merge with stable

procutil: move comment closer to relevant code

procutil: use mercurial.windows.winstdout only on Python 2 and TTYs Python 3 already works around the bug. The workaround is only needed when writing to consoles. If stdout is a console, sys.stdout.isatty() is true.

procutil: split if condition This prepares the code for subsequent changes where we need to differentiate between the two cases.

procutil: explain better why line buffering is not possible The sentence “On Python 3, buffered binary streams can't be set line-buffered.” was imprecise, as all streams are just Python classes and we can implement our own (which we did).

tests: make subprocess handling reusable for different tests in test-stdio.py

procutil: back out 8403cc54bc83 (make ....procutil.stderr unbuffered) Changeset 8403cc54bc83 introduced code that opens a second file object referring to the stderr file descriptor. This broke tests on Windows. The reason is that on Windows, sys.stderr is buffered and procutil.stderr closed the file descriptor when it got garbage collected before sys.stderr had the chance to flush buffered data. `procutil.stdout` had the same problem for a long time, but we didn’t realize, as in CI test runs, stdout is not a TTY and in this case no second file object is opened.

test-clone-uncompressed: use config to silence the lock warning The ui.timeout.warn option can solve the issue6237 in a cleaner way than what was done in 752da6863e39. That way, possible other unexpected error output will not be silenced. Differential Revision: https://phab.mercurial-scm.org/D8726

hooklib: fix detection of successors for changeset_obsoleted Provide a hook for obsutil.getobsolete to be used with either a transaction or the changes item of the transaction, since hooks only have access to the latter. Use that to find the correct list of revisions with obsmarkers, even new ones, and then filter out revisions with known successors. Move the processing from pretxnclose to txnclose as the transaction access itself is no longer necessary. This is more in line with notify and ensures that sanity checks can abort the transaction first. Differential Revision: https://phab.mercurial-scm.org/D8575

fix: prefetch file contents This prevents the worker subprocesses from contacting the server individually, which is either inefficient, or leads to problems if the connection is shared among them. Differential Revision: https://phab.mercurial-scm.org/D8723

fix: obtain base paths before starting workers This moves calculation of base paths to before work is dispatched. While this does mean that copy tracing will be serialized instead of parallel, it is necessary to be able to prefetch the base contents in a batch, which will likely be more efficient. Differential Revision: https://phab.mercurial-scm.org/D8722

scmutil: allowing different files to be prefetched per revision The old API takes a list of revision separate from the file matcher, and thus provides no way to fetch different sets of files from each revision. In preparation for adding one such usage, I'm changing the API to take a list of (revision, file matcher) tuples instead. Differential Revision: https://phab.mercurial-scm.org/D8721

tests: update test-devel-warnings.t output with chg

tests: make names in test-stdio.py more distinctive This way, more tests can be added without name clashes.

tests: terminate subprocess in test-stdio.py in case of exception If an error happened while reading the output of the subprocess, the pipe / TTY buffer can fill up and prevent that the subprocess ends. Therefore we should terminate the subprocess in case of an exception.

tests: proof test-stdio.py against buffer fill-up With the previous code, it could in theory happen that the pipe / PTY buffer of the child stdout / stderr fills up and the process never finishes. To prevent that, we read all of the stream before waiting for the end of the process. To ensure that the stream reaches EOF when the child finishes, we must close the parent "copy" of the child stdout / stderr.

tests: stablize test-serve.t on Windows I forget the reason that the subprocess on Windows doesn't print this, but all other instances of this are similarly conditionalized, so I didn't think too hard about it. Also, the server needs to be killed so it doesn't prevent the next run from working, especially since the port isn't randomized. Differential Revision: https://phab.mercurial-scm.org/D8720

commitctx: document the manifest writing function Same spirit as for `_filecommit` lets document the input and output before making any change or improvement. This is part of a larger refactoring/cleanup of the commitctx code to clarify and augment the logic gathering metadata useful for copy tracing. The current code is a tad too long and entangled to make such update easy. We start with easy and small cleanup. Differential Revision: https://phab.mercurial-scm.org/D8705

commitctx: reorder some conditional for efficiency in _filecommit Checking if a dict is empty will be faster than comparing text. I don't expect it to be a huge performance win, but still a good (but gratuitous) cleanup to do while we are at it. This is part of a larger refactoring/cleanup of the commitctx code to clarify and augment the logic gathering metadata useful for copy tracing. The current code is a tad too long and entangled to make such update easy. We start with easy and small cleanup. Differential Revision: https://phab.mercurial-scm.org/D8701

