discovery: using the new basesheads() Our ultimate goal is to switch eventually to a Rust implementation, but this move actually seems to increase the performance in a pure Python build. What follows is a quick measurement done on PyPy on repos prepared with `contrib/discovery-helper.sh 50 100`. Before: ! wall 0.894384 comb 0.890000 user 0.890000 sys 0.000000 (best of 11) ! wall 0.971199 comb 0.970000 user 0.950000 sys 0.020000 (max of 11) ! wall 0.927993 comb 0.925455 user 0.919091 sys 0.006364 (avg of 11) ! wall 0.921619 comb 0.920000 user 0.910000 sys 0.010000 (median of 11) After: ! wall 0.614278 comb 0.610000 user 0.610000 sys 0.000000 (best of 14) ! wall 0.789459 comb 0.790000 user 0.770000 sys 0.020000 (max of 14) ! wall 0.722765 comb 0.720000 user 0.715714 sys 0.004286 (avg of 14) ! wall 0.734448 comb 0.720000 user 0.720000 sys 0.000000 (median of 14) Differential Revision: https://phab.mercurial-scm.org/D5583

ancestor: incrementalmissingancestors.basesheads() This new method will avoid the need to access the `bases` attribute directly in `setdiscovery`, and to prefilter `nullrev` before passing it to the `heads()` revset. Being a method, it can transparently be reimplemented in a Rust (or any native) version. Differential Revision: https://phab.mercurial-scm.org/D5582

rust-cpython: set conversion for MissingAncestors.bases() Also I hope that the separate `py_set()` helper will help transition to proper `PySet` support in `rust-cpython` Took the opportunity to replace explict for loop with iteration and collect(). Differential Revision: https://phab.mercurial-scm.org/D5581

rust: dagop.headrevs() Rust counterparts This introduces two Rust implementations for `mercurial.dagop.headrevs`. The algorithm is identical to the Python version. Depending on the caller, one or the other could be the most practical, or the most performant, by minimizing the amount of memory copy and allocations. Differential Revision: https://phab.mercurial-scm.org/D5580

rust: factorized testing Graphs it will useful to use these outside of `ancestors`, too. Differential Revision: https://phab.mercurial-scm.org/D5579

rust-cpython: moved generic conversion fn out of ancestors module This will allow to use it easily from other submodules Differential Revision: https://phab.mercurial-scm.org/D5578

revset: transparently forward _intlist argument in all case We took a safe approach for the first take, we can get bolder now.

narrow: reuse narrowspec.updateworkingcopy() when narrowing Similar to the previous patch for widening, but here we also need to teach updateworkingcopy() to forcefully delete files that are not recorded in the dirstate as clean. That should be safe because the narrowing command (e.g. `hg tracked --removeinclude`) has already checked that the working copy is clean. Differential Revision: https://phab.mercurial-scm.org/D5511

narrow: reuse narrowspec.updateworkingcopy() when widening The widening of the working copy we do after widening a repo is practically the same as we do in a repo share after the store narrowspec has been changed in a different share. Let's reuse the code for that that we now have in the narrowspec module. Differential Revision: https://phab.mercurial-scm.org/D5510

narrow: move copytonarrowspec() out of setnarrowpats() I think it was a mistake to write the working copy's narrowspec every time the store narrowspec is written. This starts separating those actions. Differential Revision: https://phab.mercurial-scm.org/D5509