mailmap: simplify map_user() interface

Simplify map_user(), mostly to avoid copies of string buffers. It
also simplifies caller functions.

map_user() directly receive pointers and length from the commit buffer
as mail and name. If mapping of the user and mail can be done, the
pointer is updated to a new location. Lengths are also updated if
necessary.

The caller of map_user() can then copy the new email and name if
necessary.

Signed-off-by: Antoine Pelisse <apelisse@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 13 insertions, 22 deletions

diff --git a/pretty.c b/pretty.c
index 350d1df3f..dffcadec9 100644
--- a/pretty.c
+++ b/pretty.c
@@ -593,7 +593,8 @@ char *logmsg_reencode(const struct commit *commit,
 	return out;
 }
 
-static int mailmap_name(char *email, int email_len, char *name, int name_len)
+static int mailmap_name(const char **email, size_t *email_len,
+			const char **name, size_t *name_len)
 {
 	static struct string_list *mail_map;
 	if (!mail_map) {
@@ -610,36 +611,26 @@ static size_t format_person_part(struct strbuf *sb, char part,
 	const int placeholder_len = 2;
 	int tz;
 	unsigned long date = 0;
-	char person_name[1024];
-	char person_mail[1024];
 	struct ident_split s;
-	const char *name_start, *name_end, *mail_start, *mail_end;
+	const char *name, *mail;
+	size_t maillen, namelen;
 
 	if (split_ident_line(&s, msg, len) < 0)
 		goto skip;
 
-	name_start = s.name_begin;
-	name_end = s.name_end;
-	mail_start = s.mail_begin;
-	mail_end = s.mail_end;
-
-	if (part == 'N' || part == 'E') { /* mailmap lookup */
-		snprintf(person_name, sizeof(person_name), "%.*s",
-			 (int)(name_end - name_start), name_start);
-		snprintf(person_mail, sizeof(person_mail), "%.*s",
-			 (int)(mail_end - mail_start), mail_start);
-		mailmap_name(person_mail, sizeof(person_mail), person_name, sizeof(person_name));
-		name_start = person_name;
-		name_end = name_start + strlen(person_name);
-		mail_start = person_mail;
-		mail_end = mail_start +  strlen(person_mail);
-	}
+	name = s.name_begin;
+	namelen = s.name_end - s.name_begin;
+	mail = s.mail_begin;
+	maillen = s.mail_end - s.mail_begin;
+
+	if (part == 'N' || part == 'E') /* mailmap lookup */
+		mailmap_name(&mail, &maillen, &name, &namelen);
 	if (part == 'n' || part == 'N') {	/* name */
-		strbuf_add(sb, name_start, name_end-name_start);
+		strbuf_add(sb, name, namelen);
 		return placeholder_len;
 	}
 	if (part == 'e' || part == 'E') {	/* email */
-		strbuf_add(sb, mail_start, mail_end-mail_start);
+		strbuf_add(sb, mail, maillen);
 		return placeholder_len;
 	}