commitctx: document _filecommit input and output This is the beginning of a larger refactoring/cleanup of the commitctx code to clarify and augment the logic gathering metadata useful for copy tracing. The current code is a tad too long and entangled to make such update easy. We start with easy and small cleanup. Differential Revision: https://phab.mercurial-scm.org/D8699

phases: replace magic number by constant Differential Revision: https://phab.mercurial-scm.org/D8695

clonebundles: optional memory-requirement attribution The new REQUIREDRAM option allows a client to skip bundles it isn't expected to handle well, e.g. without swapping. This allows a fallback path to be provided e.g. using zstd level 10 instead of 22. Differential Revision: https://phab.mercurial-scm.org/D8645

util: provide a helper function to estimate RAM size For POSIX systems, it uses sysconf. For Windows, it uses the win32 API directly. Differential Revision: https://phab.mercurial-scm.org/D8644

tests: allow timing difference in output Differential Revision: https://phab.mercurial-scm.org/D8676

documentation: add some internals documentation about bid merge This is an important algorithm that was only documented on the wiki so far. Some update to the algorithm (and associated doc) is to expected in the future since the bid merge algorithm is bug-ridden when it comes to file deletion comes to play. Differential Revision: https://phab.mercurial-scm.org/D8711

cmdserver: document message-encodings and channel output options While writing the previous patch, I noticed these options are undocumented. In my testing, a separate status/error message channel works well in GUI frontend as we no longer have to sort out data and message from mixed outputs. So let's mark it as not experimental.

cmdserver: add option to not exit from message loop on SIGINT Sending SIGINT to server is the only way to interrupt a command running in command-server process. SIGINT will be caught at dispatch.dispatch() if we're lucky. Otherwise it will terminate the serer process. This is fundamentally unreliable as signals are delivered asynchronously. "cmdserver.shutdown-on-interrupt=False" mitigate the issue by making the server basically block SIGINT.

pycompat: remove pycompat.{stdin,stdout,stderr} All users have been changed to use procutil.{stdin,stdout,stderr}, which provide consistent behavior across platforms and Python versions.

pycompat: change users of pycompat.{stdin,stdout,stderr} to use procutil.std* On Python 3, pycompat.{stdin,stdout,stderr} are usually block-buffered even if connected to a TTY. procutil.{stdin,stdout,stderr} provide consistent behavior across platforms and Python versions.

hgignore: add mypy cache files Differential Revision: https://phab.mercurial-scm.org/D8692

revlog: avoid hard-coded hash sizes Differential Revision: https://phab.mercurial-scm.org/D8683

test: restore expected output in test-persistent-nodemap.t The merge 78cafd48b9b2 had a small error and wrongly dropped the output updated from one side of the merge. This changeset re-install it. Differential Revision: https://phab.mercurial-scm.org/D8678

heptapod-ci: build rhg before tests run Differential Revision: https://phab.mercurial-scm.org/D8682

rhg: add a limited `rhg root` subcommand Clap has been choosen for argument parsing for the following reasons: - it's a wildly used and maintained crate - it can deal with OS encoding making it suitable for any encoding - it supports nonambiguous prefix matching as already available in hg - it will soon allow for structopts-style declarative pattern instead of the currently used builder pattern Differential Revision: https://phab.mercurial-scm.org/D8613

rhg: add RootCommand using hg-core FindRoot operation to prepare `hg root` The println macro is not used to avoid string usage. Dealing only with bytes allows us to be compatible with any encoding and not just UTF8. Later on, format macro will be made to have more readable code. Differential Revision: https://phab.mercurial-scm.org/D8612

archival: abort if compression method is unavailable `tarfile.CompressionError` is documented to be the "exception for unavailable compression methods". Also, make tests conditional on whether the lzma module is available or not.

