help: document weird behavior of uisetup() While refactoring ui.log() API, it was really annoying that uisetup() is actually an extsetup() the phase 1. Let's document that. I'm planning to add another uisetup() which is called per ui instance, though I can't think of a good name for it.

help: merge section about uisetup() and extsetup() They are technically the same callback, called only once per process. The section name "ui setup" is confusing, so shouldn't be used.

help: add internals.extensions topic I think it's better to include the API overview in core as we now have the internals section in our help system. Retrieved from the wiki, and formatted as reST. Several wiki links are removed since they are invalid in the help. The sections about example extension are removed at all as they seemed too verbose. https://www.mercurial-scm.org/wiki/WritingExtensions

commandserver: send raw progress information to message channel This is pretty basic implementation to support GUI progress bar.

commandserver: make getpass() request distinct from normal prompt Otherwise, GUI clients would have to parse the prompt text.

commandserver: attach prompt default and choices to message These attributes are important to provide a GUI prompt to user.

test-commandserver: clean up quoting and location of dbgui extension This helps embedding '$' in the script.

ui: extract helpers to write message with type or label This provides a 'type' attribute to command-server clients, which seems more solid than relying on 'ui.<type>' labels. In future patches, type='progress' will be added to send raw progress information.

commandserver: add experimental option to use separate message channel This is loosely based on the idea of the TortoiseHg's pipeui extension, which attaches ui.label to message text so the command-server client can capture prompt text, for example. https://bitbucket.org/tortoisehg/thg/src/4.7.2/tortoisehg/util/pipeui.py I was thinking that this functionality could be generalized to templating, but changed mind as doing template stuff would be unnecessarily complex. It's merely a status message, a simple serialization option should suffice. Since this slightly changes the command-server protocol, it's gated by a config knob. If the config is enabled, and if it's supported by the server, "message-encoding: <name>" is advertised so the client can stop parsing 'o'/'e' channel data and read encoded messages from the 'm' channel. As we might add new message encodings in future releases, client can specify a list of encoding names in preferred order. This patch includes 'cbor' encoding as example. Perhaps, 'json' should be supported as well.

commandserver: fix reference before assignment error in pipeservice cleanup Spotted by the next patch.

dispatch: pass around ui.fmsg channel This will be set by the command server. See the next patch.

test-subrepo: document why share magically works even if subrepos are missing I was confused how it's working while reviewing fb490d798be0, "share: reload repo after adjusting it in postshare()."

packaging: add Fedora 29 target Differential Revision: https://phab.mercurial-scm.org/D5254

store: pass in decoded filename to narrow matcher

test-narrow-clone-stream: include no usefncache case which is broken Since 9aeb9e2d28a7, encoded filenames are filtered by the narrow matcher, which is clearly wrong.

test-narrow-clone-stream: include uppercase letter in filename This makes encoded filenames differ from the original names.

phase: use the `phases.cmdphasenames` constant to walk available command flags This reverts 1ea6772fb415.

phases: add a list of names usable by the phase command This is useful in TortoiseHg for example, which has until recently just added all names in the `phasenames` list to the context menu that changes the phase. The ones not supported by the command would just error out.

transaction: display data about why the transaction failed to rollback We saw more of these a while back. Having more data available would be nice.

merge with stable

remotefilelog: avoid accessing repo instance after dispatch Upstream commit c5e6c1ba1c79 (hg: don't reuse repo instance after unshare(), 2018-09-12) poisoned the repo instance after unshare(). That made `hg unshare` fail with remotefilelog because we tried to close the fileserverclient after dispatch by accessing it via the repo. This patch fixes that by storing the reference to the fileserverclient at the beginning of dispatch. An analogous patch was sent for remotefilelog version in FB's hg-experimental as D5246. Differential Revision: https://phab.mercurial-scm.org/D5253

share: avoid a now-unnecessary reload of the repo hg.share() now returns an already-reloaded repo, so let's just use that. (This would have failed test-subrepo-recursion.t without the previous patch.) Differential Revision: https://phab.mercurial-scm.org/D5252

