localrepo: avoid unnecessary sorting headrevs output already sorted, no need to sort it again.

localrepo: cache self.changelog in local variable Repeated self.changelog lookups can incur overhead. Let's cache it in the separate variable.

destutil: remove dead code about non-linear updates IIUC, the non-linear updates no longer happen by default since 6b1fc09c699a (update: change default destination to tipmost descendant (issue4673) (BC), 2016-02-02), and it was only if they happened by default that we used to error out, so there is no longer a need to handle this case.

update: fix typo/stale comment to match code The comment about "obsolete.background" seems to have been about obsolete.foreground ever since it was introduced in a59e575c6ff8 (update: allow dirty update to foreground (successors), 2013-04-16), so let's change it.

merge: remove unused handling of default destination in merge.update() As far as I can tell, all the callers of merge.update() have been migrated over to use destutil to find the default destination when the revision was not specified. So it's time to delete the code for handling a node value of None. Let's add an assertion that node is not None, so any extensions relying on it will not silently misbehave.

update: localize logic around which ancestor to use The merge code works by applying the changes between an ancestor and the working copy onto the destination. To achieve an update, it sets the ancestor to be the parent of the working copy. To achieve a clean update (update -C), it sets the ancestor to be the working copy itself (so there are no changes to carry over). The logic for this was spread out a bit. Let's move it all to one place so it's easier to follow the reason for it. Also add some documentation.

tests: add test for updating to null revision While working on merge.py, I realized that we don't (as far as I could tell) have any tests for updating to the null revision with a dirty working copy. This adds some simple tests for that.

import: mention "stdin" (abbreviated) and add example I actually didn't even think it was possible because I searched the help text for "stdin", and didn't even think of searching for "standard input". Let's mention the abbreviated form too to help others like me. (When importing from stdin, we actually print a message saying "applying patch from stdin".) This patch also adds an example showing how to import from stdin.

merge: print status message before launching external merge tool It seems somewhat common that people run into a merge conflict and don't notice the launched merge tool, and instead they think hg just hung. Let's print a message for each file that we launch a GUI merge tool for.

pager: exit cleanly on SIGPIPE (BC) Changeset aaa751585325 removes SIGPIPE handling completely. This is wrong, as it means that Mercurial does not exit when the pager does. Instead, raise SignalInterrupt when SIGPIPE happens with a pager attached, to trigger the normal exit path. This will cause "killed!" to be printed to stderr (hence the BC warning), but in the normal pager use case (where the pager gets both stderr and stdout), this message is lost as we only get SIGPIPE when the pager quits.

runtests: catch EPROTONOSUPPORT in checkportisavailable This is a follow-up of "runtests: check ports on IPv6 address". On some platforms, "socket.AF_INET6" exists while that does not necessarily mean the platform support IPv6 - when initializing a socket using "socket.socket", it could fail with EPROTONOSUPPORT. So treat that as "Port unavailable".

zstd: vendor python-zstandard 0.7.0 Commit 3054ae3a66112970a091d3939fee32c2d0c1a23e from https://github.com/indygreg/python-zstandard is imported without modifications (other than removing unwanted files). The vendored zstd library within has been upgraded from 1.1.2 to 1.1.3. This version introduced new APIs for threads, thread pools, multi-threaded compression, and a new dictionary builder (COVER). These features are not yet used by python-zstandard (or Mercurial for that matter). However, that will likely change in the next python-zstandard release (and I think there are opportunities for Mercurial to take advantage of the multi-threaded APIs). Relevant to Mercurial, the CFFI bindings are now fully implemented. This means zstd should "just work" with PyPy (although I haven't tried). The python-zstandard test suite also runs all tests against both the C extension and CFFI bindings to ensure feature parity. There is also a "decompress_content_dict_chain()" API. This was derived from discussions with Yann Collet on list about alternate ways of encoding delta chains. The change most relevant to Mercurial is a performance enhancement in the simple decompression API to reuse a data structure across operations. This makes decompression of multiple inputs significantly faster. (This scenario occurs when reading revlog delta chains, for example.) Using python-zstandard's bench.py to measure the performance difference... On changelog chunks in the mozilla-unified repo: decompress discrete decompress() reuse zctx 1.262243 wall; 1.260000 CPU; 1.260000 user; 0.000000 sys 170.43 MB/s (best of 3) 0.949106 wall; 0.950000 CPU; 0.950000 user; 0.000000 sys 226.66 MB/s (best of 4) decompress discrete dict decompress() reuse zctx 0.692170 wall; 0.690000 CPU; 0.690000 user; 0.000000 sys 310.80 MB/s (best of 5) 0.437088 wall; 0.440000 CPU; 0.440000 user; 0.000000 sys 492.17 MB/s (best of 7) On manifest chunks in the mozilla-unified repo: decompress discrete decompress() reuse zctx 1.367284 wall; 1.370000 CPU; 1.370000 user; 0.000000 sys 274.01 MB/s (best of 3) 1.086831 wall; 1.080000 CPU; 1.080000 user; 0.000000 sys 344.72 MB/s (best of 3) decompress discrete dict decompress() reuse zctx 0.993272 wall; 0.990000 CPU; 0.990000 user; 0.000000 sys 377.19 MB/s (best of 3) 0.678651 wall; 0.680000 CPU; 0.680000 user; 0.000000 sys 552.06 MB/s (best of 5) That should make reads on zstd revlogs a bit faster ;) # no-check-commit

tests: exclude python-zstandard from pyflakes analysis

py3: fix the way we produce bytes list in store.py bytes(range(127)) does not produce a list whereas we need a list. This patch fixes that.

py3: convert os.__file__ to bytes os.__file__ returns unicode path on Python 3. We need to have bytespath. This patch uses pycompat.fsencode() to encode unicode path to bytes path.

commandserver: handle backlog before exiting Previously, when a chg server is exiting, it does not handle connected clients so clients may get ECONNRESET and crash: 1. client connect() # success 2. server shouldexit = True and exit 3. client recv() # ECONNRESET d7875bfbfccb makes this race condition easier to reproduce if a lot of short chg commands are started in parallel. This patch fixes the above issue by unlinking the socket path to stop queuing new connections and processing all pending connections before exit.

misc: replace domain of mercurial-devel ML address by mercurial-scm.org This patch also adds new check-code.py pattern to detect invalid usage of "mercurial-devel@selenic.com".

i18n: update Report-Msgid-Bugs-To property of *.po files This patch replaces domain of mercurial-devel ML address by mercurial-scm.org for "Report-Msgid-Bugs-To" property of each *.po files. This avoids releasing 4.1.1 with invalid "Report-Msgid-Bugs-To" in *.mo file, if corresponded *.po file isn't msgmerge-ed with recent hg.pot by translator. These *.po files aren't covered by check-code.py pattern newly added in subsequent patch, because it ignores them.

misc: replace domain of mercurial ML address by mercurial-scm.org This patch also adds new check-code.py pattern to detect invalid usage of "mercurial@selenic.com". Change for test-convert-tla.t is tested, but similar change for almost same test-convert-baz.t isn't yet tested actually, because I couldn't find out the way to get "GNU Arch baz client". AFAIK, buildbot skips test-convert-baz.t, too. Does anybody have appropriate environment for testing?

commandserver: prevent unlink socket twice This patch changes unixforkingservice so it only calls `self._servicehandler.unlinksocket(self.address)` at most once. This is needed by the next patch.

runtests: check ports on IPv6 address Previously, checkportisavailable only checks ports on the IPv4 address. This patch makes it check IPv6 as well. It'll be useful if "localhost" does not have an IPv4 address, or its IPv4 address does not exist somehow.

zeroconf: fail nicely on IPv6 only system zeroconf only knows how to deal with IPv4; I develop on a system where the only IPv4 address is 127.0.0.1. Teach zeroconf to ignore IPv6 addresses when looking for plausible IPv4 connectivity.

chg: verify XDG_RUNTIME_DIR According to the specification [1], $XDG_RUNTIME_DIR should be ignored unless: The directory MUST be owned by the user, and he MUST be the only one having read and write access to it. Its Unix access mode MUST be 0700. This patch adds a check and ignores it if it does not meet part of the criteria. [1]: https://standards.freedesktop.org/basedir-spec/basedir-spec-latest.html

check-code: permit functools.reduce

perf: split obtaining chunks from decompression Previously, the code was similar to what revlog._chunks() was doing, which took a raw data segment and delta chain, obtained buffers for the raw revlog chunks within, and decompressed them. This commit splits the "get raw chunks" action from "decompress." The goal of this change is to more accurately measurely decompression performance. On a ~50k deltachain for a manifest in mozilla-central: ! full ! wall 0.430548 comb 0.440000 user 0.410000 sys 0.030000 (best of 24) ! deltachain ! wall 0.016053 comb 0.010000 user 0.010000 sys 0.000000 (best of 181) ! read ! wall 0.008078 comb 0.010000 user 0.000000 sys 0.010000 (best of 362) ! rawchunks ! wall 0.033785 comb 0.040000 user 0.040000 sys 0.000000 (best of 100) ! decompress ! wall 0.327126 comb 0.320000 user 0.320000 sys 0.000000 (best of 31) ! patch ! wall 0.032391 comb 0.030000 user 0.030000 sys 0.000000 (best of 100) ! hash ! wall 0.012587 comb 0.010000 user 0.010000 sys 0.000000 (best of 233)

smartset: move set classes and related functions from revset module (API) These classes are pretty large and independent from revset computation. 2961 mercurial/revset.py 973 mercurial/smartset.py 3934 total revset.prettyformatset() is renamed to smartset.prettyformat(). Smartset classes are aliased since they are quite common in revset.py.

help: test if "hg help TOPIC" reference is valid It's quite easy to make a reference invalid by mistake.

help: uppercase command placeholder 'command' isn't a valid help topic but a placeholder text. Make it upper case to avoid confusion.

help: show section that couldn't be found For better error indication.

cmdutil: remove forwarding methods per deprecation policy

util: always force line buffered stdout when stdout is a tty (BC) pager replaced stdout with a line buffered version to work around glibc deciding on a buffering strategy on the first write to stdout. This is going to make my next patch hard, as replacing stdout will make tracking time spent blocked on it more challenging. Move the line buffering requirement to util.py, and remove it from pager. This means that the abuse of ui.formatted=True and pager set to cat or equivalent no longer results in a line-buffered output to a pipe, hence (BC), although I don't expect anyone to be affected

localrepo: avoid unnecessary conversion from node to rev changelog.heads() first calls headrevs then converts them to nodes. localrepo.heads() then sorts them using self.changelog.rev function and makes useless conversion back to revs. Instead let's call changelog.headrevs() from localrepo.heads(), sort the output and then convert to nodes. Because headrevs does not support start parameter this optimization only works if start is None.

