histedit: fix diff colors The problem here is that indexing a bytestring gives you integers, not chars, so the comparison to b'+' ends up being wrong. We don't really have a way to test curses output, so no tests to verify the correctness of this behaviour.

dirstate: fix a potential traceback when in `copy` and `rename` Before this changes, calling `hg copy` or `hg rename` could trigger a traceback about using an invalidated dirstate. This wasn't caught by the test as it needed the blackbox extension to preload the dirstate first in a way "refresh" invalidates it. Changing the context creation patterns fixes it.

dirstate: fix the bug in [status] dealing with committed&ignored directories In particular, these directories can "infect" their sibling directories with ignored status due to using a shared memoization cell by accident. This fixes bug #6795.

tests: demonstrate a bug with committed&ignored dirs

rust: remove out-of-date comment We've migrated to a newer version of Rust, so it doesn't make sense anymore.

rust: upgrade `rayon` dependency This includes a potential soundness fix as well as some improvements to performance which should be helpful.

rust: update zstd dependency Let's try to be the most up-to-date for this cycle. Fedora already has this version packaged, it's an added bonus.

fastexport: rework newline logic Newlines should only be added when otherwise the stream would look weird without them (on blobs), therefore they are the exception. Flip the logic so they are added, not skipped.

tests: simplify a bit

dirstate-v2: fix an incorrect handling of readdir errors Make sure not to cache the results of a failed readdir call.