changelog: mention user merging in the changelog

evolve: consider using three way merge to get the user for div resolution This patch adds the logic to merge the users from two divergent csets considering the base (i.e three way merge). The case when all the three are different, we concatenate the two authors of divergent csets.

evolve: add tests for the case when div csets has different users

branching: merge with stable

evolve: move status msg to verbose mode in content-divergence resolution As suggested by Pierre-Yves, lets move these too verbose message for the user to verbose mode to decrease some noise.

debian: Override default value for SPHINXBUILD in docs/makefile Sphinx now defaults to Python 3 in Debian Buster, so we need to explicitly select the Python 2 version of sphinx-build for building docs.

docs: add SPHINXBUILD make variable This defaults to sphinx-build. The current use case is for the Evolve Debian package build.

topic: add test to increase code coverage in case of multiple topics This patch adds a test which cover the part that when we have one topic on top of other topic, this make sure that when evolving it's boundary are the current active topic (i.e hg stack)

changelog: --no-update is the default, recommend --update instead

topic: drop support for accessing csets in branch stack using bxx (issue6119) When topic extension is enabled and we have some cset whose hash is `b1234`, topic extension thinks that we are accessing 1234 cset in current branch stack. However that's not the case generally. Also I am not sure many people use this bxxx thing. Since we have a generic sxxx way to access csets, let's drop support for accessing csets using bxx which leads to bad behavior. Looking at the tests, we don't show bxxx in hg stack output anymore. I update the test to use sxxx instead of bxxxx.

legacy: drop the check for `obsolete._enabled` This looks like an ancient version check, and presumably `minimumhgversion` will do the same thing.

docs: drop references to the old temporary commit that was created with amend The sharing.rst page also mentions amend, but the diagrams aren't showing, so I'm not sure if they're in some other repo and needing to be updated.

templatekw: add `instabilities` alias for `troubles` Per https://www.mercurial-scm.org/wiki/CEDVocabulary

revset: switch internal uses and tests to `predecessors` from legacy name

revset: add `predecessor` aliases for `precursors` and `allprecursors` Per https://www.mercurial-scm.org/wiki/CEDVocabulary

revset: add `unstable` alias for `troubled` Per https://www.mercurial-scm.org/wiki/CEDVocabulary. The old name is still available (but undocumented) for compatibility. `Orphan` was renamed from `unstable` in core in 4.4, so this seems safe to do now.

docs: change `bumped` references to `phase-divergent` Per https://www.mercurial-scm.org/wiki/CEDVocabulary

docs: change `divergent` references to `content-divergent` Per https://www.mercurial-scm.org/wiki/CEDVocabulary

docs: change `troubled` references to `unstable` Per https://www.mercurial-scm.org/wiki/CEDVocabulary

docs: change `unstable` references to `orphan` Per https://www.mercurial-scm.org/wiki/CEDVocabulary

doc: correct a typo

docs: change `troubles` references to `instability` Per https://www.mercurial-scm.org/wiki/CEDVocabulary. There are a couple instances of 'troublesome' which probably need a word, as deriviatives of 'instability' didn't really fit. At least some of these are in the unlinked obs-terms.rst page.

docs: change `precursors` references to `predecessors` Per https://www.mercurial-scm.org/wiki/CEDVocabulary

docs: import figure diagrams with inkscape 0.92 No changes to the content here. This simply accepts the default option ("This file contains digital artwork for screen display") on the prompt when first opened, which is trying to upgrade from 90DPI to 96DPI.

messages: standardize on "working copy is now at" including "is" It seemed that we mostly used "is", but `hg next` and `hg prune` could print it without the "is".

evolve: move more of the progress-related variables together

evolve: delete dead calculation of number of troubled revisions The "count" variable is recalculated in the regular (no --continue) code path and it isn't used anywhere else (it used to be set to 1 in the --continue code path, but that now has its own progress counting).

evolve: drop nested locks and transactions All callers of _solveone() now take the locks and start the transactions, so there's no need to do that anymore.

next: start transaction before calling _solveone() All other callers do this, and I'm about to make _solveone() not create a transaction.

evolve: use single transaction also when continuing

evolve: run in a single transaction This speeds up `hg evolve --all` of a stack of 24 commits in the hg repo from 11.5s to 3.7s (3x). As can be seen in the tests, it also avoid some warnings about transiently unstable commits.

evolve: extract function for solving one revision, including merges Will make the next patch simpler.