demandimport: ignore `lzma` module for demandimport This makes importing the module fail if the `_lzma` module is not present. This makes e.g. tarfile correctly recognize if LZMA support is not present. It changes the exception File "/usr/lib/python3.6/tarfile.py", line 1694, in xzopen fileobj = lzma.LZMAFile(fileobj or name, mode, preset=preset) AttributeError: module 'lzma' has no attribute 'LZMAFile' to the more correct exception File "/usr/lib/python3.6/tarfile.py", line 1692, in xzopen raise CompressionError("lzma module is not available") tarfile.CompressionError: lzma module is not available Also, it prevents that the error "abort: No module named '_lzma'!" is shown when a development warning is to be shown. The reason why that happened is that for showing the warning, we get information about the stack frames from the inspect module, which accesses the `__file__` attribute of all modules in `sys.modules` to build some cache, causing all modules (including `lzma`) to be imported.

merge with stable

procutil: make mercurial.utils.procutil.stderr unbuffered For most Mercurial code, it doesn’t make a difference, as the ui object flushes stderr explicitly (after the change, we could get rid of the explicit flush). One example where it makes a observable difference is mercurial.util.timed(). Without the patch, the time is not immediately shown on Python 3. With the patch, it’s shown immediately on all Python versions and platforms.

tests: generalize common test case code in test-stdio.py

procutil: make stdout line-buffered on Windows if connected to TTY Windows doesn’t support line buffering. Previously, we worked around that by setting the stream unbuffered. Instead, we can use our own line buffering we already use on Python 3.

procutil: split import and reassignment Besides making the code clearer, it will reduce the diff in the next patch.

procutil: move assignments closer to reassignments Doing reassignments is an anti-pattern IMHO, but I see how it makes sense here. When first looking at this code after jumping here with ctags, I missed the fact that stdout was reassigned. To make the code clearer, the assignments should be as close as possible to the reassignments.

procutil: factor out conditional creation of LineBufferedWrapper At the same time, document the logic and generalize it to work on all Python versions.

procutil: define LineBufferedWrapper on all Python versions There’s nothing Python 3-only about LineBufferedWrapper. In the future, we may want to use it on Windows, to work around missing line-buffering support.

tests: add tests for buffering behavior of mercurial.utils.procutil.stdout

cleanup: use slightly more meaningful name for temporary variable Not that it makes a big difference, but using `p` instead of `x` is clearer to me.

cleanup: use any() instead of checking truthiness of temporary list It was not immediately obvious to me, when first seeing this, why a list was created. It needed a second look to understand that the purpose was to check whether the condition is true for any of the parents. Using any() for that is clearer.

chg: suppress OSError in _restoreio() and add some logging (issue6330) According to issue6330, running chg on heavy loaded systems can lead to following error: ``` Traceback (most recent call last): File "path-to-hg/mercurial/commandserver.py", line 650, in _acceptnewconnection self._runworker(conn) File "path-to-hg/mercurial/commandserver.py", line 701, in _runworker prereposetups=[self._reposetup], File "path-to-hg/mercurial/commandserver.py", line 470, in _serverequest sv.cleanup() File "path-to-hg/mercurial/chgserver.py", line 381, in cleanup self._restoreio() File "path-to-hg/mercurial/chgserver.py", line 444, in _restoreio os.dup2(fd, fp.fileno()) OSError: [Errno 16] Device or resource busy ``` [man dup2] indicates that, on Linux, EBUSY comes from a race condition between open() and dup2(). However it's not clear why open() race occurred for newfd=stdin/out/err. We suppress the OSError in _restoreio() since the forked worker process will finish anyway and add some logging. Thanks to Mitchell Plamann for a detailed bug description and Yuya Nishihara for suggesting the fix.

py3: fix crash when server address is 0.0.0.0 (issue6362) `socket.getfqdn()` assumes that the name is passed as `str` on Python 3 and always returns `str` in this case. Mercurial passed `bytes` (but still expected a `str` result), which worked by chance in many cases, except for e.g. b'0.0.0.0', which was returned unchanged, breaking later code. Instead of calling `socket.getfqdn()`, we can also use `self.server_name` from the base `HTTPServer` class, which already stores the FQDN of the locally-bound socket name (see `BaseHTTPServer.py` in the Python 2 stdlib and `http/server.py` in the Python 3 stdlib).

ui: fix Python 2.7 support for ui.timestamp-output Differential Revision: https://phab.mercurial-scm.org/D8675

merge with stable

run-tests: find python binary on Python 3 (issue6361) Return strings from _findprogram as all callers expect unicode strings. Previously the check in _usecorrectpython agains sysexecutable was always false on Python 3. Differential Revision: https://phab.mercurial-scm.org/D8674

tests: ignore possible diagnostics from gpg 2.2 Differential Revision: https://phab.mercurial-scm.org/D8672

