#fixed code
                                public ComparisonResult evaluate(Comparison comparison, ComparisonResult outcome) {
        Comparison.Detail controlDetails = comparison.getControlDetails();
        Node controlTarget = controlDetails.getTarget();
        Comparison.Detail testDetails = comparison.getTestDetails();
        Node testTarget = testDetails.getTarget();

        // comparing textual content of elements
        if (comparison.getType() == ComparisonType.TEXT_VALUE) {
            return evaluateConsideringPlaceholders((String) controlDetails.getValue(),
                (String) testDetails.getValue(), outcome);

        // two versions of "test document has no text-like node but control document has"
        } else if (comparison.getType() == ComparisonType.CHILD_NODELIST_LENGTH &&
                Integer.valueOf(1).equals(controlDetails.getValue()) &&
                Integer.valueOf(0).equals(testDetails.getValue()) &&
                isTextLikeNode(controlTarget.getFirstChild().getNodeType())) {
            String controlNodeChildValue = controlTarget.getFirstChild().getNodeValue();
            return evaluateConsideringPlaceholders(controlNodeChildValue, null, outcome);

        } else if (comparison.getType() == ComparisonType.CHILD_LOOKUP && controlTarget != null &&
                isTextLikeNode(controlTarget.getNodeType())) {
            String controlNodeValue = controlTarget.getNodeValue();
            return evaluateConsideringPlaceholders(controlNodeValue, null, outcome);

        // may be comparing TEXT to CDATA
        } else if (comparison.getType() == ComparisonType.NODE_TYPE
                   && isTextLikeNode(controlTarget.getNodeType())
                   && isTextLikeNode(testTarget.getNodeType())) {
            return evaluateConsideringPlaceholders(controlTarget.getNodeValue(), testTarget.getNodeValue(), outcome);

        // comparing textual content of attributes
        } else if (comparison.getType() == ComparisonType.ATTR_VALUE) {
            return evaluateConsideringPlaceholders((String) controlDetails.getValue(),
                (String) testDetails.getValue(), outcome);

        // two versions of "test document has no attribute but control document has"
        } else if (comparison.getType() == ComparisonType.ELEMENT_NUM_ATTRIBUTES) {
            Map<QName, String> controlAttrs = Nodes.getAttributes(controlTarget);
            Map<QName, String> testAttrs = Nodes.getAttributes(testTarget);

            int cAttrsMatched = 0;
            for (Map.Entry<QName, String> cAttr : controlAttrs.entrySet()) {
                String testValue = testAttrs.get(cAttr.getKey());
                if (testValue == null) {
                    ComparisonResult o = evaluateConsideringPlaceholders(cAttr.getValue(), null, outcome);
                    if (o != ComparisonResult.EQUAL) {
                        return outcome;
                    }
                } else {
                    cAttrsMatched++;
                }
            }
            if (cAttrsMatched != testAttrs.size()) {
                // there are unmatched test attributes
                return outcome;
            }
            return ComparisonResult.EQUAL;

        } else if (comparison.getType() == ComparisonType.ATTR_NAME_LOOKUP && controlTarget != null
            && controlDetails.getValue() != null) {
            String controlAttrValue = Nodes.getAttributes(controlTarget).get((QName) controlDetails.getValue());
            return evaluateConsideringPlaceholders(controlAttrValue, null, outcome);

        // default, don't apply any placeholders at all
        } else {
            return outcome;
        }
    }
#vulnerable code 
                                public ComparisonResult evaluate(Comparison comparison, ComparisonResult outcome) {
        Comparison.Detail controlDetails = comparison.getControlDetails();
        Node controlTarget = controlDetails.getTarget();
        Comparison.Detail testDetails = comparison.getTestDetails();
        Node testTarget = testDetails.getTarget();

        // comparing textual content of elements
        if (comparison.getType() == ComparisonType.TEXT_VALUE) {
            return evaluateConsideringPlaceholders((String) controlDetails.getValue(),
                (String) testDetails.getValue(), outcome);

        // two possible cases of "test document has no text-like node but control document has"
        } else if (comparison.getType() == ComparisonType.CHILD_NODELIST_LENGTH &&
                Integer.valueOf(1).equals(controlDetails.getValue()) &&
                Integer.valueOf(0).equals(testDetails.getValue()) &&
                isTextLikeNode(controlTarget.getFirstChild().getNodeType())) {
            String controlNodeChildValue = controlTarget.getFirstChild().getNodeValue();
            return evaluateConsideringPlaceholders(controlNodeChildValue, null, outcome);

        } else if (comparison.getType() == ComparisonType.CHILD_LOOKUP && controlTarget != null &&
                isTextLikeNode(controlTarget.getNodeType())) {
            String controlNodeValue = controlTarget.getNodeValue();
            return evaluateConsideringPlaceholders(controlNodeValue, null, outcome);

        // may be comparing TEXT to CDATA
        } else if (comparison.getType() == ComparisonType.NODE_TYPE
                   && isTextLikeNode(controlTarget.getNodeType())
                   && isTextLikeNode(testTarget.getNodeType())) {
            return evaluateConsideringPlaceholders(controlTarget.getNodeValue(), testTarget.getNodeValue(), outcome);

        // default, don't apply any placeholders at all
        } else {
            return outcome;
        }
    } 
                            #location 27 
                            #vulnerability type NULL_DEREFERENCE