidate or final build, instead of just the absolute latest. It doesn't appear that the existing keyword can be given an optional argument. There is a keyword, function and filter for 'date', so it doesn't seem harmful to introduce a new function with the same name as an existing keyword. Most functions are pretty Mercurial agnostic, but there is {revset()} as precedent. Even though templatekw.getlatesttags() returns a single tuple, one entry of which is a list, it is simplest to present this as a list of tags instead of a single item, with each tag having a distance and change count attribute. It is also closer to how {latesttag} returns a list of tags, and how this function works when not given a '%' operator.

templatekw: introduce showlatesttags() to handle {latesttag} keywords The keywords {changes}, {distance} and {tag} will be available on a future template method that will allow pattern matching against tag names. For consistency, these should be available on the existing {latesttag} keyword as well. I debated whether or not to add {tag} instead of just continuing with the existing {latesttag}. But it seems clearer not to have the same name for two distinct things (a list in the LHS of %, and an individual tag value on the right). The value of latesttags[0] is the date of commit for the cset to which the tag is applied (i.e. not the date the tag was applied), and therefore isn't made visible because it doesn't seem interesting. It appears that this is merely an internal implementation detail for sorting csets in a stable manner when there are different branches.

templatekw: factor out the changessincetag calculation to a private method This will be reused in the next patch.

templatekw: allow getlatesttags() to match a specific tag pattern This will allow the latest class of tag to be found, such as a release candidate or final build, instead of just the absolute latest. It will be exposed in a future patch. It's unfortunate that the original 'latesttags' cache can't be used to determine the proper values, but it isn't fully populated for the entire repo. For example, the {latesttagdistance} keyword on the Mecurial repo builds the cache up back to the revision for 1.4. If the pattern was 're:^0\.\d$', that wouldn't be in the cache. Maybe this can be optimized some other way, but for now, this is the simpliest implementation.

util: extract stringmatcher() from revset This is used to match against tags, bookmarks, etc in revsets. It will be used in a future patch to do the same tag matching in templater.

util.chunkbuffer: avoid extra mutations when reading partial chunks Previously, a read(N) where N was less than the length of the first available chunk would mutate the deque instance twice and allocate a new str from the slice of the existing chunk. Profiling drawed my attention to these as a potential hot spot during changegroup reading. This patch makes the code more complicated in order to avoid the aforementioned 3 operations. On a pre-generated mozilla-central gzip bundle, this series has the following impact on `hg unbundle` performance on my MacBook Pro: before: 358.21 real 317.69 user 38.49 sys after: 301.57 real 262.69 user 37.11 sys delta: -56.64 real -55.00 user -1.38 sys

util.chunkbuffer: refactor chunk handling logic This will make the next patch easier to read. It provides no benefit on its own.

util.chunkbuffer: special case reading everything The new code results in simpler logic within the while loop. It is also faster since we avoid performing operations on the queue and buf collections. However, there shouldn't be any super hot loops for this since the whole point of chunkbuffer is to avoid reading large amounts of data at once. This does, however, make it easier to optimize chunkbuffer in a subsequent patch.

revert: add reference to backout