debian: update copyright years

debian: update mailing list address

bundle2: implement a basic __repr__ for bundle2 part We display basic data as the part id and part type. This make debugging bundle2 related code friendlier.

bundle2: drop an outdated comment The function is no longer in "early" stage and have been used in production for years. We can probably drop that part of the docstring...

unbundle: swap conditional branches for clarity This is a small style update for clarity. The previous situation was: if foo: 50 lines else: 2 lines In such case I tend to invert these to get the simpler branch out of the way earlier: if not foo: 2 lines else: 50 lines This makes the conditional and various alternatives fit on the same screen, simpler to read overall.

unbundle: add a small comment to tag the bundle1 case as such This makes the code clearer to understand for someone new to it (or rusted)

unbundle: add a small comment to clarify the 'check_heads' call Bundle2 has its own mechanisms to check for heads (and other) changes, so push using bundle2 is relying on the "check:heads" bundle part of unbundle and the 'check_heads' call is not checking anything. We add a small comment to make this clearer.

pager: don't terminate with extreme prejudice on SIGPIPE (BC) The default SIGPIPE handler causes Mercurial to exit immediately, without running any Python cleanup code (except and finally blocks, atexit handlers etc). This creates problems if you want to do something at exit. If we need a different exit code for broken pipe from pager, then we should code that ourselves in Python; this appears to have been cargo-culted from the fork implementation of pager that's no longer used, where it was needed to stop Broken Pipe errors appearing on the user's terminal.

verify: replace _validpath() by matcher The verifier calls out to _validpath() to check if it should verify that path and the narrowhg extension overrides _validpath() to tell the verifier to skip that path. In treemanifest repos, the verifier calls the same method to check if it should visit a directory. However, the decision to visit a directory is different from the condition that it's a matching path, and narrowhg was working around it by returning True from its _validpath() override if *either* was true. Similar to how one can do "hg files -I foo/bar/ -X foo/" (making the include pointless), narrowhg can be configured to track the same paths. In that case match("foo/bar/baz") would be false, but match.visitdir("foo/bar/baz") turns out to be true, causing verify to fail. This may seem like a bug in visitdir(), but it's explicitly documented to be undefined for subdirectories of excluded directories. When using treemanifests, the walk would not descend into foo/, so verification would pass. However, when using flat manifests, there is no recursive directory walk and the file path "foo/bar/baz" would be passed to _validpath() without "foo/" (actually without the slash) being passed first. As explained above, _validpath() would return true for the file path and "hg verify" would fail. Replacing the _validpath() method by a matcher seems like the obvious fix. Narrowhg can then pass in its own matcher and not have to conflate the two matching functions (for dirs and files). I think it also makes the code clearer.

rebase: fix code comment to refer to right issue (4504, not 4505) The comment was introduced in 8a544fb645bb (rebase: ensure rebase revision remains visible (issue4504), 2015-01-27), which mentions the right issue in the description.

merge with stable

Added signature for changeset e1526da1e6d8

Added tag 4.1 for changeset e1526da1e6d8

merge with i18n

i18n-pt_BR: synchronized with dfc6663f97ca

merge: more safe detection of criss cross merge conflict between dm and r 41f6af50c0d8 introduced handling of a crash in this case. A review comment suggested that it was not entirely obvious that a 'dm' always would have a 'r' for the source file. To mitigate that risk, make the code more conservative and make less assumptions.

tests: correct (I think) command in test-largefiles-update When this test was introduced, it used the short-form of all the flags on this update invocation. I suspect, based on the "start with clean dirstates" comment and the fact that the no-exec branch of the #if guard leaves dirstate clean, that this should have been 'update -qCr' instead of 'update -qcr', but that a bug in largefiles --check handling left this problem unnoticed. I'll leave a breadcrumb further up about the current failure mode in the hopes that we can fix this some day. This was previously discussed in [0] but the trail in that thread goes cold after a few replies. Given that this is still a flaky test, that appears to only be passing by bad fortune, I think it's worth correcting the code of the test to make a correct assertion, and to keep track of the suspected bug with some other mechanism than an invalid test (if we had support for "expected failure" blocks this might be a worthwhile use of them?). 0: https://www.mercurial-scm.org/pipermail/mercurial-devel/2016-October/089501.html

tests: expand flags to long form in test-largefiles-update.t I spent some time confused by this test. I'm pretty sure that this line intends to be cleaning the dirstate, not checking that it's clean before updating: the preceding #if block leaves the dirstate clean in the noexec case, and dirty in the exec case, so we can't expect consistent behavior across that platform variation. A subsequent patch will modify this command to use --clean instead of --check. I'll elaborate in that patch about the hypothetical bug here.

merge: fix crash on criss cross merge with dir move and delete (issue5020) Work around that 'dm' in the data model only can have one operation for the target file, but still can have multiple and conflicting operations on the source file where the other operation is a 'rm'. The move would thus fail with 'abort: No such file or directory'. In this case it is "obvious" that the file should be removed, either before or after moving it. We thus keep the 'rm' of the source file but drop the 'dm'. This is not a pretty fix but quite "obviously" safe (famous last words...) as it only touches a rare code path that used to crash. It is possible that it would be better to swap the files for 'dm' as suggested on https://bz.mercurial-scm.org/show_bug.cgi?id=5020#c13 but it is not entirely obvious that it not just would create conflicts on the other file. That can be revisited later.

tests: use 'f' in test-merge-criss-cross.t to prepare for recursive dumping Prepare for adding a test case with files in a directory.

util: make sortdict.keys() return a copy dict.keys() is documented to return a copy, so it's surprising that sortdict.keys() did not. I noticed this because we have an extension that calls readlocaltags(). That method tries to remove any tags that point to non-existent revisions (most likely stripped). However, since it's unintentionally working on the instance it's modifying, it sometimes fails to remove tags when there are multiple bad tags in a row. This was not caught because localrepo.tags() does an additional layer of filtering. sortdict is also used in other places, but I have not checked whether its keys() and/or __delitem__() methods are used there.

test-highlight: add normalization rule for Pygments 2.2 The test failed on Debian sid because of new class="vm".

tests: account for different newline behavior between Solaris and GNU grep GNU grep, when emitting a matching line that doesn't have a terminating newline, will add an extra newline. Solaris grep passes the original line through without the newline. This causes differences in test output when looking at the last line of the output of get-with-headers.py, which doesn't usually emit (and certainly doesn't guarantee) a terminating newline. Both grep implementations succeed in matching the requested pattern, though, so rely on specifying the full pattern on grep's commandline instead of expecting it in the output, and send the output to /dev/null.

tests: also allow "Protocol not supported" in test-http-proxy error I've seen this in a (misconfigured) FreeBSD jail which has ::1 as an entry for localhost, but IPv6 support is disabled in the jail. It took me months to figure out what was going on (and I only figured it out when tinyproxy.py got confused by similar IPv4-level misconfiguration of the localhost domain in /etc/hosts.) I don't feel strongly about this patch: on the one hand, it's papering over a host-level misconfiguration, but on the other it avoids some weird and hard to diagnose problems that can occur in weirdly restricted environments.

revset: prevent using outgoing() and remote() in hgweb session (BC) outgoing() and remote() may stall for long due to network I/O, which seems unsafe per definition, "whether a predicate is safe for DoS attack." But I'm not 100% sure about this. If our concern isn't elapsed time but CPU resource, these predicates are considered safe. Perhaps that would be up to the web/application server configuration? Anyway, outgoing() and remote() wouldn't be useful in hgweb, so I think it's okay to ban them.

tests: use an absolute path to get around '..' being invalid on a dead CWD Only FreeBSD seems to be this picky. Note that this explicit absolute-path `cd` exposes a defect in the test, in that we end up still inside the cwd-vanish repository, but that's not a regression in this change. Since we're in a code freeze, I'm doing the smallest thing possible to try and fix bugs on FreeBSD, rather than cleaning up the entire problem. I'll follow up with a more complete fix after the freeze.

ui: rename tmpdir parameter to more specific repopath This was requested by Augie and I agree that repopath is more descriptive.

pager: wrap _runcommand() no matter if stdout is redirected We've made chg utilize the common code path implemented in pager.py (by 815e1cefd082 and 493935e0327a), but the chg server does not always start with a tty. Because of this, uisetup() of the pager extension could be skipped on the chg server. Kudos given to Sean Farley for dogfooding new chg and spotting this problem.

shelve: make unshelve not crash when there are missing files (issue4176) This patch makes it possible to unshelve while having missing files in your repo as long as shelved changes don't touch those missing files. It also makes error message better otherwise.

statprof: require input file statprof has a __main__ handler that allows viewing of previously written data files. As Yuya pointed out during review, f42cd5434cc2 broke this. This patch fixes that.

tests: work around FreeBSD's unzip having slightly different output According to man 1 unzip, this unzip appeared in FreeBSD 8.0. It's what comes as /usr/bin/unzip, so we may as well cater to it since it's easy.

contrib: fix check-commit to not reject commits from `hg sign` and `hg tag` I'm tired of having a spurious red build every time we do a release. Fix it once and for all.

