The top-level mailinfo() would instead punt when the code in the
deeper part of the callchain detects an unrecoverable error in the
input.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Move the bulk of the code from builtin/mailinfo.c to mailinfo.c
so that new callers can start calling mailinfo() directly.
Note that a few calls to exit() and die() need to be cleaned up
for the API to be truly useful, which will come in later steps.
Signed-off-by: Junio C Hamano <gitster@pobox.com>