find multi-byte comment chars in NUL-terminated strings

peff · gitster · commit 600559b7169c · 2024-03-12T13:28:10.000-07:00
Several parts of the code need to identify lines that begin with the
comment character, and do so with a simple byte equality check. As part
of the transition to handling multi-byte characters, we need to match
all of the bytes. For cases where we are looking in a NUL-terminated
string, we can just use starts_with(), which checks all of the
characters in comment_line_str.

Note that we can drop the "line.len" check in wt-status.c's
read_rebase_todolist(). The starts_with() function handles the case of
an empty haystack buffer (it will always return false for a non-empty
prefix).

Signed-off-by: Jeff King &lt;peff@peff.net&gt;
Signed-off-by: Junio C Hamano &lt;gitster@pobox.com&gt;
diff --git a/add-patch.c b/add-patch.c
@@ -1139,7 +1139,7 @@ static int edit_hunk_manually(struct add_p_state *s, struct hunk *hunk)
 	for (i = 0; i < s->buf.len; ) {
 		size_t next = find_next_line(&s->buf, i);
 
-		if (s->buf.buf[i] != comment_line_char)
+		if (!starts_with(s->buf.buf + i, comment_line_str))
 			strbuf_add(&s->plain, s->buf.buf + i, next - i);
 		i = next;
 	}
diff --git a/sequencer.c b/sequencer.c
@@ -2003,7 +2003,7 @@ static int update_squash_messages(struct repository *r,
 			return error(_("could not read '%s'"),
 				rebase_path_squash_msg());
 
-		eol = buf.buf[0] != comment_line_char ?
+		eol = !starts_with(buf.buf, comment_line_str) ?
 			buf.buf : strchrnul(buf.buf, '\n');
 
 		strbuf_addf(&header, "%s ", comment_line_str);
diff --git a/trailer.c b/trailer.c
@@ -1013,7 +1013,7 @@ static void parse_trailers(struct trailer_info *info,
 	for (i = 0; i < info->trailer_nr; i++) {
 		int separator_pos;
 		char *trailer = info->trailers[i];
-		if (trailer[0] == comment_line_char)
+		if (starts_with(trailer, comment_line_str))
 			continue;
 		separator_pos = find_separator(trailer, separators);
 		if (separator_pos >= 1) {
diff --git a/wt-status.c b/wt-status.c
@@ -1382,7 +1382,7 @@ static int read_rebase_todolist(const char *fname, struct string_list *lines)
 			  git_path("%s", fname));
 	}
 	while (!strbuf_getline_lf(&line, f)) {
-		if (line.len && line.buf[0] == comment_line_char)
+		if (starts_with(line.buf, comment_line_str))
 			continue;
 		strbuf_trim(&line);
 		if (!line.len)

Original file line number	Diff line number	Diff line change
`@@ -1139,7 +1139,7 @@ static int edit_hunk_manually(struct add_p_state s, struct hunk hunk)`
`1139`	`1139`	`for (i = 0; i < s->buf.len; ) {`
`1140`	`1140`	`size_t next = find_next_line(&s->buf, i);`
`1141`	`1141`
`1142`		`- if (s->buf.buf[i] != comment_line_char)`
	`1142`	`+ if (!starts_with(s->buf.buf + i, comment_line_str))`
`1143`	`1143`	`strbuf_add(&s->plain, s->buf.buf + i, next - i);`
`1144`	`1144`	`i = next;`
`1145`	`1145`	`}`
Original file line number	Diff line number	Diff line change
`@@ -1382,7 +1382,7 @@ static int read_rebase_todolist(const char fname, struct string_list lines)`
`1382`	`1382`	`git_path("%s", fname));`
`1383`	`1383`	`}`
`1384`	`1384`	`while (!strbuf_getline_lf(&line, f)) {`
`1385`		`- if (line.len && line.buf[0] == comment_line_char)`
	`1385`	`+ if (starts_with(line.buf, comment_line_str))`
`1386`	`1386`	`continue;`
`1387`	`1387`	`strbuf_trim(&line);`
`1388`	`1388`	`if (!line.len)`