Added signature for changeset 0ea9c86fac89

Added tag 5.4.2 for changeset 0ea9c86fac89

convert: handle percent-encoded bytes in file URLs like Subversion 75b59d221aa3 added most of the code that gets removed by this patch. It helped making progress on Python 3, but the reasoning was wrong in many ways. I tried to retract it while it was queued, but it was too late. Back then, I was asssuming that what happened on Python 2 (preserving bytes) is correct and my Python 3 change is a hack. However it turned out that Subversion interprets percent-encoded bytes as UTF-8. Accepting the same format as Subversion is a good idea. Consistency with urlreq.pathname2url() (as described in the removed comment) doesn’t matter because that function is only used for passing paths to urllib. This is not a backwards-incompatible change because before 5c0d5b48e58c, non-ASCII filenames didn’t work at all on Python 2. When the locale encoding is ISO-8859-15, `svn` accepts `file:///tmp/a%E2%82%AC` for `/tmp/a€`. Before this patch, this was the case for this extension on Python 3, but not on Python 2. This patch makes it work like with `svn` on both Python 2 and Python 3.

convert: add docstring on convert.subversion.geturl() The function is unusual for a bytes-handling function in Mercurial because it can’t handle arbitrary bytes. Therefore we should document this fact. Pointed out by Yuya Nishihara while reviewing e3b19004087a.

ui: add option to timestamp status and diagnostic messages Differential Revision: https://phab.mercurial-scm.org/D8640

tests: use path inside test dir This will make the diff for the next patch less noisy.

convert: convert URLs to UTF-8 for Subversion Preamble: for comprehension, note that the `path` of geturl() would better be called `path_or_url` (the argument of the call of getsvn() is called `url`). For HTTP(S) URLs, the changes don’t make a difference, as they are restricted to ASCII. For file URLs, the reasoning is the same as for paths: we have to roundtrip with what Subversion is doing. When the locale encoding is ISO-8859-15, trying to convert a SVN repo `file:///tmp/a€` failed before like this: file:///tmp/a%A4 does not look like a Subversion repository to libsvn version 1.14.0 Decoding the path using the locale encoding can fail. In this case, we have to bail out, as Subversion won’t be able to do anything useful with the path.

convert: correctly convert paths to UTF-8 for Subversion The previous code using encoding.tolocal() only worked by chance in these situations: * The string is ASCII: The fast path was triggered and the string was returned unmodified. * The local encoding is UTF-8: The source and target encoding is the same. * The string is not valid UTF-8 and the native encoding is ISO-8859-1: If the string doesn’t decode using UTF-8, ISO-8859-1 is tried as a fallback. During `hg convert`, the local encoding is always UTF-8. The irony is that in this case, encoding.tolocal() behaves like what someone would expect the reverse function, encoding.fromlocal(), to do. When the locale encoding is ISO-8859-15, trying to convert a SVN repo `/tmp/a€` failed before like this: file:///tmp/a%C2%A4 does not look like a Subversion repository to libsvn version 1.14.0 The correct URL is `file:///tmp/a%E2%82%AC`. Unlike previously (with the ISO-8859-1 fallback), decoding the path using the locale encoding can fail. In this case, we have to bail out, as Subversion won’t be able to do anything useful with the path.

py3: pass URL as str Before the patch, HTTP(S) URLs were never recognized as a Subversion repository on Python 3.

convert: bail out in Subversion source if encountering non-ASCII HTTP(S) URL Before this patch, in the tested case, urllib raised `httplib.InvalidURL: URL can't contain control characters. '/\xff/!svn/ver/0/.svn' (found at least '\xff')`, which resulted in that the URL was never recognized as a Subversion repository. This patch adds a check that bails out if the URL contains non-ASCII characters. The warning is not overly user-friendly, but giving the user something to type into a search engine is definitively better than not explaining why the repository was not recognized. We could support non-ASCII chracters by quoting them before passing them to urllib. However, we would want to be compatible with what the `svn` command does, which converts the URL from the locale encoding to UTF-8, percent-encodes it and sends it to the server. If the locale encoding is not UTF-8, the behavior is IMHO not very intuitive, as the `svn` command may send different (percent-encoded) octets than what was passed on the console. Instead of copying this behavior, we better leave it forbidden.

