worker: adapt _blockingreader to work around a python3.8.[0-1] bug (issue6444) Python 3.8.0 is the latest I can load on Ubuntu 18.04, and I regularly hit the TypeError because this function is missing. While it can be avoided by disabling worker usage via config option, that's a bit obscure. I'm limiting the function definition to the narrow range of affected pythons because there were other bugs in this area that were worked around, that I don't fully understand. See the bug report for discussions on why the narrow range, and related commits working around other bugs. Differential Revision: https://phab.mercurial-scm.org/D12627

doc: use an absolute path in sys.path The idea and rationale is similar to https://phab.mercurial-scm.org/D12599 (landed as 1b6e381521c5). Differential Revision: https://phab.mercurial-scm.org/D12622

check-py3-compat: use an absolute path in sys.path The idea and rationale is similar to https://phab.mercurial-scm.org/D12599 (landed as 1b6e381521c5). Differential Revision: https://phab.mercurial-scm.org/D12621

rhg: align the dirstate v2 writing algorithm with python Use the same algorithm of file append as python does, where we do a manual seek instead of relying on O_APPEND. (see the reasons in the inline comment)

test-dirstate: actually test the append code path in dirstate v2 Apparently it's not sufficient to modify a file to force the dirstate write-out, so the append code path was untested. By removing a file instead of changing we're forcing append to happen.

ci: do not trigger phabricator for merge-request The fast the phabricator steps has a `rules` entry makes it selected for the special `merge_requests` pipelines. The other ones behave as default and are not selected tot the mrege_request pipelines. This result in a second pipeline to be created, with only the phabricator pipeline in it. Which usually succeed fast (since there is nothing to do). This is harmful as this create a false sense of "the series is passing" and Gitlab will use this simplistic pipeline for validation. By explicitly preventing the pipeline to be created in the merge-request case, we prevent this situation to happens Note that the job will be dropped (alonside phabricator) in the next two weeks anyway.

amend: stop specifying matcher, get all copies in wctx When we're recreating the commit that we'll be committing, we don't want to filter our copy information based on just the *new* [versions of the] files we're amending. The test has an example of this case, but for clarity, the situation is: ``` $ hg cp src dst && hg commit <do some work> $ hg amend some_unrelated_file.txt $ hg status --copies A dst A some_unrelated_file.txt ``` What *should* happen is that `dst` should remain marked as a copy of `src`, but this did not previously happen. `matcher` here only includes the files that were specified on the commandline, so it only gets the copy information (if any, in this example there's not) for `some_unrelated_file.txt`. When it goes to apply the memctx to actually create the commit, the file copy information is incomplete and loses the information for the files that shouldn't have been affected at all by the amend. Differential Revision: https://phab.mercurial-scm.org/D12625

amend: add test showing poor behavior when copies are involved Differential Revision: https://phab.mercurial-scm.org/D12624

censor: fix [hg update] away from a revision with censored files Differential Revision: https://phab.mercurial-scm.org/D12604

censor: demonstrate a bug Differential Revision: https://phab.mercurial-scm.org/D12584