state: import the file to write state files from evolve extension The current way of writing state files is very obscure with each state file having it's own format to store state files. There is no centralized way to write state files in a good format. Moreover the current state files are not extensible, you cannot add more data to store in state files in reliable ways. To solve the problem, I wrote my own serialization and deserialization format, looked into existing formats like Protobuf, MessagePack, JSON but CBOR looks very promising and is suggested by people in the community. The current interface to store state files is to directly write data in files when things abort. Using the class imported by this commit, we can create objects which has a dict like interface and can store data on the object and store it on the file when things abort. The evolve extension is using the state file for `evolve`, `grab` commands and using it for resolution of orphaness, phase-divergence and content-divergence. The file is moved from changeset e4ac2e2c2086f977afa35e23a62f849e9305a225 of the evolve extension which is also tagged as 7.3.0. The following changes are made to the file while moving to core: * import util from current directory as this file in mercurial/ now * make cmdstate class extend object * removed mutable default value for opts in cmdstate.__init__ * some doc changes to replace out of core things with in-core ones evolve extension can be found at https://bitbucket.org/marmoute/mutable-history Differential Revision: https://phab.mercurial-scm.org/D2591

revlog: suggest other parent when a parent was refused for a delta (issue5481) Without aggressivemergedeltas, ensure that when we decline the closest parent (by revision number), the other parent is examined too.

status: add default of --terse=u to tweakdefaults (BC) This is in line with both Git and Subversion, and strikes me as a more humane behavior. Test output changes are expected once you read test-status.t, and I feel like we've still got adequate coverage on things. Differential Revision: https://phab.mercurial-scm.org/D3628

status: add a config knob for setting default of --terse I want --terse=u basically 100% of the time, but there's not a good way to do that before this patch. I'm very unhappy with how the default value for --terse looks rigt now, but it does *work*. The alternative would be to define an "optional string" flag type using fancyopts.customopt and then use that, leaving the default as None. Does anyone have a strong preference for that, or a better idea? Differential Revision: https://phab.mercurial-scm.org/D3627

tests: port inline extensions in test-obsolete.t to Python 3 Still some lingering failure in here, but it's much better. Differential Revision: https://phab.mercurial-scm.org/D3626

py3: consolidate down some (case ...) entries Differential Revision: https://phab.mercurial-scm.org/D3625

py3: re-sort test whitelist Differential Revision: https://phab.mercurial-scm.org/D3624

tests: fix test-subrepo-paths.t on Python 3 The Python 3 group reference error message is a little more helpful, so we'll allow the extra output. I tried matching this with an (re) line, but decided it wasn't worth the effort. Differential Revision: https://phab.mercurial-scm.org/D3623

tests: fix test-parseindex2 on Python 3 parsers.versionerrortext is a sysstr, but it's only ever used in this test on the Python side, so I'm okay to just handle it like this. Differential Revision: https://phab.mercurial-scm.org/D3622

tests: use [(] instead of \( to avoid warning on py3 From a recent test run of mine: run-tests.py:1633: DeprecationWarning: invalid escape sequence '\(' This lets us encode the expectation without the badness. Differential Revision: https://phab.mercurial-scm.org/D3621