+static const char *
+skip_re_in_subject (const char *subject)
+{
+ const char *s = subject;
+
+ while (*s) {
+ while (*s && isspace (*s))
+ s++;
+ if (strncasecmp (s, "re:", 3) == 0)
+ s += 3;
+ else
+ break;
+ }
+
+ return s;
+}
+
+/* Add a term for each message-id in the References header of the
+ * message. */
+static void
+add_terms_references (Xapian::Document doc,
+ GMimeMessage *message)
+{
+ const char *refs, *end, *next;
+ char *term;
+
+ refs = g_mime_object_get_header (GMIME_OBJECT (message), "references");
+
+ if (refs == NULL)
+ return;
+
+ while (*refs) {
+ while (*refs && isspace (*refs))
+ refs++;
+ if (*refs == '<')
+ refs++;
+ end = refs;
+ while (*end && !isspace (*end))
+ end++;
+ next = end;
+ end--;
+ if (end > refs && *end == '>')
+ end--;
+ if (end > refs) {
+ term = g_strndup (refs, end - refs + 1);
+ add_term (doc, "ref", term);
+ g_free (term);
+ }
+ refs = next;
+ }
+}
+