churn: add an usage example in docstring

tests: run test-check-py3-compat only in pure python mode This test was added few years ago to detect syntax and import related warnings and kickstart the python-3 porting efforts. It tries to parse the ast and import the module. When using in strict modes like `HGMODULEPOLICY=rust` or `HGMODULEPOLICY=c`, the test fails. Let's run the test only on pure python mode. We now have full test suite being run with python 3 and some people even use hg with python 3 in production (like me).

log: make -frREV PATH detect missing files before falling back to slow path If -rREV isn't specified, "log --follow" would abort on nonexistent paths. Let's implement this behavior for "-frREV" case as we have ctx.hasdir() now. Otherwise "log -frREV PATH" would silently fall back to slow path and files wouldn't be followed across renames. The loop is quadratic (as before), but the size of the startctxs and match.files() should be small in general. Some tests are marked as BROKEN since file renames aren't tracked in the slow path. This is a known limitation of the current history traversal function.

log: fix -fr'wdir()' PATH to follow newly added file Testing filelog doesn't make sense in this case because the file existence is tested against the specified changectxs. If the filelog is empty and if startctxs != [wctx], 'f not in c' should be triggered.

log: reorganize if-else and for loop in logcmdutil._makematcher() The test conditions are branchy depending on --follow and --rev options, so it should be better to switch first by --follow --rev. Note that revs is not empty so "if follow and startctxs" can be replaced with "if follow and opts.get(b'rev')".

merge: update commitinfo from all mergeresults during bid merge During bid merge, it's not clear which commitinfo should be stored and which one should not. This depends on which side the bid merge chooses for a file. For this we will need to refactor bid merge code and commitinfo handling. For now, we just blindly updates info since we hardly have any users of commitinfo and this will help us in testing and clearing out further path. Differential Revision: https://phab.mercurial-scm.org/D8965

merge: add missing ACTION_KEEP when both remote and ancestor are not present Previous patch may lead to confusion that the related criss-cross merge is consistent when done from any of the parents. However this is not true and we were missing setting an ACTION_KEEP. This patch now exposes that bid-merge favors ACTION_KEEP always and the result of merge is different when started from different parents. This change also effects a test case above where bid merge was wrongly picking `r` because it was missing keep related information from one of the ancestor. After this test, we are back in a state in the criss-cross merge tests where the result depends on which parent we are merging from. Differential Revision: https://phab.mercurial-scm.org/D8941

merge: store ACTION_KEEP_ABSENT when we are keeping the file absent locally If a file is not present on the local side, and it's unchanged between other merge parent and ancestor, we don't use any action, neither we had a if-else branch for that condition. This leads to bid-merge missing that there is a such action possible which can be performed. As test changes demonstrate, we now choose the locally deleted side instead of choosing the remote one consistently. This is also wrong behavior which is resulted because of missing possible action. It will be fixed in next patch. This whole logic is not acurrate as we should prompt user on what to do when this kind of criss-cross merge is in play. Differential Revision: https://phab.mercurial-scm.org/D8940

merge: add `ACTION_KEEP_ABSENT` to represent files we want to keep absent There are files which were deleted/not present in working copy parent but were present on other side of merge. On merge, we might decide to keep them deleted. We want to track such cases more closely, rather all kind of cases which results from some kind of merging logic. We do have `ACTION_KEEP` but having a dedicated action for the absent case is more cleaner. Initially I named the action as `ACTION_KEEP_DELETED` but later realized that file can be not-present because of other reasons than deletion like rename, hence decided to use more generic name `ACTION_KEEP_ABSENT`. Differential Revision: https://phab.mercurial-scm.org/D8974

mergeresult: introduce dedicated tuple for no-op actions This will help us in adding more no-op actions in next patch while keeping the code cleaner.

tests: add criss cross merging tests whose behavior need to be fixed Merging two changesets can mark a file as removed post merge. However, in some cases, a user might not want to remove that file and they revert the removal back and commit the merge. All this works perfectly well. However, when we do criss-cross merges with such merge where user explicitly choose to revert the removal with one where another user choose the removal, we does not get any conflict. The intent here is conflicting and merge should result in conflicts. One user merged and want to keep the file while other user merged and want to remove the file. Merging those merges should result in conflicts. This patch adds test cases for these cases. Differential Revision: https://phab.mercurial-scm.org/D8939

