trailer: support multiline titlecc/trailers-corner-case-fix

We currently ignore the first line passed to `git interpret-trailers`,
when looking for the beginning of the trailers.

Unfortunately this does not work well when a commit is created with a
line break in the title, using for example the following command:

git commit -m 'place of
code: change we made'

That's why instead of ignoring only the first line, it is better to
ignore the first paragraph.

Signed-off-by: Christian Couder <christian.couder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 11 insertions, 4 deletions

diff --git a/trailer.c b/trailer.c
index a92ba53fa5..5ec5f9ddc1 100644
--- a/trailer.c
+++ b/trailer.c
@@ -743,15 +743,22 @@ static int find_patch_start(struct strbuf **lines, int count)
  */
 static int find_trailer_start(struct strbuf **lines, int count)
 {
-	int start, only_spaces = 1;
+	int start, end_of_title, only_spaces = 1;
+
+	/* The first paragraph is the title and cannot be trailers */
+	for (start = 0; start < count; start++) {
+		if (lines[start]->buf[0] == comment_line_char)
+			continue;
+		if (contains_only_spaces(lines[start]->buf))
+			break;
+	}
+	end_of_title = start;
 
 	/*
 	 * Get the start of the trailers by looking starting from the end
 	 * for a line with only spaces before lines with one separator.
-	 * The first line must not be analyzed as the others as it
-	 * should be either the message title or a blank line.
 	 */
-	for (start = count - 1; start >= 1; start--) {
+	for (start = count - 1; start >= end_of_title; start--) {
 		if (lines[start]->buf[0] == comment_line_char)
 			continue;
 		if (contains_only_spaces(lines[start]->buf)) {