t2004: demonstrate broken relative path printing

checkout-index --temp only properly prints relative paths which are descendants of the current directory. Paths in ancestor or sibling directories (or their children) are often printed in mangled form. For example: mkdir a bbb && >file && >bbb/file && git update-index --add file bbb/file && cd a && git checkout-index --temp ../file ../bbb/file prints: .merge_file_ooblek le .merge_file_igloo0 b/file rather than the correct: .merge_file_ooblek ../file .merge_file_igloo0 ../bbb/file Unfortunately, testing is complicated slightly by relative paths sometimes _appearing_ to be printed correctly, but this is an accident of implementation in which a "correct" copy of the string exists in memory beyond the end of the real string, and that "correct" copy gets printed. This test takes care to avoid the accidentally "correct" behavior by testing with a filename longer than the directory name in which checkout-index is invoked. Signed-off-by: Eric Sunshine <sunshine@sunshineco.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>