repo: avoid copying/updating a dict on every `repo.__getitem__` This has some mild performance benefits. I'm looking into a pathological case where one of our `hg log` invocations takes several seconds, and according to hyperfine this reduces the wall time of the entire operation (running in chg) from: ``` Time (mean ± σ): 7.390 s ± 0.106 s [User: 7.058 s, System: 0.271 s] Range (min … max): 7.300 s … 7.625 s ``` to: ``` Time (mean ± σ): 7.046 s ± 0.091 s [User: 6.714 s, System: 0.279 s] Range (min … max): 6.916 s … 7.169 s ``` Note: the log command is slow due to an issue in our custom stuff executing `repo[<arg>]` 298,800 times. This performance improvement is likely not noticeable during normal operation, but I don't feel like it's making the code more difficult to understand, and every small bit helps. Differential Revision: https://phab.mercurial-scm.org/D9022

obsstore: refactor v1 logic to fix 32 byte hash support Refactor the v1 logic to determine the node parsing based on the flag. Move the predecessor out of the fixed part and handle it like the other nodes, removing most of the duplicated code for parsing 20/32 bytes hashes. Differential Revision: https://phab.mercurial-scm.org/D8801

fsmonitor: increase the threshold before we recommend it, when using rust 50k files works just fine with the rust status, and it's annoying to get told "consider using fsmonitor" when we have another solution to the status speed. 400k files was not chosen in any rigorous way. I know 200k files is fine. Twice as many files should still be fine. Differential Revision: https://phab.mercurial-scm.org/D9021

copy-tracing: test case where a merge reverted a file deletion This case is currently broken for commit centric copy tracing. So we add an official case for it with a note about it being broken. Fixing it will requires multiples change in code related to merge, commit and copy tracing, so we introduce it beforehand for simplicity. Also, I have been sitting on this test for 3 months so I would rather have it upstream.

copy-tracing: test case where we go across a changed/deleted merge This case is currently broken in the commit centric case. So we add an official case for it with a note about it being broken. Fixing it will requires multiples change in code related to merge, commit and copy tracing, so we introduce it beforehand for simplicity. Also, I have been sitting on this test for 3 months so I would rather have it upstream.

merge: show list of bids for each file in bid-merge in ui.debug() Earlier, we were showing the list of bids only when we were ambiguously picking. However, the cases where we unambiguously picked a side may not always be correct and need to be fixed. Having list of bids for all files will be helpful in debugging. Differential Revision: https://phab.mercurial-scm.org/D8966

merge with stable

cmdutil: reimplement finddate() without using walkchangerevs() It's simpler and slightly faster maybe because a fewer Python ops would run. Unscientific benchmark: $ python -m timeit \ -s 'from mercurial import hg, ui, cmdutil; repo = hg.repository(ui.ui())' \ 'cmdutil.finddate(repo.ui, repo, "<2008-01-01")' (orig) 10 loops, best of 3: 1.45 sec per loop (new) 10 loops, best of 3: 1.25 sec per loop Now "hg churn" and "hg grep" are the only users of walkchangerevs(), which I want to refactor and fix bugs.

test-simple-update: add test for -d DATE option I couldn't find any tests for cmdutil.finddate() except for the abort case.

largefiles: walk history in ascending order while downloading all lfiles I don't think the order matters. Maybe it's purely because of the use of walkchangerevs(), which was originally designed for "hg log" command. Surprisingly, the number of objects fetched in test-largefiles.t has changed. According to the --verbose output, the order of the following fetches flipped and the latter got deduplicated. getting large3:eb7338044dc27f9bc59b8dd5a246b065ead7a9c4 found eb7338044dc27f9bc59b8dd5a246b065ead7a9c4 in store getting sub/large4:eb7338044dc27f9bc59b8dd5a246b065ead7a9c4 found eb7338044dc27f9bc59b8dd5a246b065ead7a9c4 in store

largefiles: replace use of walkchangerevs() with simple revset query Since it does nothing in prepare(), what we're doing is just walking revisions matching ".hglf" in reverse order.

largefiles: remove unused 'rev' parameter from downloadlfiles() It's no longer used since 83ead8cb0ff2 "largefiles: implement pull --all-largefiles as a special case of --lfrev."

