help: add a mechanism to change flags' help depending on config It seems reasonable to have a similar mechanism for the rest of the help, but no such thing is implemented. The goal is to make the help of commands clearer in the presence of significant default changes, like tweakdefaults or with company-wide hgrcs. In these cases, a user looking at the help of a command doesn't exactly know what his hgrc is doing. Apply to this to the --git option of commands that display diffs, as this option in particular causes confusion for some reason. Differential Revision: https://phab.mercurial-scm.org/D8100

lfs: use str for the open() mode when opening a blob for py3 The other fix for this was to leave the mode as bytes, and import `pycompat.open()` like a bunch of other modules do. But I think it's confusing to still use bytes at the python boundary, and obviously error prone. Grepping for ` open\(.+, ['"][a-z]+['"]\)` and ` open\(.+, b['"][a-z]+['"]\)` outside of `tests`, there are 51 and 87 uses respectively, so it's not like this is a rare direct usage. Differential Revision: https://phab.mercurial-scm.org/D8099

rust-dirstatemap: cache non normal and other parent set Performance of `hg update` was significantly worse since the introduction of the Rust `dirstatemap`. This regression was noticed by Valentin Gatien-Baron when working on a large repository, as it goes unnoticed for smaller repositories like Mercurial itself. This fix introduces the same getter/setter mechanism at `hg-core` level as for `set/get_dirs`. While this technique is, as previously discussed, quite suboptimal, it fixes an important enough problem. Refactoring `hg-core` to use the typestate pattern could be a good approach to improving code quality in a future patch. Differential Revision: https://phab.mercurial-scm.org/D8048

tags: behave better if a tags cache entry is partially written This is done by discarding any partial cache entry, instead of filling the partial cache entry with 0xff before. Differential Revision: https://phab.mercurial-scm.org/D8095

tags: show how hg behaves if a tags cache entry is truncated I'm seeing an error of this form in production on the order of once a month. I'm not sure how it happens, but I suspect interrupting a pull might result in half written cache entries. Differential Revision: https://phab.mercurial-scm.org/D8094

tags: add a debug command to display .hg/cache/hgtagsfnodes1 Differential Revision: https://phab.mercurial-scm.org/D8093