pull: reorganize bundle2 argument bundling We are about to add the ability to use stream bundle with bundle2. Before doing so, we need to gather some code that will not be used in the bundle2 case. There is no behavior change within this changeset.

clone: allow bundle2's stream clone with 'server.disablefullbundle' The previous check was a bit too strict and would not recognize a get bundle not requesting changegroup.

bundle2: add support for a 'stream' parameter to 'getbundle' This parameter can be used to request a stream bundle.

bundle2: add a 'stream' part handler for stream cloning The part contains the necessary arguments and payload to handle a stream bundle v2. It will be put to use in later changesets.

streamclone: rework canperformstreamclone There is code about bundle2 laying around in `canperformstreamclone` but not put to any uses. As we discovered with the previous patch, streambundle 'v1' won't work on bundle2 because they are readline based. So we jump to 'v2' as the first expected supported version.

streamclone: define first iteration of version 2 of stream format (This patch is based on a first draft from Gregory Szorc, with deeper rework) Version 1 of the stream clone format was invented many years ago and suffers from a few deficiencies: 1) Filenames are stored in store-encoded (on filesystem) form rather than in their internal form. This makes future compatibility with new store filename encodings more difficult. 2) File entry "headers" consist of a newline of the file name followed by the string file size. Converting strings to integers is avoidable overhead. We can't store filenames with newlines (manifests have this limitation as well, so it isn't a major concern). But the big concern here is the necessity for readline(). Scanning for newlines means reading ahead and that means extra buffer allocations and slicing (in Python) and this makes performance suffer. 3) Filenames aren't compressed optimally. Filenames should be compressed well since there is a lot of repeated data. However, since they are scattered all over the stream (with revlog data in between), they typically fall outside the window size of the compressor and don't compress. 4) It can only exchange stored based content, being able to exchange caches too would be nice. 5) It is limited to a stream-based protocol and isn't suitable for an on-disk format for general repository reading because the offset of individual file entries requires scanning the entire file to find file records. As part of enabling streaming clones to work in bundle2, #2 proved to have a significant negative impact on performance. Since bundle2 provides the opportunity to start fresh, Gregory Szorc figured he would take the opportunity to invent a new streaming clone data format. The new format devised in this series addresses #1, #2, and #4. It punts on #3 because it was complex without yielding a significant gain and on #5 because devising a new store format that "packs" multiple revlogs into a single "packed revlog" is massive scope bloat. However, this v2 format might be suitable for streaming into a "packed revlog" with minimal processing. If it works, great. If not, we can always invent stream format when it is needed. This patch only introduces the bases of the format. We'll get it usable through bundle2 first, then we'll extend the format in future patches to bring it to its full potential (especially #4).

util: implement varint functions This will be useful in an incoming version-2 of the stream format.

util: move 'readexactly' in the util module This function is used in multiple place, having it in util would be better. (existing caller will be migrated in another series)

lfs: separate a debug message from the subsequent abort message

sshserver: add a couple of tests for argument parsing I noticed that we didn't have any unit tests covering wire protocol argument parsing.

merge with stable

wireproto: split streamres into legacy and modern case A couple of commands currently require transmission of uncompressed frames with the old MIME type. Split this case from streamres into a new streamres_legacy class. Streamline the remaining code accordingly. Add a new flag to streamres to request uncompressed streams. This is useful for sending data that is already compressed like a pre-built bundle. Expect clients to support uncompressed data. For older clients, zlib will still be used. Differential Revision: https://phab.mercurial-scm.org/D1862

localrepo: run cache-warming transaction callback before report callback See in-code comment for details. Differential Revision: https://phab.mercurial-scm.org/D1918

scmutil: 0-pad transaction report callback category Before this patch, the transaction name was '%2i-txnreport', which means the first one would be ' 0-txnreport'. It seems more intuitive for sorting purposes (the callbacks are called in lexicographical order) to make it 0-padded. Differential Revision: https://phab.mercurial-scm.org/D1917

stream: add a test showing we also clone bookmarks Bookmarks are not stored in `.hg/store`. We need to make sure they are cloned with `--stream`.