Added signature for changeset a1dd2c0c479e

Added tag 4.1-rc for changeset a1dd2c0c479e

tests: fix up some http tests for no-zstd case

freeze: merge default into stable for 4.1 code freeze

patchbomb: add tmpdir parameter to ui.edit call

histedit: add tmpdir parameter to ui.edit call

cmdutil: add tmpdir parament to ui.edit calls

ui: add a parameter to set the temporary directory for edit Until callsites are updated, this will have no effect. Once callsites are updated, specifying experimental.editortmpinhg will create editor temporary files in a subdirectory of .hg, which will make it easier for tool integrations to determine what repository is in play when they're asked to edit an hg-related file.

help: update help for `hg update` which was misleading (issue5427)

templater: add '{envvars}' to access environment variables Since the option for ui.exportableenviron is experimental, so is this template until the underlying API is sorted out.

ui: introduce an experimental dict of exportable environment variables Care needs to be taken to prevent leaking potentially sensitive environment variables through hgweb, if template support for environment variables is to be introduced. There are a few ideas about the API for preventing accidental leaking [1]. Option 3 seems best from the POV of not needing to configure anything in the normal case. I couldn't figure out how to do that, so guard it with an experimental option for now. [1] https://www.mercurial-scm.org/pipermail/mercurial-devel/2017-January/092383.html

tests: test experimental.spacemovesdown config for commit -i The feature is still very experimental, but at least its behavior is captured in the test.

zstd: prevent potential free() of uninitialized memory This is a cherry pick of an upstream fix. The free() of uninitialed memory could likely only occur if a malloc() inside zstd fails. The patched functions aren't currently used by Mercurial. But I don't like leaving footguns sitting around.

revlog: give EXTSTORED flag value to narrowhg Narrowhg has been using "1 << 14" as its revlog flag value for a long time. We (Google) have many repos with that value in production already. When the same value was reserved for EXTSTORED, it made those repos invalid. Upgrading them will be a little painful. We should clearly have reserved the value for narrowhg a long time ago. Since the EXTSTORED flag is not yet in any release and Facebook also says they have not started using it in production, so it should be okay to change it. This patch gives the current value (1 << 14) back to narrowhg and gives a new value (1 << 13) to EXTSTORED.

help: don't let tools reflow revlog flags list Before this change, the text about revlog flags was reflowed into a single paragraph, which made it a bit hard to read. I don't even know the rules around this, but adding a blank line before each flag seems to prevent the reflowing.

help: format revlog.txt more closely to result The rendered text has spaces before each item in the list

hgweb: simplify calculation of first revision in filelog command

hgweb: restore ascending iteration on revs in filelog web command Follow-up on 96f811bceb85. Adjust back the "parity" generator's offset to keep rendering the same.

context: extract _changesinrange() out of blockancestors() We'll need it to write a blockdescendants function in next changeset.

shelve: allow multiple shelves with --patch and --stat Before this patch, there was a single way to see multiple shelves using `--patch --list` which show all the shelves. Doing `--patch s1 s2` returns an error. This patch allows to show multiple shelves using `--patch` and `--stat`.

zstd: vendor python-zstandard 0.6.0 Commit 63c68d6f5fc8de4afd9bde81b13b537beb4e47e8 from https://github.com/indygreg/python-zstandard is imported without modifications (other than removing unwanted files). This includes minor performance and feature improvements. It also changes the vendored zstd library from 1.1.1 to 1.1.2. # no-check-commit

util: add length argument to util.buffer() util.buffer() either returns inbuilt buffer function or defines a new one which slices. The inbuilt buffer() also has a length argument which is missing from the ones we defined. This patch adds that length argument.

py3: replace pycompat.getenv with encoding.environ.get pycompat.getenv returns os.getenvb on py3 which is not available on Windows. This patch replaces them with encoding.environ.get and checks to ensure no new instances of os.getenv or os.setenv are introduced.

patch: check length of git index header only if integer is specified Otherwise TypeError would be raised. Follows up d1901c4c8ec0.

localrepo: experimental support for non-zlib revlog compression The final part of integrating the compression manager APIs into revlog storage is the plumbing for repositories to advertise they are using non-zlib storage and for revlogs to instantiate a non-zlib compression engine. The main intent of the compression manager work was to zstd all of the things. Adding zstd to revlogs has proved to be more involved than other places because revlogs are... special. Very small inputs and the use of delta chains (which are themselves a form of compression) are a completely different use case from streaming compression, which bundles and the wire protocol employ. I've conducted numerous experiments with zstd in revlogs and have yet to formalize compression settings and a storage architecture that I'm confident I won't regret later. In other words, I'm not yet ready to commit to a new mechanism for using zstd - or any other compression format - in revlogs. That being said, having some support for zstd (and other compression formats) in revlogs in core is beneficial. It can allow others to conduct experiments. This patch introduces *highly experimental* support for non-zlib compression formats in revlogs. Introduced is a config option to control which compression engine to use. Also introduced is a namespace of "exp-compression-*" requirements to denote support for non-zlib compression in revlogs. I've prefixed the namespace with "exp-" (short for "experimental") because I'm not confident of the requirements "schema" and in no way want to give the illusion of supporting these requirements in the future. I fully intend to drop support for these requirements once we figure out what we're doing with zstd in revlogs. A good portion of the patch is teaching the requirements system about registered compression engines and passing the requested compression engine as an opener option so revlogs can instantiate the proper compression engine for new operations. That's a verbose way of saying "we can now use zstd in revlogs!" On an `hg pull` conversion of the mozilla-unified repo with no extra redelta settings (like aggressivemergedeltas), we can see the impact of zstd vs zlib in revlogs: $ hg perfrevlogchunks -c ! chunk ! wall 2.032052 comb 2.040000 user 1.990000 sys 0.050000 (best of 5) ! wall 1.866360 comb 1.860000 user 1.820000 sys 0.040000 (best of 6) ! chunk batch ! wall 1.877261 comb 1.870000 user 1.860000 sys 0.010000 (best of 6) ! wall 1.705410 comb 1.710000 user 1.690000 sys 0.020000 (best of 6) $ hg perfrevlogchunks -m ! chunk ! wall 2.721427 comb 2.720000 user 2.640000 sys 0.080000 (best of 4) ! wall 2.035076 comb 2.030000 user 1.950000 sys 0.080000 (best of 5) ! chunk batch ! wall 2.614561 comb 2.620000 user 2.580000 sys 0.040000 (best of 4) ! wall 1.910252 comb 1.910000 user 1.880000 sys 0.030000 (best of 6) $ hg perfrevlog -c -d 1 ! wall 4.812885 comb 4.820000 user 4.800000 sys 0.020000 (best of 3) ! wall 4.699621 comb 4.710000 user 4.700000 sys 0.010000 (best of 3) $ hg perfrevlog -m -d 1000 ! wall 34.252800 comb 34.250000 user 33.730000 sys 0.520000 (best of 3) ! wall 24.094999 comb 24.090000 user 23.320000 sys 0.770000 (best of 3) Only modest wins for the changelog. But manifest reading is significantly faster. What's going on? One reason might be data volume. zstd decompresses faster. So given more bytes, it will put more distance between it and zlib. Another reason is size. In the current design, zstd revlogs are *larger*: debugcreatestreamclonebundle (size in bytes) zlib: 1,638,852,492 zstd: 1,680,601,332 I haven't investigated this fully, but I reckon a significant cause of larger revlogs is that the zstd frame/header has more bytes than zlib's. For very small inputs or data that doesn't compress well, we'll tend to store more uncompressed chunks than with zlib (because the compressed size isn't smaller than original). This will make revlog reading faster because it is doing less decompression. Moving on to bundle performance: $ hg bundle -a -t none-v2 (total CPU time) zlib: 102.79s zstd: 97.75s So, marginal CPU decrease for reading all chunks in all revlogs (this is somewhat disappointing). $ hg bundle -a -t <engine>-v2 (total CPU time) zlib: 191.59s zstd: 115.36s This last test effectively measures the difference between zlib->zlib and zstd->zstd for revlogs to bundle. This is a rough approximation of what a server does during `hg clone`. There are some promising results for zstd. But not enough for me to feel comfortable advertising it to users. We'll get there...

revlog: use compression engine APIs for decompression Now that compression engines declare their header in revlog chunks and can decompress revlog chunks, we refactor revlog.decompress() to use them. Making full use of the property that revlog compressor objects are reusable, revlog instances now maintain a dict mapping an engine's revlog header to a compressor object. This is not only a performance optimization for engines where compressor object reuse can result in better performance, but it also serves as a cache of header values so we don't need to perform redundant lookups against the compression engine manager. (Yes, I measured and the overhead of a function call versus a dict lookup was observed.) Replacing the previous inline lookup table with a dict lookup was measured to make chunk reading ~2.5% slower on changelogs and ~4.5% slower on manifests. So, the inline lookup table has been mostly preserved so we don't lose performance. This is unfortunate. But many decompression operations complete in microseconds, so Python attribute lookup, dict lookup, and function calls do matter. The impact of this change on mozilla-unified is as follows: $ hg perfrevlogchunks -c ! chunk ! wall 1.953663 comb 1.950000 user 1.920000 sys 0.030000 (best of 6) ! wall 1.946000 comb 1.940000 user 1.910000 sys 0.030000 (best of 6) ! chunk batch ! wall 1.791075 comb 1.800000 user 1.760000 sys 0.040000 (best of 6) ! wall 1.785690 comb 1.770000 user 1.750000 sys 0.020000 (best of 6) $ hg perfrevlogchunks -m ! chunk ! wall 2.587262 comb 2.580000 user 2.550000 sys 0.030000 (best of 4) ! wall 2.616330 comb 2.610000 user 2.560000 sys 0.050000 (best of 4) ! chunk batch ! wall 2.427092 comb 2.420000 user 2.400000 sys 0.020000 (best of 5) ! wall 2.462061 comb 2.460000 user 2.400000 sys 0.060000 (best of 4) Changelog chunk reading is slightly faster but manifest reading is slower. What gives? On this repo, 99.85% of changelog entries are zlib compressed (the 'x' header). On the manifest, 67.5% are zlib and 32.4% are '\0'. This patch swapped the test order of 'x' and '\0' so now 'x' is tested first. This makes changelogs faster since they almost always hit the first branch. This makes a significant percentage of manifest '\0' chunks slower because that code path now performs an extra test. Yes, I too can't believe we're able to measure the impact of an if..elif with simple string compares. I reckon this code would benefit from being written in C...

hgweb: build the "entries" list directly in filelog command There's no apparent reason to have this "entries" generator function that builds a list and then yields its elements in reverse order and which is only called to build the "entries" list. So just build the list directly, in reverse order. Adjust "parity" generator's offset to keep rendering the same.

convert: remove "replacecommitter" action As pointed out by Yuya, this action doesn't add much (any?) value.

ui: check EOF of getpass() response read from command-server channel readline() returns '' only when EOF is encountered, in which case, Python's getpass() raises EOFError. We should do the same to abort the session as "response expected." This bug was reported to https://bitbucket.org/tortoisehg/thg/issues/4659/

convert: config option to control Git committer actions When converting a Git repository to Mercurial at Mozilla, I encountered a scenario where I didn't want `hg convert` to automatically add the "committer: <committer>" line to commit messages. While I can hack around this by rewriting the Git commit before it is fed into `hg convert`, I figured it would be a useful knob to control. This patch introduces a config option that allows lots of control over the committer value. I initially implemented this as a single boolean flag to control whether to save the committer message. But then there was feedback that it would be useful to save the committer in extra data. While this patch doesn't implement support for saving in extra data, it does add a mechanism for extending which actions to take on the committer field. We should be able to easily add actions to save in extra data. Some of the implemented features weren't asked for. But I figured they could be useful. If nothing else they demonstrate the extensibility of this mechanism.

