Add test case for truncated packets

Truncated packets have HF0_TRUNC flag set and their size is greater than
OV_MAX_PACKET_SIZE. Current gateware captures packets up to 1027 bytes
long and therefore the truncated packet can only be observed when either
there is a babble on the bus or there is capture buffer overflow (but
not all capture overflows result in truncated packets because it all
depends on the original traffic and what data was dropped).

test/decoder.c

@@ -5,7 +5,7 @@
 
 union {
 	struct ov_packet packet;
-	uint8_t data[1024];
+	uint8_t data[sizeof(struct ov_packet) + OV_MAX_PACKET_SIZE];
 } p;
 
 struct decoder_ops ops = {
@@ -80,6 +80,19 @@ START_TEST (test_packet_decoder5) {
 }
 END_TEST
 
+START_TEST (test_packet_decoder_truncated) {
+	char inp[5 + OV_MAX_PACKET_SIZE + 1] = {
+		0xa0, OV_FLAGS_HF0_TRUNC,
+		(OV_MAX_PACKET_SIZE + 1) & 0xff, ((OV_MAX_PACKET_SIZE + 1) >> 8) & 0x1f,
+	};
+	ck_assert_int_eq(packet_decoder_proc(&pd, inp, sizeof(inp)), sizeof(inp) - 1);
+	ck_assert_int_eq(pd.state, NEED_PACKET_MAGIC);
+	ck_assert_int_eq(p.packet.size, OV_MAX_PACKET_SIZE+1);
+	ck_assert_int_eq(ov_packet_captured_size(&p.packet), OV_MAX_PACKET_SIZE);
+	ck_assert_int_eq(memcmp(p.packet.data, inp+5, OV_MAX_PACKET_SIZE), 0);
+}
+END_TEST
+
 START_TEST (test_frame_decoder1) {
 	char inp[] = {
 		0xd0, 0x1f, 0xa0, 0x00, 0x00, 0x03, 0x00, 0xba,
@@ -149,6 +162,7 @@ Suite* range_suite(void) {
 	tcase_add_test(tc_packet, test_packet_decoder3);
 	tcase_add_test(tc_packet, test_packet_decoder4);
 	tcase_add_test(tc_packet, test_packet_decoder5);
+	tcase_add_test(tc_packet, test_packet_decoder_truncated);
 	suite_add_tcase(s, tc_packet);
 
 	tc_frame = tcase_create("Frame");