tests/test-unrelated-pull

mkdir a
cd a
hg init
echo 123 > a
hg add a
hg commit -t "a" -u a -d "0 0"

cd ..
mkdir b
cd b
hg init 
echo 321 > b
hg add b
hg commit -t "b" -u b -d "0 0"

hg pull ../a
hg heads