help: make "mergetool" an alias for "merge-tools" I've probably typed `hg help mergetool` dozens of times. I'm tired of it not working.

templatekw: force noprefix=False to insure diffstat consistency (issue4755) The result of diffstatdata should not depend on having noprefix set or not, as was reported in issue 4755. Forcing noprefix to false on call makes sure the parser receives the diff in the correct format and returns the proper result. Another way to fix this would have been to change the regular expressions in path.diffstatdata(), but that would have introduced many unecessary special cases.

check-code: reject module-level @cachefunc Module-level @cachefunc usage is risky because it can easily create a memory "leak". Let's reject it completely for now. If a valid usage comes up in the future, we can always improve the check or reconsider.

similar: remove caching from the module level To prevent Bad Things™ from happening, let's rework the logic to not use util.cachefunc.

patch: add label for coloring the similarity extended header Just like the summary says, this will colorize the: similarity index 88% line in the diff output.

patch: use opt.showsimilarity to calculate and show the similarity Tests have been added.

patch: add similarity config knob in experimental section This config knob will control whether or not to show the similarity calculation in the diff output: diff --git a/README.md b/foo.md similarity index 88% rename from README.md rename to foo.md --- a/README.md +++ b/foo.md

similar: move score function to module level Future patches will use this to report the similarity of a rename / copy in the patch output.

revset: abuse x:y syntax to specify line range of followlines() This slightly complicates the parsing (see the previous patch), but the overall result seems not bad. I keep x:, :y and : for future extension.

revset: do not transform range* operators in parsed tree This allows us to handle x:y range as a general range object. A primary user of it is followlines().

revset: add default value to getinteger() helper This seems handy.

revset: factor out getinteger() helper We have 4 revset functions that take integer arguments, and they handle their arguments in slightly different ways. This patch unifies them: - getstring() in place of getsymbol(), which is more consistent with the handling of integer revisions (both 1 and '1' are valid) - say "expects" instead of "requires" for type errors We don't need to catch TypeError since getstring() must return a string.

revset: rename rev argument of followlines() to startrev The rev argument has the same meaning as startrev of follow(), and I think startrev is more informative. followlines() is new function, we can make BC now.

help: use :hg: role and canonical name to point to revset string patterns Follows up 5dd67f0993ce. Now revisions.txt and revsets.txt has been merged, so use revisions.* as a pointer.

util: compression APIs to support revlog decompression Previously, compression engines had APIs for performing revlog compression but no mechanism to perform revlog decompression. This patch changes that. Revlog decompression is slightly more complicated than compression because in the compression case there is (currently) only a single engine that can be used at a time. However for decompression, a revlog could contain chunks from multiple compression engines. This means decompression needs to map to multiple engines and decompressors. This functionality is outside the scope of this patch. But it drives the decision for engines to declare a byte header sequence that identifies revlog data as belonging to an engine and an API for obtaining an engine from a revlog header.

crecord: add an experimental option for space key to move cursor down I really want to have an option of toggling a selection on a line and also moving cursor down as a single keystroke. It also kinda makes sense for space key to do this, because some other curses UIs in the wild do this (e.g. various file managers, htop). So I got an idea to make a config option that defaults to False for compatibility, but allows making crecord UI a lot more useful for people with big hunks. We add this an experimental option to experiment with this behavior.

perf: support multiple compression engines in perfrevlogchunks Now that the revlog has a reference to a compressor, it is possible to swap in other compression engines. So, teach `hg perfrevlogchunks` to do that. The default behavior of `hg perfrevlogchunks` is now to measure the compression performance of all compression engines implementing the revlog compressor API. This effectively adds the no-op "none" compressor and zstd (when available) into the default set. While we can't yet plug alternate compressors into revlogs, this command gives us a preview of the performance. On the mozilla-unified repository: $ hg perfrevlogchunks -c ! compress w/ none ! wall 0.115159 comb 0.110000 user 0.110000 sys 0.000000 (best of 86) ! compress w/ zlib ! wall 5.681406 comb 5.680000 user 5.680000 sys 0.000000 (best of 3) ! compress w/ zstd ! wall 2.624781 comb 2.620000 user 2.620000 sys 0.000000 (best of 4) $ hg perfrevlogchunks -m ! compress w/ none ! wall 0.124486 comb 0.120000 user 0.120000 sys 0.000000 (best of 79) ! compress w/ zlib ! wall 10.144701 comb 10.150000 user 10.150000 sys 0.000000 (best of 3) ! compress w/ zstd ! wall 4.383118 comb 4.390000 user 4.390000 sys 0.000000 (best of 3) Those numbers for zstd look promising. But they aren't the full story. For that, we'll need to look at decompression times and storage sizes. Stay tuned...

revlog: use compression engine API for compression This commit swaps in the just-added revlog compressor API into the revlog class. Instead of implementing zlib compression inline in compress(), we now store a cached-on-first-use revlog compressor on each revlog instance and invoke its "compress()" method. As part of this, revlog.compress() has been refactored a bit to use a cleaner code flow and modern formatting (e.g. avoiding parenthesis around returned tuples). On a mozilla-unified repo, here are the "compress" times for a few commands: $ hg perfrevlogchunks -c ! wall 5.772450 comb 5.780000 user 5.780000 sys 0.000000 (best of 3) ! wall 5.795158 comb 5.790000 user 5.790000 sys 0.000000 (best of 3) $ hg perfrevlogchunks -m ! wall 9.975789 comb 9.970000 user 9.970000 sys 0.000000 (best of 3) ! wall 10.019505 comb 10.010000 user 10.010000 sys 0.000000 (best of 3) Compression times did seem to slow down just a little. There are 360,210 changelog revisions and 359,342 manifest revisions. For the changelog, mean time to compress a revision increased from ~16.025us to ~16.088us. That's basically a function call or an attribute lookup. I suppose this is the price you pay for abstraction. It's so low that I'm not concerned.

util: compression APIs to support revlog compression As part of "zstd all of the things," we need to teach revlogs to use non-zlib compression formats. Because we're routing all compression via the "compression manager" and "compression engine" APIs, we need to introduction functionality there for performing revlog operations. Ideally, revlog compression and decompression operations would be implemented in terms of simple "compress" and "decompress" primitives. However, there are a few considerations that make us want to have a specialized primitive for handling revlogs: 1) Performance. Revlogs tend to do compression and especially decompression operations in batches. Any overhead for e.g. instantiating a "context" for performing an operation can be noticed. For this reason, our "revlog compressor" primitive is reusable. For zstd, we reuse the same compression "context" for multiple operations. I've measured this to have a performance impact versus constructing new contexts for each operation. 2) Specialization. By having a primitive dedicated to revlog use, we can make revlog-specific choices and leave the door open for more functionality in the future. For example, the zstd revlog compressor may one day make use of dictionary compression. A future patch will introduce a decompress() on the compressor object. The code for the zlib compressor is basically copied from revlog.compress(). Although it doesn't handle the empty input case, the null first byte case, and the 'u' prefix case. These cases will continue to be handled in revlog.py once that code is ported to use this API.

revlog: move decompress() from module to revlog class (API) Upcoming patches will convert revlogs to use the compression engine APIs to perform all things compression. The yet-to-be-introduced APIs support a persistent "compressor" object so the same object can be reused for multiple compression operations, leading to better performance. In addition, compression engines like zstd may wish to tweak compression engine state based on the revlog (e.g. per-revlog compression dictionaries). A global and shared decompress() function will shortly no longer make much sense. So, we move decompress() to be a method of the revlog class. It joins compress() there. On the mozilla-unified repo, we can measure the impact of this change on reading performance: $ hg perfrevlogchunks -c ! chunk ! wall 1.932573 comb 1.930000 user 1.900000 sys 0.030000 (best of 6) ! wall 1.955183 comb 1.960000 user 1.930000 sys 0.030000 (best of 6) ! chunk batch ! wall 1.787879 comb 1.780000 user 1.770000 sys 0.010000 (best of 6 ! wall 1.774444 comb 1.770000 user 1.750000 sys 0.020000 (best of 6) "chunk" appeared to become slower but "chunk batch" got faster. Upon further examination by running both sets multiple times, the numbers appear to converge across all runs. This tells me that there is no perceived performance impact to this refactor.

revlog: make compressed size comparisons consistent revlog.compress() compares the compressed size to the input size and throws away the compressed data if it is larger than the input. This is the correct thing to do, as storing compressed data that is larger than the input takes up more storage space and makes reading slower. However, the comparison was implemented inconsistently. For the streaming compression mode, we threw away the result if it was greater than or equal to the input size. But for the one-shot compression, we threw away the compression only if it was greater than the input size! This patch changes the comparison for the simple case so it is consistent with the streaming case. As a few tests demonstrate, this adds 1 byte to some revlog entries. This is because of an added 'u' header on the chunk. It seems somewhat wrong to increase the revlog size here. However, IMO the cost of 1 byte in storage is insignificant compared to the performance gains of avoiding decompression. This patch should invite questions around the heuristic for throwing away compressed data. For example, I'd argue we should be more liberal about rejecting compressed data, additionally doing so where the number of bytes saved fails to reach a threshold. But we can have this discussion another time.

similar: rename local variable to not collide with previous Future patches will move the score function to the module level, so let's not shadow that.

patch: add label for coloring the index extended header Just like the summary says, this will colorize the: index 3d3ba4b65e11..57274a0f46b2 100644 line in the diff output.

patch: add index line for diff output This helps highlighting in third-party diff coloring (which assumes git output) and maintains pedantic correctness with diff --git. Tests will be added at the end of the series.

patch: add config knob for displaying the index header This config knob can take an integer between 0 and 40 or a keyword ('none', 'short', 'full') to control the length of hash to output. It will display diffs with the git index header as such, diff --git a/mercurial/mdiff.py b/mercurial/mdiff.py index 112edf7..d6b52c5 100644 We'll put this in the experimental section for now.

bisect: refer directly to bisect() revset predicate in help We have specific syntax for displaying the help text for a particular revset predicate, so let's refer directly to the bisect() revset in the verbose bisect help. It seems likely that the user doesn't care about other revsets at that point, so they will probably not miss the text about the other revset predicates.

tests: use "hg help revisions.<predicate>" instead of grepping We have specific syntax for displaying the help text for a particular revset predicate, so use that instead of grepping through the full output.

help: remove now-redundant pointer to revsets help "hg help revisions" and "hg help revsets" now point to the same text, so drop the revsets reference.

help: eliminate duplicate text for revset string patterns There's no reason to duplicate this so many times, and it's likely an instance will be missed if support for a new pattern is added and documented. The stringmatcher is mostly used by revsets, though it is also used for the 'tag' related templates, and namespace filtering in the journal extension. So maybe there's a better place to document it. `hg help patterns` seems inappropriate, because that is all file pattern matching. While here, indicate how to perform case insensitive regex searches.

revset: add regular expression support to 'desc' This is a case insensitive predicate like 'author', so it conforms to the existing behavior of performing a case insensitive regex.

revset: stop lowercasing the regex pattern for 'author' It was probably unintentional for regex, as the meaning of some sequences like \S and \s is actually inverted by changing the case. For backward compatibility however, the matching is forced to case insensitive.

repair: clean up stale lock file from store backup Since we did a directory rename on the stores, the source repository's lock path now references the dest repository's lock path and the dest repository's lock path now references a non-existent filename. So releasing the lock on the source will unlock the dest and releasing the lock on the dest will no-op because it fails due to file not found. So we clean up the dest's lock manually.

repair: copy non-revlog store files during upgrade The store contains more than just revlogs. This patch teaches the upgrade code to copy regular files as well. As the test changes demonstrate, the phaseroots file is now copied.

repair: migrate revlogs during upgrade Our next step for in-place upgrade is to migrate store data. Revlogs are the biggest source of data within the store and a store is useless without them, so we implement their migration first. Our strategy for migrating revlogs is to walk the store and call `revlog.clone()` on each revlog. There are some minor complications. Because revlogs have different storage options (e.g. changelog has generaldelta and delta chains disabled), we need to obtain the correct class of revlog so inserted data is encoded properly for its type. Various attempts at implementing progress indicators that didn't lead to frustration from false "it's almost done" indicators were made. I initially used a single progress bar based on number of revlogs. However, this quickly churned through all filelogs, got to 99% then effectively froze at 99.99% when it got to the manifest. So I converted the progress bar to total revision count. This was a little bit better. But the manifest was still significantly slower than filelogs and it took forever to process the last few percent. I then tried both revision/chunk bytes and raw bytes as the denominator. This had the opposite effect: because so much data is in manifests, it would churn through filelogs without showing much progress. When it got to manifests, it would fill in 90+% of the progress bar. I finally gave up having a unified progress bar and instead implemented 3 progress bars: 1 for filelog revisions, 1 for manifest revisions, and 1 for changelog revisions. I added extra messages indicating the total number of revisions of each so users know there are more progress bars coming. I also added extra messages before and after each stage to give extra details about what is happening. Strictly speaking, this isn't necessary. But the numbers are impressive. For example, when converting a non-generaldelta mozilla-central repository, the messages you see are: migrating 2475593 total revisions (1833043 in filelogs, 321156 in manifests, 321394 in changelog) migrating 1.67 GB in store; 2508 GB tracked data migrating 267868 filelogs containing 1833043 revisions (1.09 GB in store; 57.3 GB tracked data) finished migrating 1833043 filelog revisions across 267868 filelogs; change in size: -415776 bytes migrating 1 manifests containing 321156 revisions (518 MB in store; 2451 GB tracked data) That "2508 GB" figure really blew me away. I had no clue that the raw tracked data in mozilla-central was that large. Granted, 2451 GB is in the manifest and "only" 57.3 GB is in filelogs. But still. It's worth noting that gratuitous loading of source revlogs in order to display numbers and progress bars does serve a purpose: it ensures we can open all source revlogs. We don't want to spend several minutes copying revlogs only to encounter a permissions error or similar later. As part of this commit, we also add swapping of the store directory to the upgrade function. After revlogs are converted, we move the old store into the backup directory then move the temporary repo's store into the old store's location. On well-behaved systems, this should be 2 atomic operations and the window of inconsistency show be very narrow. There are still a few improvements to be made to store copying and upgrading. But this commit gets the bulk of the work out of the way.

revlog: add clone method Upcoming patches will introduce functionality for in-place repository/store "upgrades." Copying the contents of a revlog feels sufficiently low-level to warrant being in the revlog class. So this commit implements that functionality. Because full delta recomputation can be *very* expensive (we're talking several hours on the Firefox repository), we support multiple modes of execution with regards to delta (re)use. This will allow repository upgrades to choose the "level" of processing/optimization they wish to perform when converting revlogs. It's not obvious from this commit, but "addrevisioncb" will be used for progress reporting.

repair: begin implementation of in-place upgrading Now that all the upgrade planning work is in place, we can start doing the real work: actually upgrading a repository. The main goal of this commit is to get the "framework" for running in-place upgrade actions in place. Rather than get too clever and low-level with regards to in-place upgrades, our strategy is to create a new, temporary repository, copy data to it, then replace the old data with the new. This allows us to reuse a lot of code in localrepo.py around store interaction, which will eventually consume the bulk of the upgrade code. But we have to start small. This patch implements adding new repository requirements. But it still sets up a temporary repository and locks it and the source repo before performing the requirements file swap. This means all the plumbing is in place to implement store copying in subsequent commits.

repair: determine what upgrade will do This commit introduces code for determining what actions/improvements an upgrade should perform. The "upgradefindimprovements" function introduces a mechanism to return a list of improvements that can be made to a repository. Each improvement is effectively an action that an upgrade will perform. Associated with each of these improvements is metadata that will be used to inform users what's wrong and what an upgrade will do. Each "improvement" is categorized as a "deficiency" or an "optimization." TBH, I'm not thrilled about the terminology and am receptive to constructive bikeshedding. The main difference between a "deficiency" and an "optimization" is a deficiency is always corrected (if it deviates from the current config) and an "optimization" is an optional action that goes above and beyond to improve the state of the repository (usually by requiring more CPU during upgrade). Our initial set of improvements identifies missing repository requirements, a single, easily correctable problem with changelog storage, and a set of "optimizations" related to delta recalculation. The main "upgraderepo" function has been expanded to handle improvements. It queries for the list of improvements and determines which of them will run based on the current repository state and user I went through numerous iterations of the output format before settling on a ReST-inspired definition list format. (I used bulleted lists in the first submission of this commit and could not get it to format just right.) Even with the various iterations, I'm still not super thrilled with the format. But, this is a debug* command, so that should mean we can refine the output without BC concerns.

repair: implement requirements checking for upgrades This commit introduces functionality for upgrading a repository in place. The first part that's implemented is testing for upgrade "compatibility." This is done by examining repository requirements. There are 5 functions returning sets of requirements that control upgrading. Why so many functions? Mainly to support extensions. Functions are easier to monkeypatch than module variables. Astute readers will see that we don't support "manifestv2" and "treemanifest" requirements in the upgrade mechanism. I don't have a great answer for why other than this is a complex set of patches and I don't want to deal with the complexity of these experimental features just yet. We can teach the upgrade mechanism about them later, once the basic upgrade mechanism is in place. This commit also introduces the "upgraderepo" function. This will be our main routine for performing an in-place upgrade. Currently, it just implements requirements checking. The structure of some code in this function may look a bit weird (e.g. the inline function that is only called once). But this will make sense after future commits.

debugcommands: stub for debugupgraderepo command Currently, if Mercurial introduces a new repository/store feature or changes behavior of an existing feature, users must perform an `hg clone` to create a new repository with hopefully the correct/optimal settings. Unfortunately, even `hg clone` may not give the correct results. For example, if you do a local `hg clone`, you may get hardlinks to revlog files that inherit the old state. If you `hg clone` from a remote or `hg clone --pull`, changegroup application may bypass some optimization, such as converting to generaldelta. Optimizing a repository is harder than it seems and requires more than a simple `hg` command invocation. This commit starts the process of changing that. We introduce `hg debugupgraderepo`, a command that performs an in-place upgrade of a repository to use new, optimal features. The command is just a stub right now. Features will be added in subsequent commits. This commit does foreshadow some of the behavior of the new command, notably that it doesn't do anything by default and that it takes arguments that influence what actions it performs. These will be explained more in subsequent commits.

util: teach stringmatcher to handle forced case insensitive matches The 'author' and 'desc' revsets are documented to be case insensitive. Unfortunately, this was implemented in 'author' by forcing the input to lowercase, including for regex like '\B'. (This actually inverts the meaning of the sequence.) For backward compatibility, we will keep that a case insensitive regex, but by using matcher options instead of brute force. This doesn't preclude future hypothetical 'icase-literal:' style prefixes that can be provided by the user. Such user specified cases can probably be handled up front by stripping 'icase-', setting the variable, and letting it drop through the existing code.

revset: point to 'grep' in the 'keyword' help for regex searches The help for 'grep' already points to 'keyword'.

help: explain that revsets can be used where 1 or 2 revs are wanted We did not seem to document that one can do things like "hg up :@" where the last revision of the revset ":@".

help: explain what the term "revset" means We refer to revsets in a few places (e.g. in "hg help config"), but we never explained what they are. Until now.

help: merge revsets.txt into revisions.txt Selecting single and multiple revisions is closely related, so let's put it in one place, so users can easily find it. We actually did not even point to "hg help revsets" from "hg help revisions", but now that they're on a single page, that won't be necessary.

tests: use `hg help dates` instead of `hg help revs` in test The revisions help is already long and will get longer, so switch to another short and stable topic.

help: use a single paragraph to describe full and abbreviated nodeids The texts describing 40-digit strings and the abbreviated form are closely related, so make it a single paragraph.

