revlog: always enable generaldelta on version 2 revlogs
This commit starts the process of diverging version 2 revlogs
from version 1 revlogs.
generaldelta is a useful feature and has been enabled by
default for ages. I can't think of a good reason why the
feature should be disabled. Yes, it is true changelogs
today don't have generaldelta enabled. But that's because
they don't have delta chains enabled, so generaldelta makes
no sense there.
This commit makes generaldelta always enabled on version 2
revlogs.
As part of this, one-off code in changelog.py mucking with
revlog.version had to be made conditional on the revlog
version, as we don't want to change revlog feature
flags on version 2 revlogs. The fact this code exists
is horrible and stems from revlog options being shared by
the opener. We probably want a better API here. But that can
wait for another patch.
Differential Revision: https://phab.mercurial-scm.org/D5561
# In most cases, the mercurial repository can be read by the bundled hg, but
# that isn't always true because third-party extensions may change the store
# format, for example. In which case, the system hg installation is used.
#
# We want to use the hg version being tested when interacting with the test
# repository, and the system hg when interacting with the mercurial source code
# repository.
#
# The mercurial source repository was typically orignally cloned with the
# system mercurial installation, and may require extensions or settings from
# the system installation.
if [ -n "$HGTESTEXTRAEXTENSIONS" ]; then
for extension in $HGTESTEXTRAEXTENSIONS; do
extraoptions="$extraoptions --config extensions.$extension=!"
done
fi
syshg () {
(
syshgenv
exec hg "$@"
)
}
# Revert the environment so that running "hg" runs the system hg
# rather than the test hg installation.
syshgenv () {
. "$HGTEST_RESTOREENV"
HGPLAIN=1
export HGPLAIN
}
# The test-repo is a live hg repository which may have evolution markers
# created, e.g. when a ~/.hgrc enabled evolution.
#
# Tests may be run using a custom HGRCPATH, which do not enable evolution
# markers by default.
#
# If test-repo includes evolution markers, and we do not enable evolution
# markers, hg will occasionally complain when it notices them, which disrupts
# tests resulting in sporadic failures.
#
# Since we aren't performing any write operations on the test-repo, there's
# no harm in telling hg that we support evolution markers, which is what the
# following lines for the hgrc file do:
cat >> "$HGRCPATH" << EOF
[experimental]
evolution = createmarkers
EOF
# Use the system hg command if the bundled hg can't read the repository with
# no warning nor error.
if [ -n "`hg id -R "$TESTDIR/.." 2>&1 >/dev/null`" ]; then
alias testrepohg=syshg
alias testrepohgenv=syshgenv
else
alias testrepohg="hg $extraoptions"
alias testrepohgenv=:
fi