dirstate: clean up when restoring identical backups
When a dirstate backup is restored, it is possible that no actual changes to
the dirstate have been made. In this case, the backup is still a hardlink
to the original dirstate.
Unfortunately, `os.rename` silently fails (nothing happens, and no error
occurs) when `src` and `dst` are hardlinks to the same file. As a result,
the backup is left lying around. Over time, these files accumulate.
When restoring dirstate backups, check if the backup and the dirstate are
the same file, and if so, just delete the backup.
Differential Revision: https://phab.mercurial-scm.org/D1201
$ . "$TESTDIR/helpers-testrepo.sh"
Testing that hghave does not crash when checking features
$ hghave --test-features 2>/dev/null
Testing hghave extensibility for third party tools
$ cat > hghaveaddon.py <<EOF
> import hghave
> @hghave.check("custom", "custom hghave feature")
> def has_custom():
> return True
> EOF
(invocation via run-tests.py)
$ cat > test-hghaveaddon.t <<EOF
> #require custom
> $ echo foo
> foo
> EOF
$ ( \
> testrepohgenv; \
> $PYTHON $TESTDIR/run-tests.py $HGTEST_RUN_TESTS_PURE test-hghaveaddon.t \
> )
.
# Ran 1 tests, 0 skipped, 0 failed.
(invocation via command line)
$ unset TESTDIR
$ hghave custom
(terminate with exit code 2 at failure of importing hghaveaddon.py)
$ rm hghaveaddon.*
$ cat > hghaveaddon.py <<EOF
> importing this file should cause syntax error
> EOF
$ hghave custom
failed to import hghaveaddon.py from '.': invalid syntax (hghaveaddon.py, line 1)
[2]