merge with stable

compat: back out a25343d16ebe (initialize LC_CTYPE locale on all Python ...) As Yuya Nishihara pointed out, setting LC_CTYPE changes the behavior of some str methods on Python 2.

curses: back out d2227d4c9e6b (do not initialize LC_ALL to user settings) The changeset was based on a25343d16ebe, which will be backed out, too. Another fix for the problem will be resubmitted to the stable branch.

test: redirect stderr so warning messages don't change output (issue6237) clone and commit race for the lock, and if commit has to wait more than a second it prints a warning to stderr. Since this is somewhat expected here, silence it. Differential Revision: https://phab.mercurial-scm.org/D8664

locks: expect repo lock, not wlock, when writing to .hg/strip-backup/ There should be no need for a working copy lock when creating (or reading) bundles in `.hg/strip-backup/` since they don't affect the working copy. I noticed this because we have an extension that tries to strip some revisions while holding only a repo lock. I guess we have no such cases in core, which seems a bit surprising. Maybe we always take a wlock at a higher level so the working copy is not updated while the target commit is being stripped. Differential Revision: https://phab.mercurial-scm.org/D8666

graft: leverage cmdutil.check_incompatible_arguments() for --abort/--stop Differential Revision: https://phab.mercurial-scm.org/D8669

run-tests: fix escapes with conditions Before this fix, escapes with conditions in tests failed like this on Python 3: $ $PYTHON -c 'from mercurial.utils.procutil import stdout; stdout.write(b"\xff")' - \xff (no-eol) (esc) (true !) + \xff (no-eol) (esc) The unicode_escape encoding decodes br'\xff' to u'\xff'. To convert the first 256 code points to bytes with the same ordinal, the latin-1 encoding must be used. Escapes without conditions already worked before on Python 3, but not through `el == l` a few lines below the changed line in run-tests.py. I didn’t investigate further.

convert: set LC_CTYPE around calls to Subversion bindings The Subversion bindings require that LC_CTYPE is set. However, we don’t want to set it all the time, as it changes the behavior of str methods on Python 2. The taken approach is hopefully fine-grained enough to not trigger any locale-specfic behavior of the str methods and coarse-grained enough to not clutter the code. Emulating the with-statement behavior in before() and after() should be safe, as after() is always called when before() is called. hgext.convert.hg takes a similar approach.

curses: do not initialize LC_ALL to user settings (issue6358) 701341f57ceb moved the setlocale() call to right before curses was used. This didn’t fully solve the problem it was supposed to solve (locale-dependent functions, like date formatting/parsing and str methods on Python 2), but only postponed it. Initializing LC_CTYPE seems to be sufficient for curses to work correctly. Therefore LC_CTYPE is set while curses is used and reset afterwards. Some locale-dependent str methods might behave differently on Python 2 while curses is used, but that shouldn’d be a problem.

graft: leverage cmdutil.check_incompatible_arguments() for --no-commit Differential Revision: https://phab.mercurial-scm.org/D8668

graft: leverage cmdutil.check_at_most_one_arg() for --abort/--stop/--continue Differential Revision: https://phab.mercurial-scm.org/D8667

version: sort extensions by name in verbose mode External extensions can be assigned any name, but presumably most enabled extensions will be internal ones and having them sorted makes it easier to find specific ones if the list is long. The lists in `hg help extensions` are already sorted. Differential Revision: https://phab.mercurial-scm.org/D8671

crecord: stop trying to import wcurses The original import of crecord in 2008 already said "I have no idea if wcurses works with crecord...". The last reference to a Python package called wcurses is https://web.archive.org/web/20101025073658/http://adamv.com/dev/python/curses/. However, the Python package from there is called "curses" and not "wcurses". I didn’t find any evidence that it ever worked.