resourceutil: document when we expect to take the importlib.resouces code path Differential Revision: https://phab.mercurial-scm.org/D9018

templater: fix reading of templates in frozen binaries with py3 < 3.7 When using a frozen binary with py3 < 3.7, there's no `importlib.resources` module, so we use the code path that reads the resources from the file system. That code path expects bytes for package name and resource name. Differential Revision: https://phab.mercurial-scm.org/D9008

histedit: cache description line Navigating the curses-based histedit interface can be pretty slow because it redraws everything whenever you make a change. This patch simply replaces `@property` by `@util.propertycache` on the `histeditrule.desc()` function so it's not re-calculated every time the screen needs to be re-rendered. I timed it on an example of 30 simple commits, where I moved the top commit down 25 steps and then up 25 steps after. Before this patch, that (the whole `hg histedit` invocation) took 11.6 s of CPU and after this patch it took 0.8 s). Differential Revision: https://phab.mercurial-scm.org/D9016

tests: make emacs test less strict It was failing like this for me: ``` @@ -2,7 +2,7 @@ $ emacs -q -no-site-file -batch -l $TESTDIR/../contrib/hg-test-mode.el \ > -f ert-run-tests-batch-and-exit Running 1 tests (*) (glob) - passed 1/1 hg-test-mode--compilation-mode-support + passed 1/1 hg-test-mode--compilation-mode-support (0.045732 sec) - Ran 1 tests, 1 results as expected (*) (glob) + Ran 1 tests, 1 results as expected, 0 unexpected (2020-09-11 16:49:56+0000, 0.046034 sec) ``` Differential Revision: https://phab.mercurial-scm.org/D9017

graphlog: use '%' only if there are *unresolved* conflicts In 14d0e89520a2, I made graphlog use '%' for the "other" context when there's an existing merge state. However, that has confused many people because it shows up even if all conflicts are already resolved, which makes it show up even after e.g. `hg update -m` with automatically resolved conflicts. This patch makes it so we show the '%' only if there still unresolved conflicts. This patch replaces my earlier attempt in D8930, where I decided to automatically clear the mergestate if there are no remaining conflicts. That had the problem that it wouldn't let the user re-resolve the conflicts using `hg resolve`. Note that an in-progress "proper" merge (one that will result in a commit with two parents, such as after `hg merge`) will already have two dirstate parents before the commit happens. That means that both sides of the merge will get drawn as '@' in the graph, since "is dirstate parent" takes precedence over "is involved in merge conflict". Differential Revision: https://phab.mercurial-scm.org/D9007

merge: show number of ancestors in bid merge debug notes A good number of times, we don't generate an action for a file in manifestmerge() which can result in bid merge doing the wrong thing. Mentioning the number of ancestors from which we are bidding will help spot such cases where we are not returning an action. Differential Revision: https://phab.mercurial-scm.org/D8967

debugmergestate: sort extras before printing Prevents flaky output. Differential Revision: https://phab.mercurial-scm.org/D8986

debugmergestate: show extras for files which are not in mergestate With recent changes and future changes, we will like to store extras information about files which were merged automatically. Hence, we will have merge extras for files which are not in the mergestate. Differential Revision: https://phab.mercurial-scm.org/D8942

tests: update lockdelay.py to handle the `wait` argument Spotted by a future change.

commit: pass mergestate into _filecommit() instead of re-reading it mergestate reading although cheap is not free. Let's read mergestate once on top and pass it into `_filecommit()`. In upcoming patches, we will be reading mergestate more in `_filecommit()`. Differential Revision: https://phab.mercurial-scm.org/D8984

py3: fix bytes and str mixup in run-tests Differential Revision: https://phab.mercurial-scm.org/D9009

hg-core: fix some `clippy` warnings Differential Revision: https://phab.mercurial-scm.org/D8957

rhg: print error message when argument parsing fails Differential Revision: https://phab.mercurial-scm.org/D8956

rhg: fix `clippy` warnings Differential Revision: https://phab.mercurial-scm.org/D8955

rhg: pass `ui` to `Command` `run` Allow implementation of `From<clap::ArgMatches> for Command` Differential Revision: https://phab.mercurial-scm.org/D8954

rhg: add harness tests for rhg files Differential Revision: https://phab.mercurial-scm.org/D8873

rhg: make output of `files` relative to the current directory and the root This matches the behavior of `hg files`. The util is added in `hg-core` instead of `rhg` because this operation could be useful for other external tools. (this was definitely not prompted by rust issue #50784, I swear) Differential Revision: https://phab.mercurial-scm.org/D8872

tags: take lock instead of wlock before writing hgtagsfnodes1 cache This cache is shared across stores and hence we should take store lock before writing to it. Otherwise there will be race where one share with wlock is writing to this cache and other share with wlock is trying to read it simultaneously. Differential Revision: https://phab.mercurial-scm.org/D9001

statichttprepo: use LockUnavailable() instead of Abort() for lock (API) If we try to get a lock on statichttprepo, we get `error.Abort()` instead of subclass of `error.LockError()`. The callers which catches `error.LockError` fails to catch this case as the correct error is not raised. Raising `error.LockUnavaible()` is same as what is done for wlock also.

