In this test, there are more than one sink with the same name in the
destination, and more than one source with that name in the source file.
-- source --
//copy:start dest one
a
b
c
//copy:stop
d
//copy:start dest two
e
//copy:stop
//copy:start dest one
f
g
//copy:stop
h
-- dest --
//copy:sink one
//copy:sink two
//copy:sink one
-- want --
//copy:sink one from source
// DO NOT MODIFY below vvvv
a
b
c
f
g
// DO NOT MODIFY above ^^^^
//copy:endsink one
//copy:sink two from source
// DO NOT MODIFY below vvvv
e
// DO NOT MODIFY above ^^^^
//copy:endsink two
//copy:sink one from source
// DO NOT MODIFY below vvvv
a
b
c
f
g
// DO NOT MODIFY above ^^^^
//copy:endsink one