tests: add blank output lines to test-commandserver This helps the import checker notice when a Python heredoc has ended. It's not perfect, but it gets nasty quick and I think the better fix would be to add a real parser for .t-tests, which will have to wait.

contrib: make import-checker agree more with run-tests about heredocpy run-tests.py and import-checker.py take wholly different approaches to .t-tests, and the result was that they had different notions about when a Python heredoc had ended, leading to conflicts. This resolves part of the issue, and the rest I can deal with by tweaking the one offending test file.

contrib: add bzrlib to list of packages from which we import symbols Helps some tests pass the import checker.

tests: ensure demandimport test uses absolute_import

tests: blacklist test-demandimport from test-check-module-imports It just does too much weird import stuff to have a hope of passing the checks.

tests: sort excluded test files in test-check-module-imports

contrib: allow symbol imports from hgclient for tests

tests: blacklist some more entries in module import checks

bookmarks: allow deleting active bookmark using '.'

template: add minimal obsfate template function The goal of this series is to have templates capable of displaying the evolution of a changeset in a clean and human-readable way. Add the succsandmarkers template return successors and markers so it can be used separately like this: > {succsandmarkers % "{get(succsandmarkers, "markers")|json};"} The following patches will add template functions that takes successors and markers as inputs and compute various obsfate fields from them.

obsolete: track markers in _succs We now also store markers in _succs. It will be useful for the obsfate template that will use them to display more meaningful information like the list of users that have evolved a changeset into its successors.

obsolete: add an explicit '_succs.copy()' method Mimic the standard API for copying in the _succs class, it makes the code slightly cleaner and will be needed later for copying markers at the same time than copying the list content.

obsolete: introduce a _succs class It will be useful later when we will be adding markers to _succs in order to represent a successorset with the list of markers from the root to each successors sets. This information will be needed for the obsfate template I will introduce. Makes it a subclass of list so all callers will continue to work.

simplemerge: simplify code now that we always write to a context There's no need for an `out` abstraction between files and contexts anymore. Differential Revision: https://phab.mercurial-scm.org/D383

simplemerge: make context parameters non-optional Also update the function docstring. Differential Revision: https://phab.mercurial-scm.org/D382

simplemerge: stop accepting, and passing, file parameters Differential Revision: https://phab.mercurial-scm.org/D381

simplemerge: stop reading from, and writing to, files We now use contexts first for everything and also pass them everywhere. Differential Revision: https://phab.mercurial-scm.org/D380

simplemerge: use context paths for default labels instead of file paths This is the last place we used the filepath arguments without first using the context version. Differential Revision: https://phab.mercurial-scm.org/D379

contrib: make simplemerge script pass context-like objects `simplemerge()` will soon require context-like objects to work. Create a simple context-like object that wraps the requested files and can be passed to the new API. Differential Revision: https://phab.mercurial-scm.org/D378

simplemerge: use `ctx.decoddeddata()` instead of `repo.wreaddata` This eliminates the need for the `repo` object. Differential Revision: https://phab.mercurial-scm.org/D435

context: add `decodeddata()` to basefilectx This will be used as an abstraction by simplemerge to get the data it used to read off the filesystem. Differential Revision: https://phab.mercurial-scm.org/D434

bookmarks: allow renaming active bookmark using '.'

i18n: update check-translation script to pass import checker

demandimportpy3: update to pass import checker

contrib: always treat importlib.* as stdlib

hg: update top-level script to use modern import conventions

simplemerge: update to conform with modern import conventions

contrib: inform import checker that __builtin__ is a thing

contrib: allow importing "symbols" from mercurial

hgperf: update to conform with import style checks