+static int rest_is_empty(const struct strbuf *sb, int start)
+{
+ int i, eol;
+ const char *nl;
+
+ /* Check if the rest is just whitespace and Signed-off-by's. */
+ for (i = start; i < sb->len; i++) {
+ nl = memchr(sb->buf + i, '\n', sb->len - i);
+ if (nl)
+ eol = nl - sb->buf;
+ else
+ eol = sb->len;
+
+ if (strlen(sign_off_header) <= eol - i &&
+ starts_with(sb->buf + i, sign_off_header)) {
+ i = eol;
+ continue;
+ }
+ while (i < eol)
+ if (!isspace(sb->buf[i++]))
+ return 0;
+ }
+
+ return 1;
+}
+
+/*
+ * Find out if the message in the strbuf contains only whitespace and
+ * Signed-off-by lines.
+ */
+int message_is_empty(const struct strbuf *sb,
+ enum commit_msg_cleanup_mode cleanup_mode)
+{
+ if (cleanup_mode == COMMIT_MSG_CLEANUP_NONE && sb->len)
+ return 0;
+ return rest_is_empty(sb, 0);
+}
+
+/*
+ * See if the user edited the message in the editor or left what
+ * was in the template intact
+ */
+int template_untouched(const struct strbuf *sb, const char *template_file,
+ enum commit_msg_cleanup_mode cleanup_mode)
+{
+ struct strbuf tmpl = STRBUF_INIT;
+ const char *start;
+
+ if (cleanup_mode == COMMIT_MSG_CLEANUP_NONE && sb->len)
+ return 0;
+
+ if (!template_file || strbuf_read_file(&tmpl, template_file, 0) <= 0)
+ return 0;
+
+ strbuf_stripspace(&tmpl, cleanup_mode == COMMIT_MSG_CLEANUP_ALL);
+ if (!skip_prefix(sb->buf, tmpl.buf, &start))
+ start = sb->buf;
+ strbuf_release(&tmpl);
+ return rest_is_empty(sb, start - sb->buf);
+}
+