localrepo: warn if we are writing to cache without a lock From quite sometime we have two types of cache, `cache` and `wcache`. The later one is a working copy cache and the first one is a store cache. Let's add a check for warning if we are missing store lock while writing to these caches. This is inspired from some tag cache breakage which is observed when multiple shares are in play. The interesting part is that although we are still taking wlock to write store caches at many places, but still the test pases. Differential Revision: https://phab.mercurial-scm.org/D9000

commit: fix a wrong argument name in documentation Differential Revision: https://phab.mercurial-scm.org/D8985

git: remove unrequired assignment of listignored and listunknown Caught by test-check-pyflakes.t

grep: fix hash(linestate) to not include linenum linestate.__eq__() just compares the line values whereas __hash__() does hash both self.line and self.linenum, which violates the rule. __hash__() was added at fb502719c75c, "python 2.6 compatibility: add __hash__ to classes that have __eq__" with no additional remarks, so this would probably be a simple mistake. The test output changed because difflib.SequenceMatcher() internally uses a dict. As you can see, the line "export" is unchanged at the revision 2, so the new output is correct.

test-grep: document that trivially moved lines might not be detected I'm not going to fix this. I just learned "grep --diff" does clever thing than a simple grep(patch.diff(context=0)), and I think it's better to document how things work.

revset: remove indirect indexing of status tuple Just use the attribute name.

rewriteutil: relax the sha1 hash references to handle future hash types Per discussion with nbjoerg in IRC. Differential Revision: https://phab.mercurial-scm.org/D8951

phabricator: update the hashes in commit messages as they get submitted Due to the sequence of actions (posting, amending the local commit, and then updating the Differential properties), the message in the commit is updated on the initial send but the message displayed in Phabricator is not. It should get updated there if the review is reposted. The data in the Commits tab is accurate for the first `phabsend`. Differential Revision: https://phab.mercurial-scm.org/D8950

rewriteutil: also consider pending obsoletes when updating hashes in messages Phabricator builds up the replacement commits and mapping in a single transaction, and then finalizes everything once the commits have been rewritten. That's too late when trying to update the messages for those commits. I'm a little concerned that this isn't a generic enough interface, since it doesn't mimic the list of list return of `obsutil.successorssets()`. But this is the type of mapping that phabricator maintains, and I don't think the methods that would be interested in calling this need to worry about split and divergence. We can fix that later if the need arises. Differential Revision: https://phab.mercurial-scm.org/D8949

rewriteutil: extract evolve code used to replace obsolete hashes in commits The evolve command uses it, but there are core things like `phabsend` and `rebase` that would also benefit. Differential Revision: https://phab.mercurial-scm.org/D8948

git: fix index handling of removed files during commit (issue6398) Other changes in this series also changed the behavior here in positive ways, but this was the final step that actually fixed things. Differential Revision: https://phab.mercurial-scm.org/D8999

git: make dirstate actually support listclean parameter As far as I can tell listignored and listunknown should already work. I'm vexed that there doesn't seem to be a way to get clean files out of the pygit2 status method, but this at least makes things work better. Differential Revision: https://phab.mercurial-scm.org/D8998

git: make dirstate status() respect matcher As with other changes in this stack, we appear to have been getting lucky in the past. An upcoming change behaved _very_ oddly without this fix. Differential Revision: https://phab.mercurial-scm.org/D8997

git: fix up dirstate use of index This was super-broken before, and somehow none of the existing attempts to use this code tripped on the defects here. Sigh. Differential Revision: https://phab.mercurial-scm.org/D8996

git: correctly handle "nothing changed" commits I guess localrepo.commit() actually returns an Optional[node], which is a bit of a surprise to me. Differential Revision: https://phab.mercurial-scm.org/D8995

localrepo: use functools.wraps() in unfilteredmethod decorator This makes it easier to figure out what function you're holding on to when doing printf-style debugging. Differential Revision: https://phab.mercurial-scm.org/D8994

git: actually copy treemanifest instances in .copy() (issue6398) The implementation here is so simple I honestly have no idea why I didn't do it at the time. Hopefully there's not some nuance past-me forgot to write down. Differential Revision: https://phab.mercurial-scm.org/D8993

git: restore basic functionality after b3040b6739ce We don't yet have a formal interface for the changelog, but it's mostly specified. Sadly, b3040b6739ce added a semi-private pseudo-enum that we need to cope with, so it's probably high time that someone (me?) attempts to define that interface to prevent future backsliding. Differential Revision: https://phab.mercurial-scm.org/D8992

git: convert tz offset to int (issue6359) Differential Revision: https://phab.mercurial-scm.org/D8991

merge with stable

extdiff: refactor cmdline and gui calculation login in a separate fn This is some good logic with handling of many config items and various ways of specifying it. I want to reuse in `diff --tool` and hence refatcored it in a separate function of it's own.

