Summary:
D13853115 adds `edenscm/` to `sys.path` and code still uses `import mercurial`.
That has nasty problems if both `import mercurial` and
`import edenscm.mercurial` are used, because Python would think `mercurial.foo`
and `edenscm.mercurial.foo` are different modules so code like
`try: ... except mercurial.error.Foo: ...`, or `isinstance(x, mercurial.foo.Bar)`
would fail to handle the `edenscm.mercurial` version. There are also some
module-level states (ex. `extensions._extensions`) that would cause trouble if
they have multiple versions in a single process.
Change imports to use the `edenscm` so ideally the `mercurial` is no longer
imported at all. Add checks in extensions.py to catch unexpected extensions
importing modules from the old (wrong) locations when running tests.
Reviewed By: phillco
Differential Revision: D13868981
fbshipit-source-id: f4e2513766957fd81d85407994f7521a08e4de48
If an extension was loaded but disabled due to a minimumhgversion check it
will be present in the _extensions map, but set to None. The rest of the
extensions code treats the extension as if it were not present in this case,
but the afterloaded() function called the callback with loaded=True.