hgweb: support Content Security Policy Content-Security-Policy (CSP) is a web security feature that allows servers to declare what loaded content is allowed to do. For example, a policy can prevent loading of images, JavaScript, CSS, etc unless the source of that content is whitelisted (by hostname, URI scheme, hashes of content, etc). It's a nifty security feature that provides extra mitigation against some attacks, notably XSS. Mitigation against these attacks is important for Mercurial because hgweb renders repository data, which is commonly untrusted. While we make attempts to escape things, etc, there's the possibility that malicious data could be injected into the site content. If this happens today, the full power of the web browser is available to that malicious content. A restrictive CSP policy (defined by the server operator and sent in an HTTP header which is outside the control of malicious content), could restrict browser capabilities and mitigate security problems posed by malicious data. CSP works by emitting an HTTP header declaring the policy that browsers should apply. Ideally, this header would be emitted by a layer above Mercurial (likely the HTTP server doing the WSGI "proxying"). This works for some CSP policies, but not all. For example, policies to allow inline JavaScript may require setting a "nonce" attribute on <script>. This attribute value must be unique and non-guessable. And, the value must be present in the HTTP header and the HTML body. This means that coordinating the value between Mercurial and another HTTP server could be difficult: it is much easier to generate and emit the nonce in a central location. This commit introduces support for emitting a Content-Security-Policy header from hgweb. A config option defines the header value. If present, the header is emitted. A special "%nonce%" syntax in the value triggers generation of a nonce and inclusion in <script> elements in templates. The inclusion of a nonce does not occur unless "%nonce%" is present. This makes this commit completely backwards compatible and the feature opt-in. The nonce is a type 4 UUID, which is the flavor that is randomly generated. It has 122 random bits, which should be plenty to satisfy the guarantees of a nonce.

hgweb: call process_dates() via DOM event listener All the hgweb templates include mercurial.js in their header. All the hgweb templates have the same <script> boilerplate to run process_dates(). This patch factors that function call into mercurial.js as part of a DOMContentLoaded event listener.

protocol: send application/mercurial-0.2 responses to capable clients With this commit, the HTTP transport now parses the X-HgProto-<N> header to determine what media type and compression engine to use for responses. So far, we only compress responses that are already being compressed with zlib today (stream response types to specific commands). We can expand things to cover additional response types later. The practical side-effect of this commit is that non-zlib compression engines will be used if both ends support them. This means if both ends have zstd support, zstd - not zlib - will be used to compress data! When cloning the mozilla-unified repository between a local HTTP server and client, the benefits of non-zlib compression are quite noticeable: engine server CPU (s) client CPU (s) bundle size zlib (l=6) 174.1 283.2 1,148,547,026 zstd (l=1) 99.2 267.3 1,127,513,841 zstd (l=3) 103.1 266.9 1,018,861,363 zstd (l=7) 128.3 269.7 919,190,278 zstd (l=10) 162.0 - 894,547,179 none 95.3 277.2 4,097,566,064 The default zstd compression level is 3. So if you deploy zstd capable Mercurial to your clients and servers and CPU time on your server is dominated by "getbundle" requests (clients cloning and pulling) - and my experience at Mozilla tells me this is often the case - this commit could drastically reduce your server-side CPU usage *and* save on bandwidth costs! Another benefit of this change is that server operators can install *any* compression engine. While it isn't enabled by default, the "none" compression engine can now be used to disable wire protocol compression completely. Previously, commands like "getbundle" always zlib compressed output, adding considerable overhead to generating responses. If you are on a high speed network and your server is under high load, it might be advantageous to trade bandwidth for CPU. Although, zstd at level 1 doesn't use that much CPU, so I'm not convinced that disabling compression wholesale is worthwhile. And, my data seems to indicate a slow down on the client without compression. I suspect this is due to a lack of buffering resulting in an increase in socket read() calls and/or the fact we're transferring an extra 3 GB of data (parsing HTTP chunked transfer and processing extra TCP packets can add up). This is definitely worth investigating and optimizing. But since the "none" compressor isn't enabled by default, I'm inclined to punt on this issue. This commit introduces tons of tests. Some of these should arguably have been implemented on previous commits. But it was difficult to test without the server functionality in place.

httppeer: advertise and support application/mercurial-0.2 Now that servers expose a capability indicating they support application/mercurial-0.2 and compression, clients can key off this to say they support responses that are compressed with various compression formats. After this commit, the HTTP wire protocol client now sends an "X-HgProto-<N>" request header indicating its support for "application/mercurial-0.2" media type and various compression formats. This commit also implements support for handling "application/mercurial-0.2" responses. It simply reads the header compression engine identifier then routes the remainder of the response to the appropriate decompressor. There were some test changes, but only to logging. That points to an obvious gap in our test coverage. This will be addressed in a subsequent commit once server support is in place (it is hard to test without server support).

wireproto: advertise supported media types and compression formats This commit introduces support for advertising a server's support for media types and compression formats in accordance with the spec defined in internals.wireproto. The bulk of the new code is a helper function in wireproto.py to obtain a prioritized list of compression engines available to the wire protocol. While not utilized yet, we implement support for obtaining the list of compression engines advertised by the client. The upcoming HTTP protocol enhancements are a bit lower-level than existing tests (most existing tests are command centric). So, this commit establishes a new test file that will be appropriate for holding tests around the functionality of the HTTP protocol itself. Rounding out this change, `hg debuginstall` now prints compression engines available to the server.

util: declare wire protocol support of compression engines This patch implements a new compression engine API allowing compression engines to declare support for the wire protocol. Support is declared by returning a compression format string identifier that will be added to payloads to signal the compression type of data that follows and default integer priorities of the engine. Accessor methods have been added to the compression engine manager class to facilitate use. Note that the "none" and "bz2" engines declare wire protocol support but aren't enabled by default due to their priorities being 0. It is essentially free from a coding perspective to support these compression formats, so we do it in case anyone may derive use from it.

internals: document compression negotiation As part of adding zstd support to all of the things, we'll need to teach the wire protocol to support non-zlib compression formats. This commit documents how we'll implement that. To understand how we arrived at this proposal, let's look at how things are done today. The wire protocol today doesn't have a unified format. Instead, there is a limited facility for differentiating replies as successful or not. And, each command essentially defines its own response format. A significant deficiency in the current protocol is the lack of payload framing over the SSH transport. In the HTTP transport, chunked transfer is used and the end of an HTTP response body (and the end of a Mercurial command response) can be identified by a 0 length chunk. This is how HTTP chunked transfer works. But in the SSH transport, there is no such framing, at least for certain responses (notably the response to "getbundle" requests). Clients can't simply read until end of stream because the socket is persistent and reused for multiple requests. Clients need to know when they've encountered the end of a request but there is nothing simple for them to key off of to detect this. So what happens is the client must decode the payload (as opposed to being dumb and forwarding frames/packets). This means the payload itself needs to support identifying end of stream. In some cases (bundle2), it also means the payload can encode "error" or "interrupt" events telling the client to e.g. abort processing. The lack of framing on the SSH transport and the transfer of its responsibilities to e.g. bundle2 is a massive layering violation and a wart on the protocol architecture. It needs to be fixed someday by inventing a proper framing protocol. So about compression. The client transport abstractions have a "_callcompressable()" API. This API is called to invoke a remote command that will send a compressible response. The response is essentially a "streaming" response (no framing data at the Mercurial layer) that is fed into a decompressor. On the HTTP transport, the decompressor is zlib and only zlib. There is currently no mechanism for the client to specify an alternate compression format. And, clients don't advertise what compression formats they support or ask the server to send a specific compression format. Instead, it is assumed that non-error responses to "compressible" commands are zlib compressed. On the SSH transport, there is no compression at the Mercurial protocol layer. Instead, compression must be handled by SSH itself (e.g. `ssh -C`) or within the payload data (e.g. bundle compression). For the HTTP transport, adding new compression formats is pretty straightforward. Once you know what decompressor to use, you can stream data into the decompressor until you reach a 0 size HTTP chunk, at which point you are at end of stream. So our wire protocol changes for the HTTP transport are pretty straightforward: the client and server advertise what compression formats they support and an appropriate compression format is chosen. We introduce a new HTTP media type to hold compressed payloads. The header of the payload defines the compression format being used. Whoever is on the receiving end can sniff the first few bytes route to an appropriate decompressor. Support for multiple compression formats is advertised on both server and client. The server advertises a "compression" capability saying which compression formats it supports and in what order they are preferred. Clients advertise their support for multiple compression formats and media types via the introduced "X-HgProto" request header. Strictly speaking, servers don't need to advertise which compression formats they support. But doing so allows clients to fail fast if they don't support any of the formats the server does. This is useful in situations like sending bundles, where the client may have to perform expensive computation before sending data to the server. Rather than simply advertise a list of supported compression formats, we introduce an additional "httpmediatype" server capability advertising which media types the server supports. This means servers are explicit about what formats they exchange. IMO, this is superior to inferring support from other capabilities (like "compression"). By advertising compression support on each request in the "X-HgProto" header and media type and direction at the server level, we are able to gradually transition existing commands/responses to the new media type and possibly compression. Contrast with the old world, where we only supported a single media type and the use of compression was built-in to the semantics of the command on both client and server. In the new world, if "application/mercurial-0.2" is supported, compression is supported. It's that simple. It's worth noting that we explicitly don't use "Accept," "Accept-Encoding," "Content-Encoding," or "Transfer-Encoding" for content negotiation and compression. People knowledgeable of the HTTP specifications will say that we should use these because that's what they are designed to be used for. They have a point and I sympathize with the argument. Earlier versions of this commit even defined supported media types in the "Accept" header. However, my years of experience rolling out services leveraging HTTP has taught me to not trust the HTTP layer, especially if you are going outside the normal spec (such as using a custom "Content-Encoding" value to represent zstd streams). I've seen load balancers, proxies, and other network devices do very bad and unexpected things to HTTP messages (like insisting zlib compressed content is decoded and then re-encoded at a different compression level or even stripping compression completely). I've found that the best way to avoid surprises when writing protocols on top of HTTP is to use HTTP as a dumb transport as much as possible to minimize the chances that an "intelligent" agent between endpoints will muck with your data. While the widespread use of TLS is mitigating many intermediate network agents interfering with HTTP, there are still problems at the edges, with e.g. the origin HTTP server needing to convert HTTP to and from WSGI and buggy or feature-lacking HTTP client implementations. I've found the best way to avoid these problems is to avoid using headers like "Content-Encoding" and to bake as much logic as possible into media types and HTTP message bodies. The protocol changes in this commit do rely on a custom HTTP request header and the "Content-Type" headers. But we used them before, so we shouldn't be increasing our exposure to "bad" HTTP agents. For the SSH transport, we can't easily implement content negotiation to determine compression formats because the SSH transport has no content negotiation capabilities today. And without a framing protocol, we don't know how much data to feed into a decompressor. So in order to implement compression support on the SSH transport, we'd need to invent a mechanism to represent content types and an outer framing protocol to stream data robustly. While I'm fully capable of doing that, it is a lot of work and not something that should be undertaken lightly. My opinion is that if we're going to change the SSH transport protocol, we should take a long hard look at implementing a grand unified protocol that attempts to address all the deficiencies with the existing protocol. While I want this to happen, that would be massive scope bloat standing in the way of zstd support. So, I've decided to take the easy solution: the SSH transport will not gain support for multiple compression formats. Keep in mind it doesn't support *any* compression today. So essentially nothing is changing on the SSH front.