extdiff: reorder an if-else conditional This brings continue part on top and will help in next patch where we will like to introduce utility functions for rest of the code.

run-tests: extract logic to get errpath in a utility func Differential Revision: https://phab.mercurial-scm.org/D8979

run-tests: refactor filtering logic for --retest flag How I got to this: While re-running failed tests using --retest I noticed that the output: "running x tests using y parallel processes". was not actually correct, because x was the total number of tests present in the directory, but it should be the number of failed tests. Although it would run only the failed tests and later will say that remaining tests were skipped. Changes in test files reflect the fixed behaviour. This patch change and move the logic for filtering failed test for --retest option and make sure that we create instances of class Test only for the tests we need to run. As mentioned in the deleted text (in this patch itself) the logic for --retest should be outside of TestSuite. Differential Revision: https://phab.mercurial-scm.org/D8938

tests: add a --retest test to demonstrate a fix in next patch As you see above the added lines, there was only one test failed. So the output should be: "running 1 tests using 1 parallel processes" Next patch will be fixing this. Differential Revision: https://phab.mercurial-scm.org/D8964

tests: remove a sub-test since we are done with it in test-run-tests.t removing test-failure.t to make sure that in next patch when we re-run failed tests using --retest, it won't get considered unnecessarily. Differential Revision: https://phab.mercurial-scm.org/D8963

storageutil: allow modern hash sizes for fileids Differential Revision: https://phab.mercurial-scm.org/D8783

registrar: fix a documentation typo Differential Revision: https://phab.mercurial-scm.org/D8976

documentation: add `zstd` compression to the internal `revlogs` documentation Differential Revision: https://phab.mercurial-scm.org/D8953

extdiff: move single file handling inside `not per-file` conditional If `--per-file` is passed, we will diffing files one by one, hence there is no need to make this optimization around single file in that case. This optimization is only required when `--per-file` is not passed and we will be opening directory-diff for a single file. Differential Revision: https://phab.mercurial-scm.org/D8971

extdiff: remove dir2root and pass full path as dir2 in _runperfilediff() The only use of `dir2root` was to join with `dir2` to generate the path for other side of diff. Like in previous patch, `dir1a` and `dir1b` are full paths and no longer base names, hence we pass `dir2` as full path too and making `dir2root` unrequired. Differential Revision: https://phab.mercurial-scm.org/D8970

extdiff: pass full paths of `dir1a` and `dir1b` to `_runperfilediff()` Earlier we were passing basename instead of the fullpath and then joining with the tmproot. This is wrong because the user can choose `rev1a` as wdir and in those cases, tmproot should not be joined with the path. I am working on refactoring extdiff logic so that we can have options like `diff --tool` and encountered this. Although this patch in itself makes no difference, however in future when a new caller of `_runperfilediff()` will be added, it will be useful to directly pass on the full paths instead. Differential Revision: https://phab.mercurial-scm.org/D8969

merge with stable

mercurial: force LF endings for *.py, *.{c,h} and *.t in .editorconfig PyCharm on Windows otherwise uses CRLF. Differential Revision: https://phab.mercurial-scm.org/D8947

hooklib: update documentation of changeset_obsoletedfor for changed hook type This updates usage example of changeset_obsoleted to reflect the move from pretxnclose to txnclose made in 04ef381000a8 (hooklib: fix detection of successors for changeset_obsoleted). Differential Revision: https://phab.mercurial-scm.org/D8929

