The test passed for the wrong reason: If the script given to --msg-filter
fails, it is expected that git-filter-branch aborts. But the test forgot
to tell the branch name to rewrite, and so git-filter-branch failed due to
incorrect usage.
Signed-off-by: Johannes Sixt <johannes.sixt@telecom.at> Signed-off-by: Junio C Hamano <gitster@pobox.com>