builtin/apply: make try_create_file() return -1 on error
To libify `git apply` functionality we have to signal errors to the
caller instead of die()ing.
To do that in a compatible manner with the rest of the error handling
in "builtin/apply.c", try_create_file() should return -1 in case of
error.
Unfortunately try_create_file() currently returns -1 to signal a
recoverable error. To fix that, let's make it return 1 in case of
a recoverable error and -1 in case of an unrecoverable error.
Helped-by: Eric Sunshine <sunshine@sunshineco.com>
Helped-by: Jeff King <peff@peff.net>
Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>