pErrCode not set in ACN decoder for OCTET STRING with external size

[Rafał Babski]

ASN file:

TEST-DATAVIEW DEFINITIONS ::=
BEGIN
	MyInteger ::= INTEGER (0..10)
    MyData ::= OCTET STRING (SIZE(0..4))
    MyPacket ::= SEQUENCE {
		bytes MyData
	}
END

ACN file:

TEST-DATAVIEW DEFINITIONS ::= BEGIN
    MyData []
	MyPacket [] {
	    len MyInteger [size 8, encoding pos-int],
		bytes [size len]
	}
END

Asn1scc is invoked using command line:

asn1scc -c --type-prefix asn1Scc -ACN test.asn test.acn

Revelant content of generated test.c file (some comments added manually):

flag asn1SccMyPacket_ACN_Decode(asn1SccMyPacket* pVal, BitStream* pBitStrm, int* pErrCode)
{
    flag ret = TRUE;
	*pErrCode = 0;

	asn1SccUint MyPacket_len;

	/*Decode MyPacket_len */
	ret = Acn_Dec_Int_PositiveInteger_ConstSize_8(pBitStrm, (&(MyPacket_len)));
	*pErrCode = ret ? 0 : ERR_ACN_DECODE_MYPACKET_LEN;
	if (ret) {
	    /*Decode bytes */
	    ret = ((MyPacket_len<=4)); // pErrCode is not set here, example: MyPacket_len is 8
	    if (ret) {
	        pVal->bytes.nCount = (int)MyPacket_len;
	        ret = BitStream_DecodeOctetString_no_length(pBitStrm, pVal->bytes.arr, pVal->bytes.nCount);
            // pErrCode is not set here, example: MyPacket_len is 4 and bit stream has only 2 bytes left
	    }
	}   /*COVERAGE_IGNORE*/

    return ret && asn1SccMyPacket_IsConstraintValid(pVal, pErrCode);
}

The issue:

• The error code is not set when decoded length is outside allowed range, in the example the length can be from 0 to 4, what is validated, but when it is invalid, the error code is not set. See the line with comment pErrCode is not set here, example: MyPacket_len is 8
• The error code is not set when bit stream contains too few bytes than expected, i.e. the total bit stream is 3 octets and the first octet contains length with value 4 (which is valid), then decoder expects 4 more octets, but only two are available. In such case decoder fails, but no error code is set. See the line above comment pErrCode is not set here, example: MyPacket_len is 4 and bit stream has only 2 bytes left

Expected behaviour:

In both cases the error code shall be set to non zero value.

[usr3-1415]

fixed