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
mkdir a
cd a
hg init
echo foo > t1
hg add t1
hg commit -m "1" -d "1000000 0"
cd ..
hg clone a b
cd a
echo foo > t2
hg add t2
hg commit -m "2" -d "1000000 0"
cd ../b
echo foo > t3
hg add t3
hg commit -m "3" -d "1000000 0"
hg push ../a
hg pull ../a
hg push ../a
hg merge
hg commit -m "4" -d "1000000 0"
hg push ../a
cd ..
hg init c
cd c
for i in 0 1 2; do
echo $i >> foo
hg ci -Am $i -d "1000000 0"
done
cd ..
hg clone c d
cd d
for i in 0 1; do
hg co -C $i
echo d-$i >> foo
hg ci -m d-$i -d "1000000 0"
done
HGMERGE=true hg merge 3
hg ci -m c-d -d "1000000 0"
hg push ../c
hg push -r 2 ../c
hg push -r 3 -r 4 ../c
hg push -r 5 ../c
exit 0