clfilter: fallback to unfiltered version when linkrev point to filtered history
On `filectx`, linkrev may point to any revision in the repository. When the
repository is filtered this may lead to `filectx` trying to build `changectx`
for filtered revision. In such case we fallback to creating `changectx` on the
unfiltered version of the reposition. This fallback should not be an issue
because `changectx` from `filectx` are not used in complex operation that
care about filtering. It is complicated to work around the issue in a
clearer way as code raising such `filectx` rarely have access to the
repository directly.
Linkrevs create a lot of issue with filtering. It is stored in revlog entry at
creation time and never changed. Nothing prevent the changeset revision pointed
to become filtered. Several bogus behavior emerge from such situation. Those
bugs are complex to solve and not part of the current effort to install
filtering. This changeset is simple hack that prevent plain crash in favor on
minor misbehavior without visible effect.
This "hack" is longly documented in to code itself to help people that would
look at it in the future.
Test document extraction
$ "$TESTDIR/hghave" docutils || exit 80
$ HGENCODING=UTF-8
$ export HGENCODING
$ { echo C; find "$TESTDIR/../i18n" -name "*.po" | sort; } | while read PO; do
> LOCALE=`basename "$PO" .po`
> echo
> echo "% extracting documentation from $LOCALE"
> echo ".. -*- coding: utf-8 -*-" > gendoc-$LOCALE.txt
> echo "" >> gendoc-$LOCALE.txt
> LC_ALL=$LOCALE python "$TESTDIR/../doc/gendoc.py" >> gendoc-$LOCALE.txt 2> /dev/null || exit
>
> # We call runrst without adding "--halt warning" to make it report
> # all errors instead of stopping on the first one.
> echo "checking for parse errors"
> python "$TESTDIR/../doc/runrst" html gendoc-$LOCALE.txt /dev/null
> done
% extracting documentation from C
checking for parse errors
% extracting documentation from da
checking for parse errors
% extracting documentation from de
checking for parse errors
% extracting documentation from el
checking for parse errors
% extracting documentation from fr
checking for parse errors
% extracting documentation from it
checking for parse errors
% extracting documentation from ja
checking for parse errors
% extracting documentation from pt_BR
checking for parse errors
% extracting documentation from ro
checking for parse errors
% extracting documentation from ru
checking for parse errors
% extracting documentation from sv
checking for parse errors
% extracting documentation from zh_CN
checking for parse errors
% extracting documentation from zh_TW
checking for parse errors