share: reload repo after adjusting it in postshare() When sharing a repo that's using remotefilelog, the update that happens at the end of the `hg share` call does not see the remote repo path that's copied in hg.postshare(). This patch reloads the repo after hg.postshare() to address that. This changes a subrepo test case. Note that `hg share -U; hg co tip` worked there before, so I don't see see why `hg share` should fail. I also don't know what a "locally referenced subrepo". So maybe this is fixing a bug? Hopefully it's not breaking something someone actually cares about at least. Maybe someone who knows and cares about subrepos can review this. Differential Revision: https://phab.mercurial-scm.org/D5251

tests: don't load strip extension via mq extension for remotefilelog tests The proper way to get the `hg strip` command has been via the "strip" extension since 2013. Differential Revision: https://phab.mercurial-scm.org/D5250

remotefilelog: remove unused configs for {data,history}pack version Differential Revision: https://phab.mercurial-scm.org/D5249

tests: remove obsolete PYTHONPATH override from remotefilelog tests They were added in https://bitbucket.org/facebook/hg-experimental/commits/fdcad37a6a68cfbaf5920f3eeaa0cc9cae42bd26, which says this: When remotefilelog moved from its own repo, the tests needed to be updated to adjust the PYTHONPATH to ensure the in-repo remotefilelog was loaded instead of the system one. This meant any local runs of remotefilelog tests would've been using the system remotefilelog unless the user had manually set the PYTHONPATH themselves. That doesn't seem relevant with remotefilelog in core. Differential Revision: https://phab.mercurial-scm.org/D5248

tests: drop obsolete "hginit" alias in remotefilelog tests Differential Revision: https://phab.mercurial-scm.org/D5247

fix: add extra field to fixed revisions to avoid creating obsolescence cycles The extra field prevents sequential invocations of fix from producing the same hash twice. Previously, this could cause problems because it would create an obsolescence cycle instead of the expected new successor. This change also adds an explicit check for whether a new revision should be committed. Until now, the code relied on memctx.commit() to quietly do nothing if the node already exists. Because of the new extra field, this no longer covers the case where we don't want to replace an unchanged node. Differential Revision: https://phab.mercurial-scm.org/D5245

cleanup: use revision numbers instead of hashes in test output This allows changes to the hashes produced by fix to not needlessly modify this area of the test. Differential Revision: https://phab.mercurial-scm.org/D5244

tests: make the commands.resolve.confirm tests not pollute the test-wide hgrc I want to add tests after these tests that create a new repo and use it, and was confused for a bit as to why they were seeing different behavior than I expected. Differential Revision: https://phab.mercurial-scm.org/D5242

tests: fix a couple typos in test-resolve.t comments and add a comment Differential Revision: https://phab.mercurial-scm.org/D5241

fix: add suboption for configuring execution order of tools This could be accomplished by using wrapper scripts, but that would diminish the usefulness of the incremental formatting logic. Configuring execution order along with other things in the hgrc is probably more convenient anyway. This change highlights some awkwardness with suboptions and default values, which should be addressed separately. Differential Revision: https://phab.mercurial-scm.org/D5237

tests: fix up some import statements caught by Python 3 I'm curious how the import checker manages to be so much more pedantic in Python 3, but not enough to bother exploring. Differential Revision: https://phab.mercurial-scm.org/D5240

tests: replace `tac` reimplementation by `sort -r` `sort -r` is better code "formatter" than `tac` since it's stable. It's also portable so we don't need to reimplement it in Python. Differential Revision: https://phab.mercurial-scm.org/D5239

tests: work around `tac` not being portable Introduce a tac.py helper and use it. Sigh. Differential Revision: https://phab.mercurial-scm.org/D5238

revlog: give formatting to clang-format This has two lines that are poorly formatted, both right after PyObject_HEAD macros. It's possible that in the future there will be a feature to tell clang-format that a token includes an end-of-line character (in this case the ;), but for now I'm willing to live with two poorly-formatted lines in a struct definition in exchange for not thinking about how this file is formatted. Differential Revision: https://phab.mercurial-scm.org/D5234

revlog: add blank line in comment to help clang-format Differential Revision: https://phab.mercurial-scm.org/D5233

revlog: add a comment to help clang-format produce less-awful results Differential Revision: https://phab.mercurial-scm.org/D5232

py3: ratchet caught two more passing tests Differential Revision: https://phab.mercurial-scm.org/D5236

perf: add a lazydeltabase option to perfrevlogwrite The option controls if we'll test the provided delta first. This is the current default behavior for unbundle.

