revbranchcache: factor logic to write names and revs in separate functions Before this patch, the write function was so populated with upto 4 level of indentation, it was hard to understand what's going on. Differential Revision: https://phab.mercurial-scm.org/D6291

tests: make log style a little easier to read in test-copytrace-heuristics.t Revision numbers are much shorter and easier to read (especially compared to the full nodeids that were used here), so I switched to that. That's also what almost all the commands used (e.g. `hg rebase -s . -d 1`). I updated the two instances that used nodeids. I also made some other little cleanups to the log templates. Differential Revision: https://phab.mercurial-scm.org/D6279

tests: avoid cryptic nodeids in tests/test-rename-merge1.t These two nodeids had not been part of any output before, so one can't know which revision they refer to without adding something like `hg log` before them. It turned out that '.^' was equivalent for both of them, so that's what I replaced them with. Differential Revision: https://phab.mercurial-scm.org/D6280

tests: defines aliases for `hg log` calls in test-copytrace-heuristics.t This also makes the test cases more consistent since a few had missed the ":" in "changeset:" that the others used. Differential Revision: https://phab.mercurial-scm.org/D6278

rust-discovery: implementing and exposing stats() This time, it's simple enough that we can do it in all layers in one shot. Differential Revision: https://phab.mercurial-scm.org/D6233

rust-discovery: cpython bindings for the core logic As previously done with the ancestors submodule, testing for the bindings is provided from Python on a trivial case. Differential Revision: https://phab.mercurial-scm.org/D6232

rust-discovery: starting core implementation Once exposed to the Python side, this core object will avoid costly roundtrips with potentially big sets of revisions. This changeset implements the core logic of the object only, i.e., manipulation of the missing, common and undefined set-like revision attributes. Differential Revision: https://phab.mercurial-scm.org/D6231

rust-dagops: roots Unsuprisingly, the algorithm is much easier than for heads, provided we work on a set in the first place. To improve the signature, a trait for set-likes object would be useful, but that's not an immediate concern. Differential Revision: https://phab.mercurial-scm.org/D6230

rust-dagops: range of revisions This is a Rust implementation for what reachableroots2() does if includepath is True. The algorithmic details and performance notes are included in the documentation comment. Our main use case for now is a Rust counterpart of the partialdiscovery object, so we don't really need bindings yet. Differential Revision: https://phab.mercurial-scm.org/D6229

narrow: also warn when not deleting untracked or ignored files Differential Revision: https://phab.mercurial-scm.org/D6265