{
BIGNUM *r = NULL;
+ /* This function does not work if
+ * words <= b->dmax && top < words
+ * because BN_dup() does not preserve 'dmax'!
+ * (But bn_dup_expand() is not used anywhere yet.)
+ */
+
if (words > b->dmax)
{
BN_ULONG *a = bn_expand_internal(b, words);