+
+static int ends_rfc2822_footer(struct strbuf *sb, int ignore_footer)
+{
+ int ch;
+ int hit = 0;
+ int i, j, k;
+ int len = sb->len - ignore_footer;
+ int first = 1;
+ const char *buf = sb->buf;
+
+ for (i = len - 1; i > 0; i--) {
+ if (hit && buf[i] == '\n')
+ break;
+ hit = (buf[i] == '\n');
+ }
+
+ while (i < len - 1 && buf[i] == '\n')
+ i++;
+
+ for (; i < len; i = k) {
+ for (k = i; k < len && buf[k] != '\n'; k++)
+ ; /* do nothing */
+ k++;
+
+ if ((buf[k] == ' ' || buf[k] == '\t') && !first)
+ continue;
+
+ first = 0;
+
+ for (j = 0; i + j < len; j++) {
+ ch = buf[i + j];
+ if (ch == ':')
+ break;
+ if (isalnum(ch) ||
+ (ch == '-'))
+ continue;
+ return 0;
+ }
+ }
+ return 1;
+}
+
+void append_signoff(struct strbuf *msgbuf, int ignore_footer)
+{
+ struct strbuf sob = STRBUF_INIT;
+ int i;
+
+ strbuf_addstr(&sob, sign_off_header);
+ strbuf_addstr(&sob, fmt_name(getenv("GIT_COMMITTER_NAME"),
+ getenv("GIT_COMMITTER_EMAIL")));
+ strbuf_addch(&sob, '\n');
+ for (i = msgbuf->len - 1 - ignore_footer; i > 0 && msgbuf->buf[i - 1] != '\n'; i--)
+ ; /* do nothing */
+ if (prefixcmp(msgbuf->buf + i, sob.buf)) {
+ if (!i || !ends_rfc2822_footer(msgbuf, ignore_footer))
+ strbuf_splice(msgbuf, msgbuf->len - ignore_footer, 0, "\n", 1);
+ strbuf_splice(msgbuf, msgbuf->len - ignore_footer, 0, sob.buf, sob.len);
+ }
+ strbuf_release(&sob);
+}