branch: allow changing branch name to existing name if possible With the functionality added in previous patch we can change branches of a revision but not everytime even if it's possible to do so. For example cosider the following case: o 3 added a (foo) o 2 added b (foo) o 1 added c (bar) o 0 added d (bar) Here if I want to change the branch of rev 2,3 to bar, it was not possible and it will say, "a branch with same name exists". This patch allows us to change branch of 2,3 to bar. The underlying logic for changing branch finds the changesets from the revs passed which have no parents in revs. We only support revsets which have only one such root, so to support this we check whether the parent of the root has the same name as that of the new name and if so, we can use the new name to change branches. Differential Revision: https://phab.mercurial-scm.org/D1913

branch: add a --rev flag to change branch name of given revisions This patch adds a new --rev flag to hg branch which can be used to change branch of revisions. This is motivated from topic extension where you can change topic on revisions but this one has few restrictions which are: 1) You cannot change branch name in between the stack 2) You cannot change branch name and set it to an existing name 3) You cannot change branch of non-linear set of commits 4) You cannot change branch of merge commits. Tests are added for the same. .. feature:: An experimental flag `--rev` to `hg branch` which can be used to change branch of changesets. Differential Revision: https://phab.mercurial-scm.org/D1074

templater: fix crash by empty group expression 'exp' may be None because of '(group None)' node. The error message is copied from revset.py.

log: fix typo in comment about _matchfiles()

sparse: --include 'dir1/dir2' should not include 'dir1/*' In 2015 there was a workaround added (f39bace2d6cad32907c0d7961b3c0dbd64a1b7ad) to sparse in the hg-experimental repo. That workaround: a) no longer seems to be needed, since its testcase passes even with the code removed, and b) caused a new problem: --include 'dir1/dir2' ended up including dir1/* too. (--include 'glob:dir1/dir2' is a user-level workaround.) Remove the offending code, and add a testcase for situation B.

fileset: add kind:pat operator ":" isn't taken as a symbol character but an infix operator so we can write e.g. "path:'foo bar'" as well as "'path:foo bar'". An invalid pattern kind is rejected in the former form as we know a kind is specified explicitly. The binding strength is copied from "x:y" range operator of revset. Perhaps it can be adjusted later if we want to parse "foo:bar()" as "(foo:bar)()", not "foo:(bar())". We can also add "kind:" postfix operator if we want. One possible confusion is that the scope of the leading "set:" vs "kind:pat" operator. The former is consumed by a matcher so applies to the whole fileset expression: $ hg files 'set:foo() or kind:bar or baz' ^^^^^^^^^^^^^^^^^^^^^^^^ Whereas the scope of kind:pat operator is narrow: $ hg files 'set:foo() or kind:bar or baz' ^^^

minifileset: unify handling of symbol and string patterns They must be identical for fileset compatibility.

fileset: move import of match module to top Actually there was no circular import issue.

revlog: group delta computation methods under _deltacomputer object Extracting these methods from revlog will allow changing the implementation of the deltacomputer, by providing this interface: __init__(self, revlog) - constructor that initialize the object from a given revlog buildtext(self, revinfo, fh) - builds the fulltext version of a revision from a _revisioninfo object and the file handle to the .d (or .i for inline mode) file. finddeltainfo(self, revinfo, fh) - find a revision in the revlog against which it is acceptable to build a delta, and build the corresponding _deltainfo. It should now be easier to write an experimental feature that would replace _deltacomputer by another object, for example one that would know how to parallelize the delta computation in order to quicken the storage of multiple revisions.

revlog: refactor out _finddeltainfo from _addrevision Splicing the code into smaller chunks should help understanding it, and eventually override some parts in experimental branches to try optimization.

localrepo: micro-optimize __len__() to bypass repoview Since len(changelog) isn't overridden, we don't have to validate a cache of unfiltered changelog. $ python -m timeit -n 10000 \ -s 'from mercurial import hg, ui; repo = hg.repository(ui.ui());' \ 'len(repo)' orig) 10000 loops, best of 3: 32.1 usec per loop new) 10000 loops, best of 3: 1.79 usec per loop Spotted by Jordi Gutiérrez Hermoso.

lfs: defer registering the pre-push hook until blobs are committed The hook searches outgoing commits for blobs, and uploads them before letting the push occur. No reason to search for that which isn't there.

