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
#
# A B
#
# 3 4 3
# |\/| |\
# |/\| | \
# 1 2 1 2
# \ / \ /
# 0 0
#
# if the result of the merge of 1 and 2
# is the same in 3 and 4, no new manifest
# will be created and the manifest group
# will be empty during the pull
#
# (plus we test a failure where outgoing
# wrongly reported the number of csets)
#
hg init a
cd a
touch init
hg ci -A -m 0 -d "1000000 0"
touch x y
hg ci -A -m 1 -d "1000000 0"
hg update 0
touch x y
hg ci -A -m 2 -d "1000000 0"
hg merge 1
hg ci -A -m m1 -d "1000000 0"
#hg log
#hg debugindex .hg/00manifest.i
hg update -C 1
hg merge 2
hg ci -A -m m2 -d "1000000 0"
#hg log
#hg debugindex .hg/00manifest.i
cd ..
hg clone -r 3 a b
hg clone -r 4 a c
hg -R a outgoing b
hg -R a outgoing c
hg -R b outgoing c
hg -R c outgoing b
hg -R b pull a
hg -R c pull a