Correct optimization from 3464f5e77f34; add a test.
If there are two (or more) heads that point to the same .hgtags
node, we can safely skip parsing the file in all but the last head.
(In 3464f5e77f34, we were parsing the file in the first head and
skipping all the others.)
#!/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.i
hg cat b > bsum
$TESTDIR/md5sum.py bsum
hg cat a > asum
$TESTDIR/md5sum.py asum
hg verify