debian: support building a single deb for multiple py3 versions Around transitions from one python minor version to another (such as 3.7 to 3.8), the current packaging can be slightly problematic - it produces a `control` file that requires that the version of `python3` that's installed be exactly the one that was used on the build machine for the `mercurial` package, by containing a line like: Depends: sensible-utils, libc6 (>= 2.14), python3 (<< 3.8), python3 (>= 3.7~), python3:any (>= 3.5~) This is because it "knows" we only built for v3.7, which is the current default on my system. By building the native components for multiple versions, we can make it produce a line like this, which is compatible with 3.7 AND 3.8: Depends: sensible-utils, libc6 (>= 2.14), python3 (<< 3.9), python3 (>= 3.7~), python3:any (>= 3.5~) This isn't *normally* required, so I'm not making it the default. For those that receive their python3 and mercurial packages from their distro, and/or don't have to worry about a situation where the team that manages the python3 installation isn't the same as the team that manages the mercurial installation, this is probably not necessary. I chose the names `DEB_HG_*` because `DEB_*` is passed through `debuild` automatically (otherwise we'd have to explicitly allow the options through, which is a nuisance), and the `HG` part is to make it clear that this isn't a "standard" debian option that other packages might respect. Test Plan: 1. "nothing changed": - built a deb without these changes - built a deb with these changes but everything at the default - used diffoscope to compare, all differences were due to timestamps 2. "explicit is the same as implicit" (single version) - built a deb with everything at the default - built a deb with DEB_HG_PYTHON_VERSIONS=3.7 - used diffoscope to compare, all differences were due to timestamps 3. "explicit is the same as implicit" (multi version) - built a deb with DEB_HG_MULTI_VERSION=1 - built a deb with DEB_HG_PYTHON_VERSIONS=3.7 - used diffoscope to compare, all differences were due to timestamps 4. (single version, 3.7) doesn't work with python3.8 - `/usr/bin/python3.7 /usr/bin/hg debuginstall` works - `/usr/bin/python3.8 /usr/bin/hg debuginstall` crashes 5. (multi version, 3.7 + 3.8) - `/usr/bin/python3.7 /usr/bin/hg debuginstall` works - `/usr/bin/python3.8 /usr/bin/hg debuginstall` works Differential Revision: https://phab.mercurial-scm.org/D8642

merge with stable

hgweb: encode WSGI environment like OS environment Previously, the WSGI environment keys and values were encoded using latin-1. This resulted in a crash if a WSGI environment key or value could not be encoded using latin-1. On Unix, the OS environment is byte-based. Therefore we should do the reverse of what Python does for os.environ. On Windows, there’s no native byte-based OS environment. Therefore we should do the same as what mercurial.encoding does with the OS environment.

hgweb: deduplicate code A following patch will change the way keys and values are encoded. To reduce the diff, I’ve split off the uninteresting part.

curses: do not initialize LC_ALL to user settings (issue6358) 701341f57ceb moved the setlocale() call to right before curses was used. This didn’t fully solve the problem it was supposed to solve (locale-dependent functions, like date formatting/parsing), but only postponed it. Initializing LC_CTYPE seems to be sufficient for curses to work correctly. Luckily this is already done at interpreter startup on modern Python versions and, since recently, by Mercurial in the pycompat module in all other cases.

compat: initialize LC_CTYPE locale on all Python versions and platforms Previously, the LC_CTYPE locale was not initialized according to user settings on all Python versions (e.g. never on Python 2) and platforms (e.g. not on some Python < 3.8 on Windows). This broke e.g. non-ASCII filenames passed to the Subversion bindings on Python 2, resulting in error messages like "file:///tmp/a%C3%A4 does not look like a Subversion repository to libsvn version 1.14.0". The following command could be used to test this functionality. Adding it to the test suite would be pointless, as the locale is always set to "C" during test runs. @command(b'check_initial_codeset', norepo=True) def check_initial_codeset(ui): codeset1 = locale.nl_langinfo(locale.CODESET) locale.setlocale(locale.LC_ALL, '') codeset2 = locale.nl_langinfo(locale.CODESET) assert codeset1 == codeset2

merge with stable

merge: don't grab wlock when merging in memory I noticed this because we have an internal extension that does an in-memory rebase while holding only a repo lock, which resulted in a developer warning about the working copy lock being taken after the repo lock. Differential Revision: https://phab.mercurial-scm.org/D8665

pycompat: use os.fsencode() to re-encode sys.argv Historically, the previous code made sense, as Py_EncodeLocale() and fs.fsencode() could possibly use different encodings. However, this is not the case anymore for Python 3.2, which uses the locale encoding as the filesystem encoding (this is not true for later Python versions, but see below). See https://vstinner.github.io/painful-history-python-filesystem-encoding.html for a source and more background information. Using os.fsencode() is safer, as the documentation for sys.argv says that it can be used to get the original bytes. When doing further changes, the Python developers will take care that this continues to work. One concrete case where os.fsencode() is more correct is when enabling Python's UTF-8 mode. Py_DecodeLocale() will use UTF-8 in this case. Our previous code would have encoded it using the locale encoding (which might be different), whereas os.fsencode() will encode it with UTF-8. Since we don’t claim to support the UTF-8 mode, this is not really a bug and the patch can go to the default branch. It might be a good idea to not commit this to the stable branch, as it could in theory introduce regressions.

