tests/helpers-testrepo.sh

convert: correctly convert paths to UTF-8 for Subversion

The previous code using encoding.tolocal() only worked by chance in these
situations:

* The string is ASCII: The fast path was triggered and the string was returned
  unmodified.
* The local encoding is UTF-8: The source and target encoding is the same.
* The string is not valid UTF-8 and the native encoding is ISO-8859-1: If the
  string doesn’t decode using UTF-8, ISO-8859-1 is tried as a fallback. During
  `hg convert`, the local encoding is always UTF-8. The irony is that in this
  case, encoding.tolocal() behaves like what someone would expect the reverse
  function, encoding.fromlocal(), to do.

When the locale encoding is ISO-8859-15, trying to convert a SVN repo `/tmp/a€`
failed before like this:

file:///tmp/a%C2%A4 does not look like a Subversion repository to libsvn version 1.14.0

The correct URL is `file:///tmp/a%E2%82%AC`.

Unlike previously (with the ISO-8859-1 fallback), decoding the path using the
locale encoding can fail. In this case, we have to bail out, as Subversion
won’t be able to do anything useful with the path.

# 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