shortlog: handle multi-line subjects like log --pretty=oneline et. al. do

The commit message parser of git shortlog used to treat only the first
non-empty line of the commit message as the subject.  Other log commands
(e.g. --pretty=oneline) show the whole first paragraph instead (unwrapped
into a single line).

For consistency, this patch borrows format_subject() from pretty.c to
make shortlog do the same.

Signed-off-by: Rene Scharfe <rene.scharfe@lsrfire.ath.cx>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin-shortlog.c

@@ -29,6 +29,9 @@ static int compare_by_number(const void *a1, const void *a2)
 		return -1;
 }
 
+const char *format_subject(struct strbuf *sb, const char *msg,
+			   const char *line_separator);
+
 static void insert_one_record(struct shortlog *log,
 			      const char *author,
 			      const char *oneline)
@@ -41,6 +44,7 @@ static void insert_one_record(struct shortlog *log,
 	size_t len;
 	const char *eol;
 	const char *boemail, *eoemail;
+	struct strbuf subject = STRBUF_INIT;
 
 	boemail = strchr(author, '<');
 	if (!boemail)
@@ -89,9 +93,8 @@ static void insert_one_record(struct shortlog *log,
 	while (*oneline && isspace(*oneline) && *oneline != '\n')
 		oneline++;
 	len = eol - oneline;
-	while (len && isspace(oneline[len-1]))
+	format_subject(&subject, oneline, " ");
-		len--;
+	buffer = strbuf_detach(&subject, NULL);
-	buffer = xmemdupz(oneline, len);
 
 	if (dot3) {
 		int dot3len = strlen(dot3);

pretty.c

@@ -486,8 +486,8 @@ static void parse_commit_header(struct format_commit_context *context)
 	context->commit_header_parsed = 1;
 }
 
-static const char *format_subject(struct strbuf *sb, const char *msg,
+const char *format_subject(struct strbuf *sb, const char *msg,
-				  const char *line_separator)
+			   const char *line_separator)
 {
 	int first = 1;