merge with stable

perf: make `hg perfwrite` more flexible The more flexible command was used recently while finding a solution for a buffering bug (eventually fixed in f9734b2d59cc (the changeset description uses a different benchmark)). In comparison to the previous version, the new version is much more flexible. While using it, the focus was on testing small writes. For this reason, by default it calls ui.write() 100 times with a single byte plus one newline byte, for 100 lines. To get the previous behavior, run `hg perfwrite --nlines=100000 --nitems=1 --item='Testing write performance' --batch-line`.

chg: fix typo

copies: implement __repr__ on branch_copies for debugging Differential Revision: https://phab.mercurial-scm.org/D8650

phases: remove useless lookup of repo[rev].rev() in _retractboundary changectx object is no longer needed thanks to a54ee130210a.

ui: replace `self._ferr` with identical `dest` Originally, it was part of a larger change that was abandoned. IMHO it makes the code slightly cleaner and saves one attribute access, so I decided to send it anyway instead of throwing it away.

absorb: make it clear what happens when no input Differential Revision: https://phab.mercurial-scm.org/D8643

tests: add hghave rule 'setprocname' to check if osutil.setprocname and use it setprocname is not present when we build a pure version. This leads to output changes in test-chg.t This should make test suite green on Python 2 pure build with chg. Differential Revision: https://phab.mercurial-scm.org/D8638

util: flush stderr explicitly after using warnings.warn() Due to some unknown reasons, when using chg with python3, the warnings.warn() output is not flushed. Fixes test-devel-warnings.t on py3 with chg.

phases: improve performance of _retractboundary The old version repeatedly converts nodes to revisions, which is a moderately expensive operation. Mapping all new changes once to revisions and back at the end reduces the time spend in _retractboundary during the unbundling of NetBSD's src from 67s to 17s. Differential Revision: https://phab.mercurial-scm.org/D8641

tests: use proctutil.stdout.write() instead of print() in test-extension.t I was debugging this test failure on python3 + chg. I get the following hunk as test failure: ``` @@ -206,6 +206,18 @@ Check normal command's load order of ext 4) bar uipopulate 5) foo reposetup 5) bar reposetup + 4) foo uipopulate (chg !) + 4) bar uipopulate (chg !) + 4) foo uipopulate (chg !) + 4) bar uipopulate (chg !) + 4) foo uipopulate (chg !) + 4) bar uipopulate (chg !) + 4) foo uipopulate (chg !) + 4) bar uipopulate (chg !) + 4) foo uipopulate (chg !) + 4) bar uipopulate (chg !) + 5) foo reposetup (chg !) + 5) bar reposetup (chg !) 0:c24b9ac61126 ``` After hours of debugging and head scracthing, I figured out that something is wrong with output flushing. I initially switched the print() statements to ui.warn() but thanks to Yuya who suggested using procutil.stdout.write() instead.

fuzz: tell manifest fuzzer about longer node hashes Differential Revision: https://phab.mercurial-scm.org/D8374

absorb: preserve changesets which were already empty Most commands in Mercurial (commit, rebase, absorb itself) don’t create empty changesets or drop them if they become empty. If there’s a changeset that’s empty, it must be a deliberate choice of the user. At least it shouldn’t be absorb’s responsibility to prune them. The fact that changesets that became empty during absorb are pruned, is unaffected by this. This case was found while writing patches which make it possible to configure absorb and rebase to not drop empty changesets. Even without having such config set, I think it’s valuable to preserve changesets which were already empty.

absorb: preserve branch-closing changesets even if empty This makes the behavior consistent with 'hg commit', which allows to create otherwise empty changesets if they close the branch. A lost branch closure can inadvertently re-open a branch, so it should be preserved.

absorb: preserve branch-changing changesets even if empty This makes the behavior consistent with 'hg commit', which allows to create otherwise empty changesets if the branch changes compared to the parent. A branch change can denote important information, so it should be preserved.

