rust-dirstate: add "dirs" Rust implementation Following the work done in d1786c1d34fa and working towards the goal of a complete Rust implementation of the dirstate, this rewrites the `dirs` class. There is already a C implementation, which relies heavily on CPython hacks and protocol violations for performance, so I don't expect this to perform as well for now, as this is very straight-forward code. The immediate benefits are new high-level documentation and some unit tests. Differential Revision: https://phab.mercurial-scm.org/D6393

relnotes: added description about statemod._statecheck Differential Revision: https://phab.mercurial-scm.org/D6557

statecheck: shifted defaults to addunfinished() This shifts the definitions and defaults of `_statecheck()` class to `addunfinished()` registration method. Differential Revision: https://phab.mercurial-scm.org/D6583

statecheck: added support for cmdutil.afterresolvedstates This removes `afterresolvedstates` from `cmdutil` and adds support for it in `_statecheck` class. A new flag `continueflag` is added to the class to check whether an operation supports `--continue` option or not. Tests remain unchanged. Differential Revision: https://phab.mercurial-scm.org/D6551

statecheck: added support for STATES This removes `STATES` from `state.py` and adds support to `statecheck` class to handle its features. `getrepostate()` function is modified accordingly. This adds a method 'cmdutil.addunfinished()' for appending to the unfinishedstate list so as to keep 'merge' and 'bisect' at the last. This also makes two separate message formats for `checkunfinished()` and `getrepostate()` as there were previously present. Results of test changed are shown. Differential Revision: https://phab.mercurial-scm.org/D6503

state: moved cmdutil.STATES and utilities to state.py This commit moves `cmdutil.STATES` and adjoining functions to `state.py`. The existing users are updated accordingly. Tests remain unchanged. Differential Revision: https://phab.mercurial-scm.org/D6502

state: created new class statecheck to handle unfinishedstates For the purpose of handling states for various multistep operations like `hg graft`, `hg histedit`, `hg bisect` et al a new class called statecheck is created .This will help in having a unified approach towards these commands and handle them with ease. The class takes in 4 basic arguments which include the name of the command, the name of the state file associated with it , clearable flag , allowcommit flag. This also also adds the support of`checkunfinished()` and `clearunfinished()` to the class. Tests remain unchanged. Differential Revision: https://phab.mercurial-scm.org/D6501

states: moved cmdutil.unfinishedstates to state.py This moves `cmdutil.unfinishedstates`, `checkunfinished()`,`clearunfinished()` to `state.py`. the already existing users of this module are updated accordingly. Test results remain unchanged. Differential Revision: https://phab.mercurial-scm.org/D6484

rebase: fix in-memory rebasing of copy of empty file Classic Python mistake of unintentionally treating None and empty string the same. Differential Revision: https://phab.mercurial-scm.org/D6570

tests: demonstrate broken in-memory rebase of copy to empty file Differential Revision: https://phab.mercurial-scm.org/D6569

zsh: enable completion support for chg as well When verifying this change, you may need to clear/rebuild the completion cache; I did this by deleting the ~/.zcompdump file and then starting a new shell. Differential Revision: https://phab.mercurial-scm.org/D6574

py3: make catapult usable from the test runner in py3 Differential Revision: https://phab.mercurial-scm.org/D6577

py3: use integer division for the value passed to xrange Differential Revision: https://phab.mercurial-scm.org/D6576

pycompat: make fewer assumptions about sys.executable There are many Python "bundlers" which create an archive to run a Python binary from, and they may not set sys.executable at all - handle that case properly, especially to run tests. Differential Revision: https://phab.mercurial-scm.org/D6575

update: fix spurious unclean status bug shown by previous commit The crux of the problem is: - the dirstate is corrupted (the sizes/dates are assigned to the wrong files) - because when worker.worker is used with a return value (batchget in merge.py here), the return value when worker.worker effectively parallelizes is permuted - this is because worker.worker's partition of input and combination of output values are not inverses of one another: it split [1,2,3,4,5,6] into [[1,3,5],[2,4,6]], but combines that into [1,3,5,2,4,6]. Given that worker.worker doesn't call its function argument on contiguous chunks on the input arguments, sticking with lists means we'd need to know the relation between the inputs of worker.worker function argument (for instance, requiring that every input element is mapped to exactly one output element). It seems better to instead switch return values to dicts, which can combined reliably with a straighforward restriction. Differential Revision: https://phab.mercurial-scm.org/D6581