dirstate: introduce an internal `_remove` method We want to split current user of `dirstate.remove` between `hg rm`-like cases and update of the dirstate coming from update/merge. To do this we will introduce new API. The first step is to introduces an internal function that these new API migh use (or not use) to distinct between the migrated users and the others. Differential Revision: https://phab.mercurial-scm.org/D11011

dirstate: introduce an internal `_add` method We want to split current user of `dirstate.add` between `hg add`-like cases and update of the dirstate coming from update/merge. To do this we will introduce new API. The first step is to introduces an internal function that these new API migh use (or not use) to distinct between the migrated users and the others. Differential Revision: https://phab.mercurial-scm.org/D11010

run-tests: rely on an actual executable in PATH instead of alias for `hg` The alias approach is poorly inherited by other process that the test might spawn. To solve this we use the same approach as for `python`/`python3` we write an executable file explicitly. Doing this fixes `which hg` invocation that now returns the same location as `hg`. Using chg server side has some minor effect on some stdout/stderr ordering when using `chg` as the server too. Differential Revision: https://phab.mercurial-scm.org/D11053

tests: blacklist a handful of test with `rhg` or `chg` The use of `alias` to enforce `chg` and `rhg` means we are actually using a mix of `rhg`/`chg` and `hg` when calling `hg` in the test. Fixing this breaks various tests. This would be a large detour to fix that. I am disabling them for now with an appropriate comment. We would hopefully get back to them by the 5.8 release. Differential Revision: https://phab.mercurial-scm.org/D11052

run-tests: use more explicit signaling for `chg` Using a dedicated variable is clearer and less fragile. It cannot hurt. Differential Revision: https://phab.mercurial-scm.org/D11051

run-tests: drop the `rhg` flag for `hghave.py` if unset This seems cleaner. Differential Revision: https://phab.mercurial-scm.org/D11050

run-tests: introduce a `HGTEST_REAL_HG` variable for test It turns out that currently, `hg` and `which hg` can point to different things because `hg` is an alias… This is annoying because script and pieces of test are unknowingly using the wrong `hg`. We will fix it in another changeset. However some test actually need to use a real `hg` binary and not some `chg` or `rhg` equivalent. So we introduce a new variable with the right value and we put it to us in the appropriate location. Differential Revision: https://phab.mercurial-scm.org/D11049

run-test: clarify the error with a bad --with-hg is passed This helped me to understand what was going on when I got into trouble. Differential Revision: https://phab.mercurial-scm.org/D11046

windows: make sure we fully read and cleanly close the connection Maybe this will prevent server on Windows to sometimes complains about the client closing the connection too soon. So we make sure we read everything and we officially close the connection. Hopefully Windows will be happier and the test will stop being flaky. Differential Revision: https://phab.mercurial-scm.org/D11073

test-bookmark: clarify the path involved in a pull creating divergence This make the test easier to follow. Especially because this part is currently failing on windows. Differential Revision: https://phab.mercurial-scm.org/D11056