builtin/apply: handle parse_binary() failure

In parse_binary() there is:

	forward = parse_binary_hunk(&buffer, &size, &status, &used);
	if (!forward && !status)
		/* there has to be one hunk (forward hunk) */
		return error(_("unrecognized binary patch at line %d"), linenr-1);

so parse_binary() can return -1, because that's what error() returns.

Also parse_binary_hunk() sets "status" to -1 in case of error and
parse_binary() does "if (status) return status;".

In this case parse_chunk() should not add -1 to the patchsize it computes.
It is better for future libification efforts to make it just return -1.

Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin/apply.c

@@ -1863,6 +1863,11 @@ static struct fragment *parse_binary_hunk(char **buf_p,
 	return NULL;
 }
 
+/*
+ * Returns:
+ *   -1 in case of error,
+ *   the length of the parsed binary patch otherwise
+ */
 static int parse_binary(char *buffer, unsigned long size, struct patch *patch)
 {
 	/*
@@ -2008,6 +2013,8 @@ static int parse_chunk(char *buffer, unsigned long size, struct patch *patch)
 			linenr++;
 			used = parse_binary(buffer + hd + llen,
 					    size - hd - llen, patch);
+			if (used < 0)
+				return -1;
 			if (used)
 				patchsize = used + llen;
 			else