mercurial/helptext/extensions.txt

test: simplify test-amend.t to avoid race condition

Insted on relying on sleep, we could simply have the editor do the file change.
This remove the reliance on "sleep" and avoid test failing on heavy load
machine.

To test this, I reverted the code change in 5558e3437872 and the test started
failing again.

This is a graft on stable of 141ceec06b55 which should have targeted for stable.

Differential Revision: https://phab.mercurial-scm.org/D8103

Mercurial has the ability to add new features through the use of
extensions. Extensions may add new commands, add options to
existing commands, change the default behavior of commands, or
implement hooks.

To enable the "foo" extension, either shipped with Mercurial or in the
Python search path, create an entry for it in your configuration file,
like this::

  [extensions]
  foo =

You may also specify the full path to an extension::

  [extensions]
  myfeature = ~/.hgext/myfeature.py

See :hg:`help config` for more information on configuration files.

Extensions are not loaded by default for a variety of reasons:
they can increase startup overhead; they may be meant for advanced
usage only; they may provide potentially dangerous abilities (such
as letting you destroy or modify history); they might not be ready
for prime time; or they may alter some usual behaviors of stock
Mercurial. It is thus up to the user to activate extensions as
needed.

To explicitly disable an extension enabled in a configuration file of
broader scope, prepend its path with !::

  [extensions]
  # disabling extension bar residing in /path/to/extension/bar.py
  bar = !/path/to/extension/bar.py
  # ditto, but no path was supplied for extension baz
  baz = !