tests/test-strict.t

extensions: load help from hgext.__index__ as a fallback this time

Prior to 843418dc0b1b, `hgext.__index__` was consulted first if present, which
caused the longer help from the extension modules to be ignored, even when
available.  But that change causes a bunch of test failures when the pyoxidized
binary bundles *.pyc in the binary, saying the there's no help topic for
`hg help $disabled_extension` and suggesting the use of `--keyword`, rather than
showing a summary and indicating that it is disabled.  Current failures were in
test-check-help.t, test-extension.t, test-help.t, and test-qrecord.t.

Ideally, we would read the various *.pyc files from memory and slurp in the
docstring, but I know that they used to not be readable as resources, and I
can't figure out how to make it work now.  So maybe 3.9 and/or the current
PyOxidizer doesn't support it yet.  I got closer in py2exe with
`importlib.resources.open_binary("hgext", "rebase.pyc")`, but `open_binary()` on
*.pyc fails in pyoxidizer.[1]  Either way, the *.pyc can't be passed to
`ast.parse()` as `extensions._disabledcmdtable()` is doing, so I'm setting that
aside for now.

[1] https://github.com/indygreg/PyOxidizer/issues/649

  $ hg init repo
  $ cd repo

  $ echo a > a
  $ hg ci -Ama
  adding a

  $ hg an a
  0: a

  $ hg --config ui.strict=False an a
  0: a

  $ echo "[ui]" >> $HGRCPATH
  $ echo "strict=True" >> $HGRCPATH

  $ hg an a
  hg: unknown command 'an'
  (use 'hg help' for a list of commands)
  [10]
  $ hg annotate a
  0: a

should succeed - up is an alias, not an abbreviation

  $ hg up
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved