dirstate: handle missing backup file on restoration This is the stable counter part to e358f6e0e50e. Since 6.4 will stop writing undo.dirstate in some case (actually… at all), a transaction created with 6.4 and recover/rolledback with 6.3 need to work to a certain degreee. This changeset add the necessary bits so that we don't get a traceback from 6..3 in this cases.

tag: disallow tagging the working directory It's kinda silly, but a clear error message is better than a stacktrace about subscripting `None` when trying to generate the default commit message. I'm surprised that `.revsingle(..).node()` returns None instead of `nodemod.wdirid`, but now there's a test to catch if this changes.

test: fix the flakyness in test-remotefilelog-local.t I now get about 80% of my `test-chg` CI run that fails on flakyness in this tests. It turns out this is only ambiguous status that end up doing file download. So… calling status early will do that potential download separately and the calls we scrutinize during that test will be just fine.

fix: add more information to the debug output The previous debug output did not help to understand which file where fixed in which revision. The new output should cover that.

hgweb: unbyteify the 100-continue check The environment seems to be `str` or `tuple[int]`, and the same check in `wsgicgi.py` is already `str` based, so I suspect this was wrong. I think what happened here is that the string wasn't `r''` prefixed in 482d6f6dba91 like `wsgicgi.py`, so it got wrongly byteified in 687b865b95ad when converting to byte literals en masse.

setup: treat error output and non-zero return code differently Choking on Mercurial's stderr mean armless warning can derails the whole install process. We do like to be able to issue warning to people so we stop considering any stderr is a fatal mistake. This allow us to actually boostrap a version of Mercurial without loosing to many sanity point. For example in case where evolve is not loaded, something that happens when the recorded version is malformatted. Creating a wonderful ouroboros.

setup: make the version computation process more resistant The tag fetching might return and empty string¹, from there everything derails quickly. As setup tools becomes more picky about version format we make the whole seems a bit more robust. The resulting version will be obviously weird, but at least it will actually install itself. [1] This is a problem we will address in the next changesets.

bundlerepo: enforce the requirements declared by the underlying repository Previously, `hg log -r 'bundle()' -R bundle.hg` was failing for me when run from source, complaining about an unknown parent, when the system installed `hg` didn't. Some debugging showed the index was 0 length. It turned out that I didn't have the C extensions compiled, which a simple `hg log -r .` was able to indicate. The problem being that the RequirementError got handled by RepoError, which uses an empty directory as a fallback to process the bundle.

scmutil: make checknewlabel() allow "_" in otherwise numeric names (issue6737)

rust-narrow: fix loop that never loops This was caught by `clippy`. I guess the narrow tests leave something to be desired, since this previously only checked the first valid pattern.