tests: conditonalize a difference in test-merge-tools.t on Windows

statprof: clean up unicode/bytes a little I'm not really sure how this worked before, but something perturbed it and what I've got in this change I believe is a little tidier. This fixes test-profile.t on Python 3. Differential Revision: https://phab.mercurial-scm.org/D5210

statprof: add a couple of asserts to avoid storing unicodes I don't feel strongly about this change, so it'd be fine to drop it during review, but it was _extremely_ helpful in drafting the next change. Differential Revision: https://phab.mercurial-scm.org/D5209

tests: add some helpful `|| cat` bits to test-profile.t This way if the hg invocation crashes, you get to see a stacktrace without having to edit the test. Differential Revision: https://phab.mercurial-scm.org/D5208

tests: skip wireproto clientreactor tests on Python 3.6.0-3.6.3 inclusive See comment next to the if statement for sad details. Differential Revision: https://phab.mercurial-scm.org/D5207

contrib: tweak import-checker to always use bytes for module names We could go the other route and make embedded() return this as a bytes, but then it would be harder to portably doctest, so I prefer this option. Differential Revision: https://phab.mercurial-scm.org/D5206

contrib: fix import-checker to not b'' module names on Python 3 Caught by the doctests. Differential Revision: https://phab.mercurial-scm.org/D5205

tests: add a critical flush() to run-tests.py to make output stable on py3 Differential Revision: https://phab.mercurial-scm.org/D5204

merge-tools: when calling external merge tool, describe the resolve inputs It is a common complaint that a user will be running some operation (histedit, rebase, evolve, etc.), get into a merge-conflict situation, and not understand what they are seeing - it is possible that the merge tool is configured to display the hash, but it's difficult for most merge tools to display a good snippet of the description. In the worst case, configuring this template will lead to output that is immediately covered by a terminal application, maybe the user can hit ctrl-z to see it. In the common case, the output will be in a terminal window and a GUI program will start, and it should be possible to view both the terminal and the GUI program at the same time. Differential Revision: https://phab.mercurial-scm.org/D5094

templatekw: deprecate p1rev/p2rev/p1node/p2node in favor of p1/p2

templatekw: add p1/p2 keywords which switches the current ctx This is just an example of mappingdict. I have no idea what should be displayed as {p1|json}. Currently it is an empty dict since {'ctx'} isn't displayable, which is clearly useless and should be changed later.

templater: add wrapper for a single template mapping This can be used to nest template mappings without inserting a sequence-like layer. See the next patch for example.

templatekw: extract internal "{rev}:{node|formatnode}" template to constant This will be used later.

tweakdefaults: remove commands.resolve.mark-check=abort, it is too broken See issue6020 for the current case. I don't want to continue attempting to fix this on the stable branch, so I'm removing from tweakdefaults and will send fixes meant for the default branch and 4.9. Differential Revision: https://phab.mercurial-scm.org/D5225

resolve: when resolve.mark-check=abort, downgrade to warning if pats specified Previously, with --config resolve.mark-check=abort, running `hg resolve -m foo` would abort and emit a message saying to use --all. This command does not work, though: `hg resolve -m foo --all`, and it's really weird for --all to be the "--force" flag. My original goal with the option was to make it so that `hg resolve -m` (no filename arguments) was safer, which is why --all is used; in my mind, `hg resolve -m foo` should always mark it as resolved, and `--all` is how you specify "all the files", so that's why I chose `hg resolve -m --all` as the way out of `hg resolve -m` aborting. This commit makes all of this work the way it was meant to in my head :) Differential Revision: https://phab.mercurial-scm.org/D5218

test: remove changes preparing the drop of `HGMERGE` These changes are no longer necessary so we better drop them.

run-tests: define the default merge tool through configuration Using the `HGMERGE` environment variable generates confusion as it overrides any value set through configuration. By setting the default value through the default HGRC, the usual overriding rules apply and it should reduce confusion.

run-tests: explicitly declare the list of dropped environment variable It will make the list clearer and more maintainable.

test: drop usage of `HGMERGE` in `test-lfconvert.t` Using configuration instead of environment variable has a strange effect on the output, but no impact on the end result.

test: drop usage of `HGMERGE` in `test-merge-types.t` Using configuration instead of environment variable has a strange effect on the output, but no impact on the end result.

test: use the "correct" merge tool in `test-rebase-detach.t` The value of `HGMERGE` overrides the value passed through --config. We are about to drop this `HGMERGE` environment variable so we update the value used in config to match what is currently in use. This is another example of confusion introduced by the `HGMERGE` environment variable.

test: also deactivate `ui.merge` when testing merge tool We are about to introduce a default config for `ui.merge`. Since `test-merge-tools.t` is about testing merge configuration, we need to make sure it won't interfere.

tests: adjust merge tool config in test-largefiles-update.t Previously, the `ui.merge=internal:fail` configuration was shadowed by the the `HGMERGE=internal:merge` environment variable. We would like to remove this usage of `HGMERGE` variable because it is error-prone (eg: this very test). We start by cleaning up test independently to avoid large churn when the change happens.

extensions: include current version in "invalid version" message It is "not so rare" for the mercurial version to be badly detected at build time. In such case, version check for extensions gets confused. To help pinpoint the error, we now include the Mercurial's version number in the error message.