perf: add `storage` as possible source for perfrevlogwrite This source will use the stored delta.

perf: add `parent-smallest` as possible source for perfrevlogwrite This source will use the smallest of the possible diff against parent.

perf: add `parent-2` as possible source for perfrevlogwrite This source will use a diff against p2 if it exists and fall back to p1 otherwise.

perf: add `parent-1` as possible source for perfrevlogwrite This source will use a diff against p1 in all case.

perf: add the notion of "source" to perfrevlogwrite We want to test performance associated witch various way to add a new revision. They will be specified using this new argument.

perf: only display the total time for perfrevlogwrite if quiet This provide a simple way to get an overview of the total performance.

perf: offer full details in perfrevlogwrite This will be useful for people who want to study the timing pattern more closely.

perf: introduce a perfrevlogwrite command The command record times taken by adding many revisions to a revlog. Timing each addition, individually. The "added revision" are recreations of the original ones. To time each addition individually, we have to handle the timing and the reporting ourselves. This command is introduced to track the impact of sparse-revlog format on delta computations at initial storage time. It starts with the full text, a situation similar to the "commit". Additions from an existing delta are better timed with bundles. The complaints from `check-perf-code.py` are not relevant. We are accessing and "revlog" opener, not a repository opener.

tests: fix config knob in test-narrow-clone-stream.t Two patches landed in parallel and had a semantic conflict. This resolves the mess and leaves us with passing tests. Differential Revision: https://phab.mercurial-scm.org/D5231

remotefilelog: fix various whitespace issues in docstring Differential Revision: https://phab.mercurial-scm.org/D5230

ui: add config knob to redirect status messages to stderr (API) This option can be used to isolate structured output from status messages. For now, "stdio" (stdout/err pair) and "stderr" are supported. In future patches, I'll add the "channel" option which will send status messages to a separate command-server channel with some metadata attached, maybe in CBOR encoding. This is a part of the generic templating plan: https://www.mercurial-scm.org/wiki/GenericTemplatingPlan#Sanity_check_output .. api:: Status messages may be sent to a dedicated stream depending on configuration. Don't use ``ui.status()``, etc. as a shorthand for conditional writes. Use ``ui.write()`` for data output.

ui: hide fin/fout/ferr attributes behind @property functions This allows keeping references to fout/ferr/fin which are updated when these properties are changed. See the next patch.

ui: label prompt and echo messages I'm going to add a dedicated command-server channel for status messages, which carries metadata alongside a message text. 'ui.*' label provides a hint how message text should be processed.

ui: add inner function to select write destination I'm going to add a config knob to redirect any status messages to stderr. This function helps to switch underlying file objects. # no-check-commit because of existing write_err() function

ui: remove _write() and _write_err() functions

ui: move pre/post processes from low-level write()s to _writenobuf() This helps adding a dedicated stream for status/error messages. I don't want to add _write*() function per stream.

ui: pass in file object to _writenobuf() See the subsequent patches for why. The "if" block in _writenobuf() will be removed soon.

perf: fix perfrevlogrevisions --reverse Currently, 'endrev' equals `len(revlog)`, a revision that does not exist. When asking for the reverse order, the arguments passed to xrange are `xrange(len(revlog), startrev)` which then crash. We need to offset 'endrev' by one so we don't crash anymore. Also, we offset 'startrev' to ensure we get the same number of revisions with and without the `--reverse` option. Differential Revision: https://phab.mercurial-scm.org/D5228

procutil: import concerns about creationflags on Windows from D1701 I don't have the need anymore for the change in D1701 nor the time to investigate the changes on all supported Windows platforms. I import the stuff I learned on D1701 in the `runbgcommand` so the next people working on it can starts from there. Differential Revision: https://phab.mercurial-scm.org/D5229

localrepo: extract loading of hgrc files to standalone function Various 3rd party extensions supplement where per-repo config data lives. Looking at their sources, they resort to unorthodox means to inject the config data. And the way they do it is susceptible to corner cases. e.g. not processing automatic extension loads, not reacting to new or disabled extensions in configs, etc. This commit extracts the core logic of loading hgrc files into a standalone function so there is a clear function that can be monkeypatched to inject per-repo config data at repository open time. Differential Revision: https://phab.mercurial-scm.org/D5221