tests/helpers-testrepo.sh

dispatch: change cwd when loading local config

Previously, the `_getlocal` function would not correctly load the repo config
when given a relative `rpath` and an alternate cwd via the `wd` parameter.

Normally when `--cwd` is specified, hg changes to the given directory before
attempting to load the local config (and therefore does not specify a `wd`).
The only time the function is called with `wd` set is when hg is running as a
command server (e.g., with chg), in which case each forked worker process will
attempt to configure itself via `_getlocal` before responding to the client.
When given a relative repo path, the worker fails to load the repo config,
detects a config mismatch with the client, and enters a redirect/respawn loop.

To fix this, we can simply change to the desired working directory during
config loading. (Note that simply concatenating `wd` and `rpath` won't work
in all cases. The repo path could be something more complicated than a simple
relative path, such as a `union:` repo.)

# 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