worker: don't expose readinto() on _blockingreader since pickle is picky The `pickle` module expects the input to be buffered and a whole object to be available when `pickle.load()` is called, which is not necessarily true when we send data from workers back to the parent process (i.e., it seems like a bad assumption for the `pickle` module to make). We added a workaround for that in https://phab.mercurial-scm.org/D8076, which made `read()` continue until all the requested bytes have been read. As we found out at work after a lot of investigation (I've spent the last two days on this), the native version of `pickle.load()` has started calling `readinto()` on the input since Python 3.8. That started being called in https://github.com/python/cpython/commit/91f4380cedbae32b49adbea2518014a5624c6523 (and only by the C version of `pickle.load()`)). Before that, it was only `read()` and `readline()` that were called. The problem with that was that `readinto()` on our `_blockingreader` was simply delegating to the underlying, *unbuffered* object. The symptom we saw was that `hg fix` started failing sometimes on Python 3.8 on Mac. It failed very relyable in some cases. I still haven't figured out under what circumstances it fails and I've been unable to reproduce it in test cases (I've tried writing larger amounts of data, using different numbers of workers, and making the formatters sleep). I have, however, been able to reproduce it 3-4 times on Linux, but then it stopped reproducing on the following few hundred attempts. To fix the problem, we can simply remove the implementation of `readinto()`, since the unpickler will then fall back to calling `read()`. The fallback was added a bit later, in https://github.com/python/cpython/commit/b19f7ecfa3adc6ba1544225317b9473649815b38. However, that commit also added checking that what `read()` returns is a `bytes`, so we also need to convert the `bytearray` we use into that. I was able to add a test for that failure at least. Differential Revision: https://phab.mercurial-scm.org/D8928

commit: clear mergestate also with --amend (issue6304) The `hg commit --amend` uses the in-memory code, which naturally doesn't touch the merge state (well, it shouldn't anyway; I think I've fixed bugs in that area recently). We therefore need to clear the mergestate after calling `repo.commitctx()` since we expect that from `hg commit --amend`. Differential Revision: https://phab.mercurial-scm.org/D8932

tests: add test showing that merge state is not cleared by amend This is slightly modified version of the test case I provided in issue6304. Differential Revision: https://phab.mercurial-scm.org/D8931

requirements: introduce constants for `shared` and `relshared` requirements We add them to `WORKING_DIR_REQUIREMENTS` too as they should be stored in `.hg/requires` and have information about the type of working copy. Differential Revision: https://phab.mercurial-scm.org/D8926

mergestate: replace `addmergedother()` with generic `addcommitinfo()` (API) Storing that a file is resolved for the other parent while merging is just one case of things we will like to store in the mergestate. There are more which we will like to store. This patch replaces `addmergedother()` with a much more generic `addcommitinfo()`. Doing this, we also blinding stores the same key value pair generated by the merge code instead of touching them. Differential Revision: https://phab.mercurial-scm.org/D8923

merge: introduce `addcommitinfo()` on mergeresult object This makes code little bit nicer as we directly update information in the mergeresult object instead of building up a dict first and then setting it. Differential Revision: https://phab.mercurial-scm.org/D8922

merge: use collections.defaultdict() for mergeresult.commitinfo We will be storing info from mergeresult.commitinfo to mergestate._stateextras in upcoming patches, let's make them use same structure so that we don't have to make much efforts in transferring info from one to other. Differential Revision: https://phab.mercurial-scm.org/D8921

mergestate: use _stateextras instead of merge records for commit related info There is a set of information related to a merge which is needed on commit. We want to store such information in the mergestate so that we can read it while committing. For this purpose, we are using merge records and introduced a merge entry state for that. However this won't scale and is not clean way to implement this. This patch reworks the existing logic related to this to use _stateextras and read from it. Right now the information stored is not very descriptive but it will be in next patch. Using _stateextras also makes MERGE_RECORD_MERGED_OTHER useless and only to be kept for BC. Differential Revision: https://phab.mercurial-scm.org/D8920

mergestate: use collections.defaultdict(dict) for _stateextras I want to use this _stateextras more in upcoming patches to store some commit time related information. Using defaultdict will help in cleaner code around checking whether a file exists or not. Differential Revision: https://phab.mercurial-scm.org/D8919

hgweb: minimize scope of a try-block in staticfile() I think the exceptions are only relevant for the `os.stat()` and `open()` calls, and maybe to the `fh.read()` call. Differential Revision: https://phab.mercurial-scm.org/D8936

hgweb: ignore web.templates config when guessing mime type for static content Frozen binaries won't have a file-system path for static content, so I'd like to remove dependence on that. From the documentation, it seems like `mimetypes.guess_type()` only cares about the suffix, so I think it should be enough to pass in just path under the `web.templates` directory. Differential Revision: https://phab.mercurial-scm.org/D8935

hgweb: let staticfile() look up path from default location unless provided This reduces duplication between the two callers. Differential Revision: https://phab.mercurial-scm.org/D8934

