fix parsing of tags. make parse errors useful. add new tag tests. old code read every head of .hgtags. delete and recreate of .hgtags gave new head, but if error in deleted rev, .hgtags had error messages every time it was parsed. this was very hard to fix, because deleted revs hard to get back and update, needed merges too. new code reads .hgtags on every head. advantage is if parse error happens with new code, is possible to fix them by editing .hgtags on a head and committing. NOTE: new code uses binary search of manifest of each head to be fast, but still much slower than old code. best thing would be to have delete record stored in filelog so we never touch manifest. could find live heads directly from filelog. this is more work than i want now. new tests check for parse of tags on different heads, and inaccessible heads created by delete and recreate of .hgtags.

#!/bin/sh
#
# Corrupt an hg repo with two pulls.
#

# create one repo with a long history
hg init source1
cd source1
touch foo
hg add foo
for i in 1 2 3 4 5 6 7 8 9 10; do
    echo $i >> foo
    hg ci -m $i
done
cd ..

# create one repo with a shorter history
hg clone -r 0 source1 source2
cd source2
echo a >> foo
hg ci -m a
cd ..

# create a third repo to pull both other repos into it
hg init corrupted
cd corrupted
# use a hook to make the second pull start while the first one is still running
echo '[hooks]' >> .hg/hgrc
echo 'prechangegroup = sleep 5' >> .hg/hgrc

# start a pull...
hg pull ../source1 &

# ... and start another pull before the first one has finished
sleep 1
hg pull ../source2 2>/dev/null

# see the result
wait
hg verify