#vulnerable code 
                                @Override
    public int newKey(ImmutableBytesWritable key, byte[][] values) {
        int nValues = values.length;
        while (nValues > 0 && (values[nValues-1] == null || values[nValues-1].length == 0)) {
            nValues--;
        }
        int i = 0;
        TrustedByteArrayOutputStream os = new TrustedByteArrayOutputStream(SchemaUtil.estimateKeyLength(this));
        try {
            Integer bucketNum = this.getBucketNum();
            if (bucketNum != null) {
                // Write place holder for salt byte
                i++;
                os.write(QueryConstants.SEPARATOR_BYTE_ARRAY);
            }
            List<PColumn> columns = getPKColumns();
            int nColumns = columns.size();
            PDataType type = null;
            while (i < nValues && i < nColumns) {
                // Separate variable length column values in key with zero byte
                if (type != null && !type.isFixedWidth()) {
                    os.write(SEPARATOR_BYTE);
                }
                PColumn column = columns.get(i);
                type = column.getDataType();
                // This will throw if the value is null and the type doesn't allow null
                byte[] byteValue = values[i++];
                if (byteValue == null) {
                    byteValue = ByteUtil.EMPTY_BYTE_ARRAY;
                }
                // An empty byte array return value means null. Do this,
                // since a type may have muliple representations of null.
                // For example, VARCHAR treats both null and an empty string
                // as null. This way we don't need to leak that part of the
                // implementation outside of PDataType by checking the value
                // here.
                if (byteValue.length == 0 && !column.isNullable()) { 
                    throw new ConstraintViolationException(name.getString() + "." + column.getName().getString() + " may not be null");
                }
                Integer	maxLength = column.getMaxLength();
                if (maxLength != null && type.isFixedWidth() && byteValue.length <= maxLength) {
                    byteValue = StringUtil.padChar(byteValue, maxLength);
                } else if (maxLength != null && byteValue.length > maxLength) {
                    throw new ConstraintViolationException(name.getString() + "." + column.getName().getString() + " may not exceed " + maxLength + " bytes (" + SchemaUtil.toString(type, byteValue) + ")");
                }
                os.write(byteValue, 0, byteValue.length);
            }
            // If some non null pk values aren't set, then throw
            if (i < nColumns) {
                PColumn column = columns.get(i);
                type = column.getDataType();
                if (type.isFixedWidth() || !column.isNullable()) {
                    throw new ConstraintViolationException(name.getString() + "." + column.getName().getString() + " may not be null");
                }
            }
            byte[] buf = os.getBuffer();
            int size = os.size();
            if (bucketNum != null) {
                buf[0] = SaltingUtil.getSaltingByte(buf, 1, size-1, bucketNum);
            }
            key.set(buf,0,size);
            return i;
        } finally {
            try {
                os.close();
            } catch (IOException e) {
                throw new RuntimeException(e); // Impossible
            }
        }
    } 
                            #location 59 
                            #vulnerability type NULL_DEREFERENCE
#fixed code
                                @Override
    public int newKey(ImmutableBytesWritable key, byte[][] values) {
        int nValues = values.length;
        while (nValues > 0 && (values[nValues-1] == null || values[nValues-1].length == 0)) {
            nValues--;
        }
        int i = 0;
        TrustedByteArrayOutputStream os = new TrustedByteArrayOutputStream(SchemaUtil.estimateKeyLength(this));
        try {
            Integer bucketNum = this.getBucketNum();
            if (bucketNum != null) {
                // Write place holder for salt byte
                i++;
                os.write(QueryConstants.SEPARATOR_BYTE_ARRAY);
            }
            List<PColumn> columns = getPKColumns();
            int nColumns = columns.size();
            PDataType type = null;
            while (i < nValues && i < nColumns) {
                // Separate variable length column values in key with zero byte
                if (type != null && !type.isFixedWidth()) {
                    os.write(SEPARATOR_BYTE);
                }
                PColumn column = columns.get(i);
                type = column.getDataType();
                // This will throw if the value is null and the type doesn't allow null
                byte[] byteValue = values[i++];
                if (byteValue == null) {
                    byteValue = ByteUtil.EMPTY_BYTE_ARRAY;
                }
                // An empty byte array return value means null. Do this,
                // since a type may have muliple representations of null.
                // For example, VARCHAR treats both null and an empty string
                // as null. This way we don't need to leak that part of the
                // implementation outside of PDataType by checking the value
                // here.
                if (byteValue.length == 0 && !column.isNullable()) { 
                    throw new ConstraintViolationException(name.getString() + "." + column.getName().getString() + " may not be null");
                }
                Integer	maxLength = column.getMaxLength();
                if (maxLength != null && type.isFixedWidth() && byteValue.length <= maxLength) {
                    byteValue = StringUtil.padChar(byteValue, maxLength);
                } else if (maxLength != null && byteValue.length > maxLength) {
                    throw new ConstraintViolationException(name.getString() + "." + column.getName().getString() + " may not exceed " + maxLength + " bytes (" + SchemaUtil.toString(type, byteValue) + ")");
                }
                os.write(byteValue, 0, byteValue.length);
            }
            // If some non null pk values aren't set, then throw
            if (i < nColumns) {
                PColumn column = columns.get(i);
                type = column.getDataType();
                if (type.isFixedWidth() || !column.isNullable()) {
                    throw new ConstraintViolationException(name.getString() + "." + column.getName().getString() + " may not be null");
                }
            }
            if (nValues == 0) { 
                throw new ConstraintViolationException("Primary key may not be null ("+ name.getString() + ")");
            }
            byte[] buf = os.getBuffer();
            int size = os.size();
            if (bucketNum != null) {
                buf[0] = SaltingUtil.getSaltingByte(buf, 1, size-1, bucketNum);
            }
            key.set(buf,0,size);
            return i;
        } finally {
            try {
                os.close();
            } catch (IOException e) {
                throw new RuntimeException(e); // Impossible
            }
        }
    }