git: implement basic bookmark activation This is very limited, but it allows 'hg update foo' when already on foo. The caching is based on bmstore's caching.

git: implement a basic checkconflict bookmark store method It is heavily based on bmstore's own checkconflict.

git: abort when attempting to set a branch Given the mapping we use (namely, a git head is a bookmark), it is better to error out with a hint.

git: remove obsolete todo item The changes in 02c47b74366c cleaned up the requirement check.

tests: don't run test-update-atomic.t on chg I am unable to find a good way to make `showwrites` extension in it to work with chg. Also putting the use of showwrites inside `if no-chg` will defeat the purpose of test, so I just made the test no-op on chg.

tests: don't run couple of tests related to extensions loading with chg The couple of files test extensions loading and debugging that. It sets `devel.debug.extensions` to True to do that. Either we have to restart chg if this config is set or just don't run these tests on chg. I tried the first way by adding the config option to chgserver.py list of config subsections but that does not seem to work.

tests: conditionalize test-phases.t output for chg IIUC chg loads the ProgrammingError class which leads to it directly referencing it in error output. This makes the test pass on chg.

chg: be stricter about checking invocation of `serve` command Few tests run serve command in form of `hg -R <repo> serve` which leads to chg thinking that it's not a serve command and failing tests. We become more stricter in checking for the serve command. This fixes test-server-view.t, test-remote-hidden.t, test-remotefilelog-http.t, test-phases-exchange.t, test-wireproto-content-redirects.t with chg.

chgserver: add merge-tools to sensitive config items Because this can change whether the ui is gui or not. This fixes test-extdiff.t with chg.

run-tests: add --chg-debug flag to show chg debug output This has helped me a lot in debugging chg failures in tests.

tests: update test-ssh.t output with --chg The output change was caused by d7304434390f5efca405744fa12a6585edae3d83.

tests: update test-devel-warnings.t output with chg The output change was caused by dc9901558e3c6a78bad3f6594b3888f95104c443.

chgserver: add fastannotate config section to sensitive list Depending on the config value of `fastannotate.modes`, the fastannotate extension can do different things in uisetup. Depending on value of `fastannotate.server`, it can register new wireprotocol capabilities. This fixes test-fastannotate-hg.t, test-fastannotate-protocol.t and test-fastannotate.t with chg.

histedit: add missing b prefix to a string If i18n is disabled (such as via HGPLAIN=1), `_()` doesn't convert from str to bytes, so this raises a TypeError on py3. Differential Revision: https://phab.mercurial-scm.org/D8354

phabricator: account for `basectx != ctx` when calculating renames No functional changes here because the two are the currently same, but they won't be with a `--fold` option. Differential Revision: https://phab.mercurial-scm.org/D8307

phabricator: add basectx arguments to file related `phabsend` utilities This is in support of a future `--fold` option, that allows rolling up several commits into a single review with a diff from the start to the end of the range. There are no functional changes yet- the original `ctx` is also passed as the new `basectx`, which represents the first commit in the review range (similar to `qbase` in MQ parlance). Other functions will need the range of commits, but these deal with status or the diffs, so they only need the end points. Differential Revision: https://phab.mercurial-scm.org/D8306

phabricator: eliminate a couple of duplicate filectx lookups Differential Revision: https://phab.mercurial-scm.org/D8305

tests: update test-debugcommands.t stack trace checks for python3.9 Python 3.9 prints a complete filepath in more cases, so we need to handle that in our test output. Since we don't really care *that* much about the specific path formatting here, just use globbing. Differential Revision: https://phab.mercurial-scm.org/D8329

tests: update test-archive.t expectations for python3.9 changes Sigh. Differential Revision: https://phab.mercurial-scm.org/D8328

setup: relax -Werror for declaration-after-statement on Python 3.9 It turns out Python 3.9 introduces such declarations in the headers, eg cpython/abstract.h:189:5: error: ISO C90 forbids mixed declarations and code [-Werror=declaration-after-statement] so we have to be more relaxed when compiling for 3.9. Differential Revision: https://phab.mercurial-scm.org/D8327

py3: require values in changelog extras to be bytes I don't know what happened here because b436059c1cca (py3: use pycompat.bytestr() on extra values because it can be int, 2019-02-05) came about b44a47214122 (py3: use string for "close" value in commit extras, 2018-02-11). Whatever happened, we shouldn't need to convert the values to bytes now. It's better to not convert because that might cover up bugs where someone sets a unicode value in the extras and that works until the unicode value happens to contain non-ascii (at which point it will fail because `bytestr()` expects its argument to be ascii if it's unicode). Differential Revision: https://phab.mercurial-scm.org/D8332

py3: make setup.py's hgcommand() consistently return bytes Before this patch, it returned unicode when the command failed. That made e.g. `make local PYTHON=python3` fail on an obsolete commit. Differential Revision: https://phab.mercurial-scm.org/D8331

pvec: drop an unused `from __future__ import division` This module only uses the `//` operator (for integer division). Differential Revision: https://phab.mercurial-scm.org/D8326

py3: use integer division in histedit Histedit uses the `/` operator, which does type conversion to float in Python 3 instead of integer division likeon Python 2. Let's preserve the Python 2 behavior by importing and using the `//` operator. Differential Revision: https://phab.mercurial-scm.org/D8324