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
#
# test for branch handling
#
# XXX: need more tests
hg init
echo a > a
echo b > b
hg ci -A -m 0 -d "1000000 0"
echo aa > a
echo bb > b
hg ci -m 1 -d "1000000 0"
hg tag -l foo
hg update 0
hg parents -b
# test update
hg update -b foo
hg parents
# test merge
hg update 0
echo c > c
hg ci -A -m 0.0 -d "1000000 0"
hg merge -b foo
hg parents -b
# re-test with more branches
hg update -C 0
echo d > d
hg ci -A -m 0.0 -d "1000000 0"
hg merge -b foo
hg parents -b