hgweb: handle None from templatedir() equally bad in webcommands.py The following paragraph is based just on my reading of the code; I have not tried to test it. Before my recent work on templates in frozen binaries, it seems both `hgwebdir_mod.py` and `webcommands.py` would pass in an empty list into `staticfile()` when running in a frozen binary. That would then result in a variable in that function (`path`) not getting bound before its first use. I then changed that without thinking in D8786 so we passed a `None` value into the function, which made it break in another way (trying to iterate over `None`). Then I tried to fix it up in D8810, but I only changed `hgwebdir_mod.py` for some reason, and it still doesn't actually work in frozen binaries (which seems fair, since was broken before my changes too). This patch just replicates the half-assed "fix" from D8810 in `webcommands.py`, so they look more similar so I can start refactoring them in the same way. Differential Revision: https://phab.mercurial-scm.org/D8933

posixworker: avoid creating workers that end up getting no work If `workers` (the detected or configured number of CPUs) is greater than the number of work items, then some of the workers end up getting 0 work items. Let's not create such workers. Differential Revision: https://phab.mercurial-scm.org/D8927

revert: remove dangerous `parents` argument from `cmdutil.revert()` As we found out the hard way (thanks to spectral@ for figuring it out!), `cmdutil.revert()`'s `parents` argument must be `repo.dirstate.parents()` or things may go wrong. We had an extension that passed in the target commit as the first parent. The `hg split` command from the evolve extension seems to have made the same mistake, but I haven't looked carefully. The problem is that `cmdutil._performrevert()` calls `dirstate.normal()` on reverted files if the commit to revert to equals the first parent. So if you pass in `ctx=foo` and `parents=(foo.node(), nullid)`, then `dirstate.normal()` will be called for the revert files, even though they might not be clean in the working copy. There doesn't seem to be any reason, other than a tiny performance benefit, to passing the `parents` around instead of looking them up again in `cmdutil._performrevert()`, so that's what this patch does. Differential Revision: https://phab.mercurial-scm.org/D8925

requirements: introduce a set of working directory specific requirements Some requirements like the SPARSE_REQUIREMENT is working directory specific and cannot be shared. We add a set which will contain all these requirements. This is not the best we can do, I think having a rich requirement class will be much better but that will be out of scope for this series. Differential Revision: https://phab.mercurial-scm.org/D8924

localrepo: move requirements constant to requirements module We now have a dedicated module for requirements constant, let's move the ones in localrepo there. Differential Revision: https://phab.mercurial-scm.org/D8918

requirements: introduce new requirements related module It was not clear where all requirements should and related APIs should be, this patch introduces a requirements module which will have all exitsing requirements and related APIs. Differential Revision: https://phab.mercurial-scm.org/D8917

repository: introduce constant for treemanifest requirement and use it In future we will like to much cleaner logic around which requirement is for working copy and which can go in store. To start with that, we first need to de-clutter the requirement values spread around and replace them with constants. Differential Revision: https://phab.mercurial-scm.org/D8916

tests: make flag parsing test more future safe The revlog format contains a number of feature flags, e.g. if general deltas are active. When testing that unknown flags are rejected, use bits that are not immediately following the currently used bits. Differential Revision: https://phab.mercurial-scm.org/D8782

rename: add support for --at-rev, which marks as copy and removes the source I had previously only added support for `--at-rev` to `hg cp`, but not to `hg mv`. This patch adds that support. Just like for `hg cp`, it marks the destination as copied from the source, and doesn't care if the source file still exists (because it only supports the `-A` mode, aka "don't touch files" mode). It works whether or not the source file still exists. This matches the behavior of `hg mv -A` in the working copy. Differential Revision: https://phab.mercurial-scm.org/D8840

tests: make test-install.t work on debian systems Debian systems, at least as of their version of python3.8 on my machine, have rewritten some logic in ensurepip to make it not use the wheels in pip._bundled, but instead to use wheels installed in /usr/share/python-wheels. It copies these wheels into the virtual environment when it's created, and installenv/bin/pip is able to see them and use them, so it thinks that 'wheel' is installed, and that it can build the mercurial wheel instead of just installing it. For some reason, when it subprocesses to run `python3 setup.py bdist_wheel`, it setup.py does *not* have the 'wheel' wheel available, and we get an error message. Differential Revision: https://phab.mercurial-scm.org/D8813

rhg: handle broken pipe error for stderr Differential Revision: https://phab.mercurial-scm.org/D8871

rhg: extract function handle_stdout_error Avoid repeating the logic of handling stdout write errors. Differential Revision: https://phab.mercurial-scm.org/D8870