lfs: dump the full response on httperror in debug mode This was immensely helpful in diagnosing the 500: Internal Server Error when using workers to upload. It's a nasty wall of html, so we really can't do anything else with it.

lfs: default the User-Agent header for blob transfers to 'git-lfs' The custom User-Agent for blob transfers was added in e7bb5fc4570c. Now I've hit another incompatibility with a server wanting the string to start with 'git' or 'git-lfs' [1]. I don't feel strongly about this either way, but a Wireshark trace of git shows that when the Batch API is hit, the User-Agent is 'git-lfs/2.3.4'. So this would probably ensure maximum interoperability. This still leaves the experimental knob in, just in case. [1] https://bitbucket.org/sdorra/scm-manager/src/095a027178888bc2b819aebfae3d2c192c858030/scm-plugins/scm-git-plugin/src/main/java/sonia/scm/web/GitUserAgentProvider.java?at=default&fileviewer=file-view-default#GitUserAgentProvider.java-117

lfs: default to not using workers for upload/download I ran into truncated uploads with this defaulting to on. Wojciech Lis diagnosed it as creating keepalive connections prior to forking, and illegally multiplexing the same connection. [1] I didn't notice a problem with the couple of downloads I tried, but disabled both for simplicity and safety. [1] https://www.mercurial-scm.org/pipermail/mercurial-devel/2018-January/109916.html

lfs: add the '{lfsattrs}' template keyword to '{lfs_files}' This provides access to the metadata dictionary contained within the tracked pointer file. The OID is probably the most important attribute, and has its own keyword. But we might as well have this for completeness. I liked {pointer} better, but couldn't make it work with the singular/plural forms.

debugdownload: read repository hgrc if there is one The command does not require a repository, but will use it if there is one. This simplifies the reading of the remote destination when testing for largefile based url.

test-blackbox: stabilize for Windows This goes with 853bf7d90804.

debugdeltachain: cleanup the double call to _slicechunk Follow-up to Yuya's review on 43154a76f3927c4f0c8c6b02be80f0069c7d8fdb: > Nit: hasattr() isn't necessary. revlog._slicechunk() is used in the previous > block. hasattr() isn't necessary indeed, as we are protected by the withsparseread option, which was introduced at the same time as revlog._slicechunk, in e2ad93bcc084b97c48f54c179365376edb702858. And, as Yuya noticed, _slicechunk could be called only once.

blackbox: don't unpack the list while passing into str.join() The current state may result in error TypeError. Caught using evolve-tests.

atomicupdate: add an experimental option to use atomictemp when updating In some cases Mercurial truncating files when updating causes problems. It can happens when processes are currently reading the file or with big file or on NFS mounts. We add an experimental option to use the atomictemp option of vfs.__call__ in order to avoid the problem. The localrepository.wwrite seems to assume the files are created without the `x` flag; with atomictempfile, the new file might inherit the `x` flag from the destination. We force remove it afterward. This code could be refactored and the flag processing could be moved inside vfs. This patch should be tested with `--extra-config-opt experimental.update.atomic-file=True` as we disabled the option by default. Differential Revision: https://phab.mercurial-scm.org/D1882

write: add the possibility to pass keyword argument from batchget to vfs We are going to pass atomictemp keyword argument from merge.baychget to vfs.__call__. Update all the frames to accept **kwargs and pass it to the next function. Differential Revision: https://phab.mercurial-scm.org/D1881

blackbox: if --debug is used, also trace ui.debug() calls Differential Revision: https://phab.mercurial-scm.org/D1880

bdiff: handle the possibility of overflow when computing allocation size Differential Revision: https://phab.mercurial-scm.org/D1904

phabricator: add a template item for linking to a differential review Differential Revision: https://phab.mercurial-scm.org/D1802

githelp: don't reference 3rd party commands for `git show` `hg show` is a Facebook-ism. Reference functionality in core. The logic here isn't terrific. But it is better than nothing. Differential Revision: https://phab.mercurial-scm.org/D1729

githelp: improve help for "reset" The previous help referenced a `hg reset`, which is a Facebook-ism. We convert that to `hg update`. We also recognize --soft. Differential Revision: https://phab.mercurial-scm.org/D1728