httppeer: extract code for HTTP header spanning A second consumer of HTTP header spanning will soon be introduced. Factor out the code to do this so it can be reused.

commands: config option to control bundle compression level Currently, bundle compression uses the default compression level for the active compression engine. The default compression level is tuned as a compromise between speed and size. Some scenarios may call for a different compression level. For example, with clone bundles, bundles are generated once and used several times. Since the cost to generate is paid infrequently, server operators may wish to trade extra CPU time for better compression ratios. This patch introduces an experimental and undocumented config option to control the bundle compression level. As the inline comment says, this approach is a bit hacky. I'd prefer for the compression level to be encoded in the bundle spec. e.g. "zstd-v2;complevel=15." However, given that the 4.1 freeze is imminent, I'm not comfortable implementing this user-facing change without much time to test and consider the implications. So, we're going with the quick and dirty solution for now. Having this option in the 4.1 release will enable Mozilla to easily produce and test zlib and zstd bundles with non-default compression levels in production. This will help drive future development of the feature and zstd integration with Mercurial.

bundle2: allow compression options to be passed to compressor Compression engines allow options to be passed to them to control behavior. This patch exposes an argument to bundle2.writebundle() that passes options to the compression engine when writing compressed bundles. The argument is honored for both bundle1 and bundle2, the latter requiring a bit of plumbing to pass the value around.

chg: check snprintf result strictly This makes the program more robust when somebody changes hgclient's maxdatasize in the future.

rebase: provide detailed hint to abort message if working dir is not clean Detailed hint message is now provided when 'pull --rebase' operation detects unclean working dir, for example: abort: uncommitted changes (cannot pull with rebase: please commit or shelve your changes first) Added tests for uncommitted merge, and for subrepo support verifying that same hint is also passed to subrepo state check.

revset: parse variable-length arguments of followlines() by getargsdict()

parser: extend buildargsdict() to support variable-length positional args This can simplify the argument parsing of followlines(). Tests are added by the next patch.

parser: make buildargsdict() precompute position where keyword args start This prepares for adding *varargs support. See the next patch.

chg: change server's process title This patch uses the newly introduced "setprocname" interface to update the process title server-side, to make it easier to tell what a worker is actually doing. The new title is "chg[worker/$PID]", where PID is the process ID of the connected client. It can be directly observed using "ps -AF" under Linux, or "ps -A" under FreeBSD.

chgserver: add the setprocname interface This allows clients to change its process title freely.

hgweb: use archivespecs for links on repo index page too Moving archivespecs to the module level allows using it from other modules (such as hgwebdir_mod), and keeping a reference to it in requestcontext allows current code to just work.

hgweb: use util.sortdict for archivespecs Thus we allow dict-like indexing and "in" checks, and also preserve the order of archive types and can generate links in a certain order (so requestcontext.archives is no longer needed).

hgweb: test the order of archive links

revlog: REVIDX_EXTSTORED flag This flag will be used by the lfs extension to mark the revision data as stored externally.

revlog: flag processor Add the ability for revlog objects to process revision flags and apply registered transforms on read/write operations. This patch introduces: - the 'revlog._processflags()' method that looks at revision flags and applies flag processors registered on them. Due to the need to handle non-commutative operations, flag transforms are applied in stable order but the order in which the transforms are applied is reversed between read and write operations. - the 'addflagprocessor()' method allowing to register processors on flags. Flag processors are defined as a 3-tuple of (read, write, raw) functions to be applied depending on the operation being performed. - an update on 'revlog.addrevision()' behavior. The current flagprocessor design relies on extensions to wrap around 'addrevision()' to set flags on revision data, and on the flagprocessor to perform the actual transformation of its contents. In the lfs case, this means we need to process flags before we meet the 2GB size check, leading to performing some operations before it happens: - if flags are set on the revision data, we assume some extensions might be modifying the contents using the flag processor next, and we compute the node for the original revision data (still allowing extension to override the node by wrapping around 'addrevision()'). - we then invoke the flag processor to apply registered transforms (in lfs's case, drastically reducing the size of large blobs). - finally, we proceed with the 2GB size check. Note: In the case a cachedelta is passed to 'addrevision()' and we detect the flag processor modified the revision data, we chose to trust the flag processor and drop the cachedelta.

revlog: pass revlog flags to addrevision Adding the ability to passing flags to addrevision instead of simply passing default flags to _addrevision will allow extensions relying on flag transforms to wrap around addrevision() in order to update revlog flags. The first use case of this patch will be the lfs extension marking nodes as stored externally when the contents are larger than the defined threshold. One of the reasons leading to setting flags in addrevision() wrappers in the flag processor design is that it allows to detect files larger than the 2GB limit before the check is performed, which allows lfs to transform the contents into metadata.

revlog: add 'raw' argument to revision and _addrevision This patch introduces a new 'raw' argument (defaults to False) to revlog's revision() and _addrevision() methods. When the 'raw' argument is set to True, it indicates the revision data should be handled as raw data by the flagprocessor. Note: Given revlog.addgroup() calls are restricted to changegroup generation, we can always set raw to True when calling revlog._addrevision() from revlog.addgroup().

pager: do not special case chg Since chg has its own _runpager implementation, it's no longer necessary to special-case chg in the pager extension. This will effectively enable the new chg pager code path that runs inside runcommand.

chg: remove getpager support We have enough bits to switch to the new chg pager code path in runcommand. So just remove the legacy getpager support. This is a red-only patch, and will break chg's pager support temporarily.

chgserver: implement chgui._runpager This patch implements chgui._runpager in a relatively simple way. A more clean way is to move the core logic of "attachio" to "ui", which will be done later after chg runs uisetup per request.

chgserver: make S channel support pager request This patch adds the "pager" support for the S channel. The pager API allows running some subcommands, namely attachio, and waiting for the client to be properly synchronized.

chg: handle pager request client-side This patch implements the simple S-channel pager handling at chg client-side. Note: It does not deal with environ and cwd currently for simplicity, which will be fixed later.

chgserver: use util.shellenviron This avoids code duplication.

util: extract the logic calculating environment variables The method will be reused in chgserver. Move it out so it can be reused.

hgweb: generate archive links in order It would be nice for archive links to always be in a certain commonly used order, such as 'zip', 'bz', 'gzip2'. Repo index page (hgwebdir_mod) already shows archive links in this order, let's do the same in hgweb_mod. Sadly, archivespecs is a regular unordered dict, and collections.OrderedDict is new in 2.7. But requestcontext.archives is a tuple of archive types, so it can be used as an index to archivespecs.

hgweb: use archivespecs (dict) instead of archives (tuple) for "in" check

test-obsolete: stabilize output on platforms without 'serve' support The conditional was updating the repository, which wasn't reflected in subsequent logs on Windows, so the conditional is narrowed to just the serve commands. The serve operation generates log files, so those are deleted to keep the output of summary consistent.

tests: update globs for Windows The extra glob in test-command-template.t caused it to say no result was reported. It used to be (within the past year), that both this and the missing glob cases could be fixed simply by editing any output in the test, and re-running it in interactive mode. But that no longer works, and I had to diff *.t against *.t.err. I didn't dig into what changed.

help: merge the various operator sections of revsets, filesets and templates Having sections for specific operator types assumes the user already knows what type of operators are supported. By having a common heading, the user can simply lookup help for "(revsets|filesets|templates).operators".

help: apply the section headings from revsets to templates Unlike filesets, there are a few distinct headings that are not shared with revsets. But common names are used where possible.

help: apply the section headings from revsets to filesets This has the nice property of visually breaking up the wall of text. It also allows specific smaller sections to be called out. For example, `hg help filesets.predicates` now prints just the predicate section. At the moment, the revset headings are a superset of the fileset headings, so there is consistency in how example, predicate and operator help is called out. The reference to `hg help patterns` was moved to the overview section, so that it isn't stuck in the examples section.

chg: check type read from S channel The previous patch added the check server-side. This patch added it client-side.

chgserver: check type passed to S channel It currently only supports the "system" type. Add an explicit check.

chg: send type information via S channel (BC) Previously S channel is only used to send system commands. It will also be used to send pager commands. So add a type parameter. This breaks older chg clients. But chg and hg should always come from a single commit and be packed into a single package. Supporting running inconsistent versions of chg and hg seems to be unnecessarily complicated with little benefit. So just make the change and assume people won't use inconsistent chg with hg.

rebase: fail-fast the pull if working dir is not clean (BC) Refuse to run 'hg pull --rebase' if there are uncommitted changes: so that instead of going ahead with fetching changes and then suddenly aborting the rebase, we can warn user of uncommitted changes (or unclean repo state) right up front. In tests, we create a 'histedit' session to verify that also an unfinished state is detected and handled.

commit: fix unmodified message detection for the "--- >8 ----" magic We need the raw editortext to be compared with the templatetext.

commit: update test to actually modify template text We have a check for unmodified commit message (introduced by bec1a579ebc4), which should be enabled for the "--- >8 ---" magic but currently not.

pager: wrap ui._runpager As discussed at [1], ui._runpager will be the new low-level API accepting a pager command to actually run the pager. And ui.pager is the high-level API which reads config directly from self. This change is necessary for chgserver to override _runpager cleanly. [1]: www.mercurial-scm.org/pipermail/mercurial-devel/2016-December/091656.html

summary: use ui.label and join to write evolution troubles Follow-up on 7b526670f540 to avoid a convoluted loop.

log: drop unnecessary ui.note label from "trouble: " line Follow-up on f05ede08dcf7 and 6d0b1a69f98c.

revset: add a followlines(file, fromline, toline[, rev]) revset This revset returns the history of a range of lines (fromline, toline) of a file starting from `rev` or the current working directory. Added tests in test-annotate.t which already contains a reasonably complex repository.