rhg: add a limited `rhg files` subcommand Differential Revision: https://phab.mercurial-scm.org/D8869

rhg: add a `Files` `Command` to prepare the `rhg files` subcommand Differential Revision: https://phab.mercurial-scm.org/D8868

rhg: simplify `FindRootError` handling Differential Revision: https://phab.mercurial-scm.org/D8867

rhg: add buffered stdout writing possibility Improve batch stdout writing performance. At some point line buffered output should be introduced. Differential Revision: https://phab.mercurial-scm.org/D8866

rhg: ask the error message from `CommandError` Avoid repeating the display of the same error messages in different commands. Differential Revision: https://phab.mercurial-scm.org/D8865

rhg: Do not return error when when we really mean ok in commands Before when a command was successfull `Err(CommandErrorKind::Ok.into())` was returned which is an oxymoron. Using `Ok(())` when everything is ok seems more appropriate. Differential Revision: https://phab.mercurial-scm.org/D8864

hg-core: define a `ListTrackedFiles` `Operation` List files under Mercurial control in the working directory. Differential Revision: https://phab.mercurial-scm.org/D8863

hg-core: remove the `Operation` trait There is no way to currently define a trait which can both return references to `self` and to passed data, which is what we would need. Generic Associated Types may fix this and allow us to have a unified interface. See: rust #44265 Differential Revision: https://phab.mercurial-scm.org/D8862

hg-core: make parse_dirstate return references rather than update hashmaps Returing a vec is faster than updating a hashmap when the hashmap is not needed like in `hg files` which just list tracked files. Returning references avoid copying data when not needed improving performence for large repositories. Differential Revision: https://phab.mercurial-scm.org/D8861

repository: introduce constant for internal phase repo requirement and use it In future we will like to much cleaner logic around which requirement is for working copy and which can go in store. To start with that, we first need to de-clutter the requirement values spread around and replace them with constants. Differential Revision: https://phab.mercurial-scm.org/D8912

repository: introduce constant for sparse repo requirement and use it In future we will like to much cleaner logic around which requirement is for working copy and which can go in store. To start with that, we first need to de-clutter the requirement values spread around and replace them with constants. Differential Revision: https://phab.mercurial-scm.org/D8911

localrepo: refactor `.hg/requires` reading logic in separate function In an upcoming patch, we will be reusing this to read `.hg/store/requires`, so let's separate it in a different function before. Differential Revision: https://phab.mercurial-scm.org/D8910

localrepo: refactor logic to calculate sharedvfs in separate fn We will be reusing this in an upcoming patch, so better to refactor it into a separate function. Also the underlying handling deserves a function of it's own. Differential Revision: https://phab.mercurial-scm.org/D8909

store: refactor space delimited list to proper data structure There is no good reason why are having a space delimited list and then using `.split()` to get the actual list. Let's convert this into a proper collection. Differential Revision: https://phab.mercurial-scm.org/D8908

makefile: stop setting unused HGEXTDIR variable during osx build The variable was added in a38ed42cd23c (osx: include chg by default, 2017-03-20), but I can't find any others references to the variable in that commit or in any other commits. Differential Revision: https://phab.mercurial-scm.org/D8915

merge: drop commitinfo argument to applyupdates (API) We now pass the mergeresult object and hence there is no need to have a separate commitinfo argument as the required info is present in mergeresult object. Differential Revision: https://phab.mercurial-scm.org/D8904

merge: remove emptyactions() and use collections.defaultdict(list) instead emptyactions() used to return a dict which was populated and passed into applyupdates(). However, with recent changes, we no longer pass a plain dict, instead we pass the mergeresult object. There was only one usage of emptyactions and that too inside mergeresult object. That usage is replaced with collections.defaultdict(list) instead. Not sure why we were not using collections.defaultdict(list) from the beginning. Differential Revision: https://phab.mercurial-scm.org/D8903

merge: pass mergeresult obj in _forgetremoved() (API) Instead of returning a dict of actions and then updating it, let's pass the object directly and update it there. This makes `updateactions()` on mergeresult unused and this patch removes that. After this patch, we have couple of methods left on mergeresult class which still exposes the internal dict based action storage. Differential Revision: https://phab.mercurial-scm.org/D8889

mergeresult: introduce filemap() which yields filename based mapping We wanted to remove `actions` as this was leaking how we store things internally and was direct access to one of the member. This introduces filemap() which yields a map of `filename` -> `action, args, msg`. `mergeresult.actions` has been deleted as it's no longer required. Differential Revision: https://phab.mercurial-scm.org/D8888