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

purge: add -i flag to delete ignored files instead of untracked files It's convenient for deleting build artifacts. Using --all instead would delete other things too. Differential Revision: https://phab.mercurial-scm.org/D8096

pyoxidizer: use `legacy_windows_stdio` on Windows The C executable sets this too, otherwise no output shows up (when paging?). There is also `legacy_windows_fs_encoding`, but I'm not setting that for now because the C executable doesn't either. Differential Revision: https://phab.mercurial-scm.org/D8053

merge: use manifestdict.walk() instead of manifestdict.matches() As with other patches in this series, this avoids making a potentially-expensive copy of a manifest. Differential Revision: https://phab.mercurial-scm.org/D8084

manifest: rewrite filesnotin to not make superfluous manifest copies This also skips using diff() when all we care about is the filenames. I'm expecting the built in set logic to be plenty fast. For really large manifests with a matcher in play this should copy substantially less data around. Differential Revision: https://phab.mercurial-scm.org/D8082

merge with stable