githelp: clean up reflog help This referenced commands that don't exist in core. The new help isn't great since it references an experimental extension. But it is better than nothing. While we're here, also add test coverage. Differential Revision: https://phab.mercurial-scm.org/D1727

githelp: replace suggestion of `hg record` `hg record` is deprecated in favor of `hg commit --interactive`. Differential Revision: https://phab.mercurial-scm.org/D1726

githelp: remove reference to tweakdefaults This is a Facebook-ism. Differential Revision: https://phab.mercurial-scm.org/D1725

githelp: recommend `hg import` for `git am` This referenced a third party extension. It doesn't feel appropriate to do that from a core extension. Reference `hg import` instead. Differential Revision: https://phab.mercurial-scm.org/D1724

githelp: improve help for `git add` The old code was referencing record and crecord, which are deprecated. `hg commit --interactive` is the preferred mechanism to use. In addition, there was duplicate code in this function. It has been removed. Tests have been added to cover this function. Differential Revision: https://phab.mercurial-scm.org/D1723

githelp: vendor Facebook authored extension This commit vendors the Facebook-authored "githelp" extension. This extension provides a "githelp" command that can be used to try to convert a `git` command to its Mercurial equivalent. This functionality is useful for Git users learning Mercurial. The extension was copied from the repository at revision 32ceeccb832c433b36e9af8196814b8e5a526775. The following modifications were made: * The "testedwith" value has been changed to match core's conventions. * Support for a custom footer has been removed, as it is Facebook specific. The feature is useful. But the implementation wasn't appropriate for core. * A test referencing "tweakdefaults" has been removed. * Imports changed to match Mercurial's style convention. * Double newlines in test removed. * Pager activation changed to ui.pager(). * Initial line of githelp.py changed to add description of file. The removal of the custom footer code was the only significant source change. The rest were mostly cosmetic. There are still some Facebook-isms in the extension. I'll address these as follow-ups. .. feature:: githelp extension The "githelp" extension provides the ``hg githelp`` command. This command attempts to convert a ``git`` command to its Mercurial equivalent. The extension can be useful to Git users new to Mercurial. Differential Revision: https://phab.mercurial-scm.org/D1722

merge: use public interface ms.localctx instead of ms._local

bookmarks: display the obsfate of hidden revision we create a bookmark on Display the same message we added recently to the filtered error message create a bookmark on an hidden revision. Differential Revision: https://phab.mercurial-scm.org/D1870

update: display the obsfate of hidden revision we update to Display the same message we added recently to the filtered error message when updating to a hidden obsolete changeset. Differential Revision: https://phab.mercurial-scm.org/D1869

evolution: make reporting of new unstable changesets optional This makes it possible to turn off the reporting of unstable changesets (e.g. "1 new orphan changesets"), just in case it's too slow for some users. Anyone who's been using the evolve extension has already been accepting the cost of the reporting, so this is just for the few users who have turned on obsmarkers but not been using the evolve extension (as I believe Facebook has). Differential Revision: https://phab.mercurial-scm.org/D1868

evolution: report new unstable changesets This adds a transaction summary callback that reports the number of new orphan, content-divergent and phase-divergent changesets. The code for reporting it is based on the code from the evolve extension, but simplified a bit. It simply counts the numbers for each kind of instability before and after the transaction. That's obviously not very efficient, but it's easy to reason about, so I'm doing this as a first step that can make us quite confident about the test case changes. We can optimize it later and make sure that the tests are not affected. The code has been used in the evolve extension for a long time and has apparently been sufficiently fast, so it doesn't seem like a pressing issue. Unlike the evolve extension's version of this report, this version applies to all commands (or all transactions run as part of any command, to be exact). Differential Revision: https://phab.mercurial-scm.org/D1867

