+static gboolean
+gtk_text_iter_forward_search_insensitive (const GtkTextIter *iter,
+ const gchar *str,
+ GtkTextIter *match_start,
+ GtkTextIter *match_end)
+{
+ GtkTextIter end_iter;
+ gchar *str_casefold;
+ gint str_chars_n;
+ gchar *range_text;
+ gchar *range_casefold;
+ gint offset;
+ gint range_chars_n;
+ gboolean result = FALSE;
+
+ if (str == NULL)
+ return TRUE;
+
+ /* get end iter */
+ end_iter = *iter;
+ gtk_text_iter_forward_to_end (&end_iter);
+
+ str_casefold = g_utf8_casefold (str, -1);
+ str_chars_n = strlen (str);
+
+ range_text = gtk_text_iter_get_visible_text (iter, &end_iter);
+ range_casefold = g_utf8_casefold (range_text, -1);
+ range_chars_n = strlen (range_casefold);
+
+ if (range_chars_n < str_chars_n) {
+ g_free (str_casefold);
+ g_free (range_text);
+ g_free (range_casefold);
+ return FALSE;
+ }
+
+ for (offset = 0; offset <= range_chars_n - str_chars_n; offset++) {
+ gchar *range_subtext = g_strndup (range_casefold + offset, str_chars_n);
+ if (!g_utf8_collate (range_subtext, str_casefold)) {
+ gchar *found_text = g_strndup (range_text + offset, str_chars_n);
+ result = TRUE;
+ gtk_text_iter_forward_search (iter, found_text, GTK_TEXT_SEARCH_VISIBLE_ONLY|GTK_TEXT_SEARCH_TEXT_ONLY,
+ match_start, match_end, NULL);
+ g_free (found_text);
+ }
+ g_free (range_subtext);
+ if (result)
+ break;
+ }
+ g_free (str_casefold);
+ g_free (range_text);
+ g_free (range_casefold);
+
+ return result;
+}
+
+