parse-options: add parse_options_concat() to concat options

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

parse-options.c

@@ -659,3 +659,18 @@ int parse_opt_tertiary(const struct option *opt, const char *arg, int unset)
 	*target = unset ? 2 : 1;
 	return 0;
 }
+
+int parse_options_concat(struct option *dst, size_t dst_size, struct option *src)
+{
+	int i, j;
+
+	for (i = 0; i < dst_size; i++)
+		if (dst[i].type == OPTION_END)
+			break;
+	for (j = 0; i < dst_size; i++, j++) {
+		dst[i] = src[j];
+		if (src[j].type == OPTION_END)
+			return 0;
+	}
+	return -1;
+}

parse-options.h

@@ -187,6 +187,7 @@ extern int parse_options_step(struct parse_opt_ctx_t *ctx,
 
 extern int parse_options_end(struct parse_opt_ctx_t *ctx);
 
+extern int parse_options_concat(struct option *dst, size_t, struct option *src);
 
 /*----- some often used options -----*/
 extern int parse_opt_abbrev_cb(const struct option *, const char *, int);