rust-index: implementation of __getitem__
Although the removed panic tends to prove if the full test suite
did pass that the case when the input is a node id does not happen,
it is best not to remove it right now.
Raising IndexError is crucial for iteration on the index to stop,
given the default CPython sequence iterator, see for instance
https://github.com/zpoint/CPython-Internals/blobs/master/BasicObject/iter/iter.md
This was spotted by `test-rust-ancestors.py`, which does simple interations on
indexes (as preflight checks).
In `revlog.c`, `index_getitem` defaults to `index_get` when called
on revision numbers, which does raise `IndexError` with the same message as
the one we are introducing here.
# Copyright (C) 2006 - Marco Barisione <marco@barisione.org>
#
# This is a small extension for Mercurial (https://mercurial-scm.org/)
# that removes files not known to mercurial
#
# This program was inspired by the "cvspurge" script contained in CVS
# utilities (http://www.red-bean.com/cvsutils/).
#
# For help on the usage of "hg purge" use:
# hg help purge
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, see <http://www.gnu.org/licenses/>.
'''command to delete untracked files from the working directory (DEPRECATED)
The functionality of this extension has been included in core Mercurial since
version 5.7. Please use :hg:`purge ...` instead. :hg:`purge --confirm` is now
the default, unless the extension is enabled for backward compatibility.
'''
# This empty extension looks pointless, but core mercurial checks if it's loaded
# to implement the slightly different behavior documented above.
# Note for extension authors: ONLY specify testedwith = 'ships-with-hg-core' for
# extensions which SHIP WITH MERCURIAL. Non-mainline extensions should
# be specifying the version(s) of Mercurial they are tested with, or
# leave the attribute unspecified.
testedwith = b'ships-with-hg-core'