+struct charset_sort_data
+{
+ Lisp_Object charset;
+ int id;
+ int priority;
+};
+
+static int
+charset_compare (const void *d1, const void *d2)
+{
+ const struct charset_sort_data *data1 = d1, *data2 = d2;
+ return (data1->priority - data2->priority);
+}
+
+DEFUN ("sort-charsets", Fsort_charsets, Ssort_charsets, 1, 1, 0,
+ doc: /* Sort charset list CHARSETS by a priority of each charset.
+Return the sorted list. CHARSETS is modified by side effects.
+See also `charset-priority-list' and `set-charset-priority'. */)
+ (Lisp_Object charsets)
+{
+ Lisp_Object len = Flength (charsets);
+ int n = XFASTINT (len), i, j, done;
+ Lisp_Object tail, elt, attrs;
+ struct charset_sort_data *sort_data;
+ int id, min_id, max_id;
+ USE_SAFE_ALLOCA;
+
+ if (n == 0)
+ return Qnil;
+ SAFE_ALLOCA (sort_data, struct charset_sort_data *, sizeof (*sort_data) * n);
+ for (tail = charsets, i = 0; CONSP (tail); tail = XCDR (tail), i++)
+ {
+ elt = XCAR (tail);
+ CHECK_CHARSET_GET_ATTR (elt, attrs);
+ sort_data[i].charset = elt;
+ sort_data[i].id = id = XINT (CHARSET_ATTR_ID (attrs));
+ if (i == 0)
+ min_id = max_id = id;
+ else if (id < min_id)
+ min_id = id;
+ else if (id > max_id)
+ max_id = id;
+ }
+ for (done = 0, tail = Vcharset_ordered_list, i = 0;
+ done < n && CONSP (tail); tail = XCDR (tail), i++)
+ {
+ elt = XCAR (tail);
+ id = XFASTINT (elt);
+ if (id >= min_id && id <= max_id)
+ for (j = 0; j < n; j++)
+ if (sort_data[j].id == id)
+ {
+ sort_data[j].priority = i;
+ done++;
+ }
+ }
+ qsort (sort_data, n, sizeof *sort_data, charset_compare);
+ for (i = 0, tail = charsets; CONSP (tail); tail = XCDR (tail), i++)
+ XSETCAR (tail, sort_data[i].charset);
+ SAFE_FREE ();
+ return charsets;
+}
+