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.

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.