context: add a `blockancestors(fctx, fromline, toline)` function This yields ancestors of `fctx` by only keeping changesets touching the file within specified linerange = (fromline, toline). Matching revisions are found by inspecting the result of `mdiff.allblocks()`, filtered by `mdiff.blocksinrange()`, to find out if there are blocks of type "!" within specified line range. If, at some iteration, an ancestor with an empty line range is encountered, the algorithm stops as it means that the considered block of lines actually has been introduced in the revision of this iteration. Otherwise, we finally yield the initial revision of the file as the block originates from it. When a merge changeset is encountered during ancestors lookup, we consider there's a diff in the current line range as long as there is a diff between the merge changeset and at least one of its parents (in the current line range).

mdiff: add a "blocksinrange" function to filter diff blocks by line range The function filters diff blocks as generated by mdiff.allblock function based on whether they are contained in a given line range based on the "b-side" of blocks.

run-tests: unset CHGDEBUG With CHGDEBUG, chg outputs much more stuff and the test could fail running with --chg. So unset the environment variable.

summary: add evolution "troubles" information to summary output Extend the "parent: " lines in summary with the list of evolution "troubles" in parentheses, when the parent is troubled.

summary: use the same labels as log command in "parent: " line Re-use the cmdutil._changesetlabels function introduced in 5289fd78017a to have consistent labels between the "changeset: " line in log command and the "parent: " line in summary.

templates: display evolution "troubles" in command line style

templatekw: add a "troubles" template keyword The "troubles" template keyword returns a list of evolution troubles. It is EXPERIMENTAL, as anything else related to changeset evolution. Test it in test-obsolete.t which has troubled changesets.

test: test "trouble: " line in log output with multiple troubles Follow-up on f05ede08dcf7.

cmdutil: add missing "i18n" comment about "trouble: " line Follow-up on f05ede08dcf7 per late review.

rebase: use repo.vfs.exists in 'hg summary' hook

hgweb: link to raw-file on annotation page (BC) Every other template has the "raw" link load "raw-file." However, fileannotate.tmpl's "raw" link loads "raw-annotate." This feels inconsistent and wrong. As far as I can tell, linking to the "raw annotate" view has occurred since 2006.

repair: combine two loops over changelog revisions This just saves a few lines.

repair: speed up stripping of many roots repair.strip() expects a set of root revisions to strip. It then builds the full set of descedants by walking the descandants of each. It is rare that more than a few roots get passed in, but if that happens, it will wastefully walk the changelog for each root. So let's just walk it once. I noticed this because the narrowhg extension was passing not only roots, but all the commits to strip. When there were tens of thousands of commits to strip, this resulted in quadratic behavior with that extension.

make: remove targets for building packages for ubuntu wily (end of life) Ubuntu 15.10 (Wily Werewolf) came out on October 22, 2015 and reached end of life on July 28, 2016 [1]. Users were encouraged to upgrade to 16.04 (Xenial). PPA doesn't allow new uploads targeting 15.10 anymore. [1]: https://wiki.ubuntu.com/Releases

config: add docs for ignoring all text below in the editor This is an example of how to use the new skip-from-there string for ignoring the diff in a commit message.

cmdutil: add special string that ignores rest of text Similar to git, we add a special string: HG: ------------------------ >8 ------------------------ that means anything below it is ignored in a commit message. This is helpful for integrating with third-party tools that display the

revset: drop TODO comment about sorting issue of fullreposet The bootstrapping issue was addressed at the parsing phase and we expect that fullreposet.__and__() fully complies to the smartset API, in which 'self & other' should return a result set in self's order. See also 90455e7bf543.

revset: document wdir() as an experimental function Let's resurrect the docstring since our help module can detect the EXPERIMENTAL tag and display it only if -v is specified. This patch updates the test added by 015c0d1087a3 since wdir() is now documented.

revset: categorize wdir() as very fast function The cost of wdir() should be identical to or cheaper than _intlist().

revset: make children() not look at p2 if null (issue5439) Unlike p1 = null, p2 = null denotes the revision has only one parent, which shouldn't be considered a child of the null revision. This was spotted while fixing the issue4682 and rediscovered as issue5439.

setup: pass named argument to setup_zstd The next release from upstream adds another named argument to this function. Specify arguments by name so there is no ambiguity about which argument is being passed.

merge with stable

templates-default: factor out definition of changeset labels This is redundant for normal and debug mode and prepares extension of this list that should effect both modes.

cmdutil: add support for evolution "troubles" display in changeset_printer Add a "trouble" line in changeset header along with a couple of labels on "log.changeset" line to indicate whether a changeset is troubled or not and which kind trouble occurs.

cmdutil: extract a _changesetlabels function out of changeset_printer._show() There is a common logic in changeset_printer and in the summary command for labelling a changeset. This prepares extension of changeset's labels with evolution "troubles" information that would show up in both log and summary outputs. Ultimately, both would use this function.

chg: add procutil.h This patch adds a formal header procutil.h for procutil.c, and changes Makefile to build procutil.c independently.

chg: let procutil maintain its own pagerpid Previously, chg.c maintains the pagerpid. Let's move it to procutil.c. Note: chg.c still have a pagerpid to decide whether to call attachio or not. In the future, attachio may be moved from hgc_open to hgc_runcommand, and hgc_runcommand handles both pager and attachio so we don't need to run attachio twice. And chg.c will be free of pagerpid.

chg: decouple hgclient from setuppager procutil should not depend on hgclient. This patch makes the pager handling part independent from hgclient.

chg: decouple hgclient from setupsignalhandler procutil should not depend on hgclient. This patch makes the signal handling part independent from hgclient.

chg: move signal and pager handling to a separate file In the future hgclient will deal with pager directly inside runcommand, so related signal handling stuff needs to be decoupled from chg.c. The signal handling and pager logic are coupled because we need to forward SIGPIPE when pager exits. So they are moved together, otherwise a global variable (pagerpid) is inevitable. This patch moves related functions from chg.c to procutil.c, which was marked as copied to maintain annotate history. The move is done without code modification for easy review, therefore `#include "procutil.c"` was introduced temporarily.

keepalive: rewrite readline() The old method was performing string concatenation, which is slower than collecting raw chunks in a list and joining at the end.

keepalive: remove limit argument from readline() It is unused and adds complexity.

keepalive: don't concatenate strings when reading chunked transfer Surprisingly, this didn't appear to speed up HTTP-based stream cloning on my machine. I suspect this has more to do with the fact we're using small HTTP chunks and string concatenation overhead isn't so bad. However, the reasons for this change are solid: we know string concatenation can be a performance sink.

exchange: use rich class for sorting clone bundle entries Python 3 removed the "cmp" argument from sorted(). Custom sorting in Python 3 must be implemented with the dunder comparison methods on types and/or with a "key" function. This patch converts our custom "cmp" function to a custom type. The implementation is very similar to functools.cmp_to_key(). However, cmp_to_key() doesn't exist in Python 2, so we can't use it. This was the only use of the "cmp" argument to sorted() in the code base.

Added signature for changeset e69874dc1f4e

Added tag 4.0.2 for changeset e69874dc1f4e

i18n-ja: synchronized with 5f33116cd787

chg: respect XDG_RUNTIME_DIR $XDG_RUNTIME_DIR [1] is a better place for user daemons. Let's use it and fallback to $TMPDIR. After this patch, chg will try socket paths in the following order: 1. $CHGSOCKNAME 2. $XDG_RUNTIME_DIR/chg/server 3. ${TMPDIR:-tmp}/chg$UID/server [1]: https://standards.freedesktop.org/basedir-spec/basedir-spec-latest.html

chg: make "get default sockdir" a separate method The logic to get a default socket directory will become longer in the next patch. So let's move it out.

chg: handle connect failure before errno gets overridden This patch moves the error handling logic up so that errno after connect won't be overridden.

py3: have a bytes version of shlex.split() shlex.split() only accepts unicodes on Python 3. After this patch we will be using pycompat.shlexsplit(). This patch also replaces existing occurences of shlex.split with pycompat.shlexsplit.

chg: support long socket path This patch replaces UNIX_PATH_MAX (108) with PATH_MAX (4096) so we can have long unix path.

chg: remove sockdirfd See the previous patch for the reason.

chg: let hgc_open support long path "sizeof(sun_path)" is too small. Use the chdir trick to support long socket path, like "mercurial.util.bindunixsocket". It's useful for cases where TMPDIR is long. Modern OS X rewrites TMPDIR to a long value. And we probably want to use XDG_RUNTIME_DIR [2] for Linux. The approach is a bit different from the previous plan, where we will have hgc_openat and pass cmdserveropts.sockdirfd to it. That's because the current change is easier: chg has to pass a full path to "hg" as the "--address" parameter. There is no "--address-basename" or "--address-dirfd" flags. The next patch will remove "sockdirfd". Note: It'd be nice if we can use a native "connectat" implementation. However, that's not available everywhere. Some platform (namely FreeBSD) does support it, but the implementation has bugs so it cannot be used [2]. [1]: https://standards.freedesktop.org/basedir-spec/basedir-spec-latest.html [2]: https://www.mercurial-scm.org/pipermail/mercurial-devel/2016-April/082892.html

rebase: un-wrap function signature since it fits in 80 columns

py3: exclude pywatchman from test-check-py3-compat.t Exclude pywatchman from py3 test. They have already worked on Python 3 compatibility https://github.com/facebook/watchman/pull/247

py3: update test-check-py3-compat.t This part of test runs only on py3. This change was introduced by 16f4b341288d.

shelve: choose a legal shelve name when no name is passed (issue5112) Currently if our branch name contains '\' or starts with '.', shelve chooses an illegal shelve name. This behaviour is not good as it itself is choosing something which it won't accept further. We can raise errors if user passes a name which is illegal. After this patch, if '\' is contained in branch name or bookmark name, it will be replaced by '_' while choosing a shelve name and if they starts with '.', the first '.' is replaced by '_'.

shelve: add tests to ensure illegal shelve names are avoided We avoid '.' as the first letter of shelve name so that we don't create hidden file. We also avoid slashes in name so that we don't form a new directory

py3: replace sys.executable with pycompat.sysexecutable sys.executable returns unicodes on Python 3. This patch replaces occurences of sys.executable with pycompat.sysexecutable.

py3: have bytes version of sys.executable sys.executable on Python 3 returns unicodes and we want bytes. So this patch adds a new pycompat.sysexecutable which returns bytes by encoding using os.fsencode() since it is path variable.

py3: use pycompat.getcwd instead of os.getcwd