t6029 already checks if subtree available and works like recursive. This
patch adds code to test test the extra functionality the subtree merge
strategy provides.
Signed-off-by: Miklos Vajna <vmiklos@frugalware.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
An earlier commit e1b3a2c (Build-in merge-recursive) made the
subtree merge strategy backend unavailable. This resurrects
it.
A new test t6029 currently only tests the strategy is available,
but it should be enhanced to check the real "subtree" case.
Signed-off-by: Junio C Hamano <gitster@pobox.com>