fix backtrace printed when cannot get lock.
change lock error handling code so exceptions have useful info and
exception handling in one place.
add test case for when cannot get lock.
#!/bin/sh
hg init
echo a > a
hg add a
hg commit -m "1" -d "1000000 0"
hg status
hg copy a b
hg status
hg --debug commit -m "2" -d "1000000 0"
echo "we should see two history entries"
hg history -v
echo "we should see one log entry for a"
hg log a
echo "this should show a revision linked to changeset 0"
hg debugindex .hg/data/a.i
echo "we should see one log entry for b"
hg log b
echo "this should show a revision linked to changeset 1"
hg debugindex .hg/data/b.i
echo "this should show the rename information in the metadata"
hg debugdata .hg/data/b.d 0 | head -3 | tail -2
$TESTDIR/md5sum.py .hg/data/b.d
hg cat b > bsum
$TESTDIR/md5sum.py bsum
hg cat a > asum
$TESTDIR/md5sum.py asum
hg verify