rhg: add Command trait for subcommands implemented by rhg Normalizes the interface of the cli's commands Differential Revision: https://phab.mercurial-scm.org/D8611 Differential Revision: https://phab.mercurial-scm.org/D8648

rhg: add rhg crate The goal of rhg is to speedup some of hg's commands when possible by bypassing python entirely for the time being. It is by no means a replacement for hg as it will not support extentions or configuration and implement only a subset of hg's commands and options. Only use rhg if you understand what the tradeoffs are. Differential Revision: https://phab.mercurial-scm.org/D8610

hg-core: add FindRoot operation to find repository root path Differential Revision: https://phab.mercurial-scm.org/D8609

share: provide a more useful text for hg help Differential Revision: https://phab.mercurial-scm.org/D8651

procutil: make recent fix for zombies compatible with py2 The fix in ed684a82e29b (procutil: always waiting on child processes to prevent zombies with 'hg serve', 2020-05-07) works only on Python 3 because it passes a `daemon` argument to `threading.Thread()`. Python 2 requires you to assign to the `.daemon` property instead. Python 3 also seems to support that, so this patch fixes the code by unconditionally using the old form. Differential Revision: https://phab.mercurial-scm.org/D8657

pycompat: fix crash when default locale is unknown Instead, fall back to the filesystem encoding if the default locale is unknown.

help: document meaning of '%' in graphlog output I added the feature in 14d0e89520a2 (graphlog: use '%' for other context in merge conflict, 2020-01-28), but I didn't think to look for documentation until today (because an internal user asked about it). Differential Revision: https://phab.mercurial-scm.org/D8649

py3: fix broken man page generation, it was generating `(default: NUL*)` `bytes(default)` was producing things like `(default: \x00)` when handed non-bytes values such as `1`, `10`, or `True`. The man page generation would apparently ignore these bytes and produce man pages that had the string `(default: )`. Test Plan: - Ran `cd doc; python3 gendoc.py "hg.1.gendoc"` and grepped for bad output - Ran `make deb`, extracted the deb, manually inspected `hg.1` file. Differential Revision: https://phab.mercurial-scm.org/D8639

hg-core: add Operation interface for high-level hg operations A distinction is made between operations and commands. An operation is a high-level function of mercurial whereas a command is what is exposed by the cli. A single command can use several operations to achieve its goal. Differential Revision: https://phab.mercurial-scm.org/D8608

rust: do a clippy pass This is the result of running `cargo clippy` on hg-core/hg-cpython and fixing the lints that do not require too much code churn (and would warrant a separate commit/complete refactor) and only come from our code (a lot of warnings in hg-cpython come from `rust-cpython`). Most of those were good lints, two of them was the linter not being smart enough (or compiler to get up to `clippy`'s level depending on how you see it). Maybe in the future we could have `clippy` be part of the CI. Differential Revision: https://phab.mercurial-scm.org/D8635

py3: fix comparison between int and None If stop is None, the condition was always false on Python 2, as None compares smaller than ints. Therefore we make the condition false if stop is None.

py3: pass regex as bytes

py3: avoid using %r format on bytes Before the patch, the 'b' prefix appeared in the formatted string. Wrapping the bytes as pycompat.bytestr solves this problem. Eventually, I think that we should move away from using %r (like 975e517451a6 and 4d6019c0e0ef did), but that would change output of non-ASCII bytes on Python 2, so we can’t do it on the stable branch. Also, many places continue to use %r, so it would be a good idea to do the change all at once.

py3: use `%d` for int in % formatting On Python 3, `%s` is an alias to `%b`, which requires that the object implements `__bytes__()`, which is not the case for `int`.

py3: pass native string to urlreq.url2pathname() Of course, I’m not happy with the warning, but it’s better than crashing. Solving the problem properly is hard, and non-UTF-8 percent-encoded bytes in file URLs seem rare enough to block solving that all file URLs (even if not SVN-specific) will cause a crash.

py3: suppress DeprecationWarning about deprecated base64 module aliases base64.encodestring() / base64.decodestring() were renamed to base64.encodebytes() / base64.decodebytes() in Python 3. The old names still worked, but raised a DeprecationWarning.

py3: use `pycompat.ziplist()`

py3: use `%d` for int in % formatting On Python 3, `%s` is an alias to `%b`, which requires that the object implements `__bytes__()`, which is not the case for `int`.

py3: fix bytes iteration