static void _6502_anal_update_flags(RAnalOp *op, int flags) {
	/* FIXME: $b9 instead of $b8 to prevent the bug triggered by: A = 0 - 0xff - 1 */
	if (flags & _6502_FLAGS_B) r_strbuf_append (&op->esil, ",$b9,C,=");
	if (flags & _6502_FLAGS_C) r_strbuf_append (&op->esil, ",$c7,C,=");
	if (flags & _6502_FLAGS_Z) r_strbuf_append (&op->esil, ",$z,Z,=");
	if (flags & _6502_FLAGS_N) r_strbuf_append (&op->esil, ",$s,N,=");
}

The product reads data past the end, or before the beginning, of the intended buffer.