transaction: register summary callbacks only at start of transaction (BC) We currently register summary callbacks every time localrepo.transaction() is called, so both when the transaction is started and when a nested transaction is created. That seems a little weirdly asymmetric, because the summary callbacks are thus not necessarily registred at the beginning of the outermost transaction, but they are only called when the outermost transaction closes (not when a nested transaction closes). I want to add another summary callback that records the repo state at the beginning of the transaction and compares to that when the transaction closes. However, because of the registration that happens when a nested transaction is created, that would need to go through extra trouble to not overwrite the callback and report the difference from the start time of the innermost transaction to the close of the outermost transaction. Also, the callbacks are registered with a name based on the order they are defined in the registersummarycallback(). For example, if both the "new changesets %s" and the "obsoleted %i changesets" hooks are registered, the first would be called 00-txnreport and the second would be called 01-txnreport. That gets really weird if registersummarycallback() gets called multiple times, because the last one wins, and a depending on which of the two callbacks get registered, we might hypothetically even overwrite on type of callback with another. For example, if when the outer transaction was started, we registered the "new changesets %s" callback first, and when the inner transaction was started, we registered only the "obsoleted %i changesets" callback, then only the latter message would get printed. What makes it hypothetical is that what gets registered depends on the transaction name, and the set of transaction names that we match on for the former latter message is a subset of the set of names we match on for the former. Still, that seems like a bug waiting to happen. That second issue could be solved independently, but the first issue seems enough for me to consider it a bug (affecting developers, not users), so this patch simply drops that extra registration. Note that this affects "hg transplant" in a user-visible way. When "hg transplant" is asked to transplant from a remote repo so it involves a pull, then the outermost transaction name is "transplant" and an inner transaction is created for "pull". That inner transaction is what led us to sometimes report "new changesets %s" from "hg transplant". After this patch, that no longer happens. That seems fine to me. We can make it instead print the message for all "hg transplant" invocations if we want (not just those involving a remote), but I'll leave that for someone else to do if they think it's important. Differential Revision: https://phab.mercurial-scm.org/D1866

repair: filter out unknown revisions from phasecache within transaction I'm about to add another summary report callback that needs to access phase information. These callbacks run at the end of the transaction and some of them failed because they tried to get the phase for stripped commits. The solution is to filter out unknown revisions before the transaction is closed. Differential Revision: https://phab.mercurial-scm.org/D1865

repair: drop unnecessary phase cache invalidation After stripping the revlogs, we have been invalidating the phase cache since bf7b8157c483. Later, in 8e3021fd1a44, I added a call to phasecache.filterunknown(). I apparently didn't realize it then, but I now think that that call made the existing phasecache.invalidate() call unnecessary, so this patch drops it. Both the test added in bf7b8157c483 and the entire evolve extension test suite indeed still pass. Differential Revision: https://phab.mercurial-scm.org/D1864

wireproto: drop support for reader interface from streamres (API) 2add671bf55b and later commits overhauled support for compression and output handling in the wire protocol. Fast forward 14 months and all wire protocol commands except the legacy "changegroup" and "changegroupsubset" commands feed a generator to streamres. I no longer think it is worth maintaining support for the old "reader" API (which allows you to specify an object having a read() method to obtain data). This commit refactors the legacy wire protocol commands to feed a generator to the streamres. We also drop support for the "reader" argument and the code that was using it. As part of the change, chunks over the SSH protocol have increased in size for these commands. But these commands are really ancient, so I doubt anyone will notice. .. api:: wireproto.streamres.__init__ no longer accepts a "reader" argument. Use the "gen" argument instead. Differential Revision: https://phab.mercurial-scm.org/D1861

merge: add `--abort` flag which can abort the merge Currently we don't have a good functionality to abort the merge and tell user to do `hg update -C .` which can leads to different results if user missed the '.' and moreover does not align with other abort functionalities like rebase, shelve etc. This patch adds `hg merge --abort` which will abort the ongoing merge and take us back to the chagneset where we started from. Works in both cases when merge resulted in conflicts and when there were no conflicts. .. feature:: A `--abort` flag to merge command to abort the ongoing merge. Differential Revision: https://phab.mercurial-scm.org/D1829

filemerge: only write in-memory backup during premerge This wasn't broken, but should mirror the non-in memory case to save an extra write. Differential Revision: https://phab.mercurial-scm.org/D1807

filemerge: fix backing up an in-memory file to a custom location If the user specifies a ui.origbackuppath, we used to always copy the file there, but if the source file is in memory we must write it instead of copying. Differential Revision: https://phab.mercurial-scm.org/D1806