+static int is_rfc2822_line(const char *buf, int len)
+{
+ int i;
+
+ for (i = 0; i < len; i++) {
+ int ch = buf[i];
+ if (ch == ':')
+ return 1;
+ if (!isalnum(ch) && ch != '-')
+ break;
+ }
+
+ return 0;
+}
+
+static int is_cherry_picked_from_line(const char *buf, int len)
+{
+ /*
+ * We only care that it looks roughly like (cherry picked from ...)
+ */
+ return len > strlen(cherry_picked_prefix) + 1 &&
+ !prefixcmp(buf, cherry_picked_prefix) && buf[len - 1] == ')';
+}
+
+static int has_conforming_footer(struct strbuf *sb, int ignore_footer)
+{
+ char prev;
+ int i, k;
+ int len = sb->len - ignore_footer;
+ const char *buf = sb->buf;
+
+ /* footer must end with newline */
+ if (!len || buf[len - 1] != '\n')
+ return 0;
+
+ prev = '\0';
+ for (i = len - 1; i > 0; i--) {
+ char ch = buf[i];
+ if (prev == '\n' && ch == '\n') /* paragraph break */
+ break;
+ prev = ch;
+ }
+
+ /* require at least one blank line */
+ if (prev != '\n' || buf[i] != '\n')
+ return 0;
+
+ /* advance to start of last paragraph */
+ 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 (!is_rfc2822_line(buf + i, k - i - 1) &&
+ !is_cherry_picked_from_line(buf + i, k - i - 1))
+ return 0;
+ }
+ return 1;
+}
+