perf: add two more missing b prefixes for Python 3 # skip-blame just two more b prefixes Differential Revision: https://phab.mercurial-scm.org/D5425

match: fix doctest to use bytes instead of str Fixes doctests on Python 3. Differential Revision: https://phab.mercurial-scm.org/D5423

py3: use pycompat.bytechr() instead of chr() in test-fastannotate-revmap.py This makes the test pass on Python 3. Differential Revision: https://phab.mercurial-scm.org/D5422

py3: add a missing b'' prefix in contrib/perf.py # skip-blame because just b'' prefixes This fixes test-contrib-perf.t on Python 3 which started failing. Differential Revision: https://phab.mercurial-scm.org/D5421

py3: use '%d' for integers instead of '%s' This should fix test-rebase-inmemory.t which started failing on Python 3 after recent changes. Differential Revision: https://phab.mercurial-scm.org/D5420

py3: whitelist another passing test caught by buildbot Differential Revision: https://phab.mercurial-scm.org/D5419

py3: fix bad escapes of sub() replacement pattern in test-template-basic.t Python 3.7 starts complaining about it. We have to double the backslash or '\x5c' to get around.

perfdiscovery: benching findcommonheads() This works between the local repo and any peer given by its path, and should be useful for further work on discovery Differential Revision: https://phab.mercurial-scm.org/D5418

merge with stable

templatefuncs: specialize "no match" value of search() to allow % operation If Python had Maybe or Option, the type of the search() result would be Option<Mapping>, which can be considered as a 0/1 container of a Mapping. So it makes sense that {search(r'no match pattern', x) % "whatever"} is mapped to an empty string.

templatefuncs: add regexp search() function that extracts substring This can be used to extract an issue number from a commit message, for example: {search(r'\(issue([0-9]*)\)', desc) % '{1}'}

rust: changed Graph.parents to return [Revision; 2] This will allow for simple iteration on parent revisions, such as: for parent in graph.parents(rev)?.iter().cloned() This seems to be a zero overhead abstraction once built in release mode. Differential Revision: https://phab.mercurial-scm.org/D5415

rust: improved docstring In the previous wording, rustfmt wanted to cut at the == which is not very readable in my taste. Differential Revision: https://phab.mercurial-scm.org/D5414

revset: move subscript relation functions to its own dict This will help adding more relation functions in extensions. We skip short names (that consist of one letter) while raising UnknownIdentifier because such names cannot be suggested anyway: the similarity cutoff in dispatch._getsimilar() is currently 0.6.

py3: teach run-tests.py to handle exe with spaces when --local isn't specified This was the reason that no amount of quoting worked in test-hghave.t. `os.popen()` needed to be swapped out because while the added quoting around line 3124 worked on py3, it failed on py2. See 38d51371792b. The problem with `os.system()` was wrongly splitting the command on the space in 'Program Files', regardless of quoting. It looks like there are a few other instances of `os.system()` in core code, so presumably those should be replaced?