private static SimpleConfigOrigin mergeTwo()

in scripts/src/main/java/com/gu/typesafe/config/impl/SimpleConfigOrigin.java [229:308]
61 lines of code
14 McCabe index (conditional complexity)

    private static SimpleConfigOrigin mergeTwo(SimpleConfigOrigin a, SimpleConfigOrigin b) {
        String mergedDesc;
        int mergedStartLine;
        int mergedEndLine;
        List<String> mergedComments;

        OriginType mergedType;
        if (a.originType == b.originType) {
            mergedType = a.originType;
        } else {
            mergedType = OriginType.GENERIC;
        }

        // first use the "description" field which has no line numbers
        // cluttering it.
        String aDesc = a.description;
        String bDesc = b.description;
        if (aDesc.startsWith(MERGE_OF_PREFIX))
            aDesc = aDesc.substring(MERGE_OF_PREFIX.length());
        if (bDesc.startsWith(MERGE_OF_PREFIX))
            bDesc = bDesc.substring(MERGE_OF_PREFIX.length());

        if (aDesc.equals(bDesc)) {
            mergedDesc = aDesc;

            if (a.lineNumber < 0)
                mergedStartLine = b.lineNumber;
            else if (b.lineNumber < 0)
                mergedStartLine = a.lineNumber;
            else
                mergedStartLine = Math.min(a.lineNumber, b.lineNumber);

            mergedEndLine = Math.max(a.endLineNumber, b.endLineNumber);
        } else {
            // this whole merge song-and-dance was intended to avoid this case
            // whenever possible, but we've lost. Now we have to lose some
            // structured information and cram into a string.

            // description() method includes line numbers, so use it instead
            // of description field.
            String aFull = a.description();
            String bFull = b.description();
            if (aFull.startsWith(MERGE_OF_PREFIX))
                aFull = aFull.substring(MERGE_OF_PREFIX.length());
            if (bFull.startsWith(MERGE_OF_PREFIX))
                bFull = bFull.substring(MERGE_OF_PREFIX.length());

            mergedDesc = MERGE_OF_PREFIX + aFull + "," + bFull;

            mergedStartLine = -1;
            mergedEndLine = -1;
        }

        String mergedURL;
        if (ConfigImplUtil.equalsHandlingNull(a.urlOrNull, b.urlOrNull)) {
            mergedURL = a.urlOrNull;
        } else {
            mergedURL = null;
        }

        String mergedResource;
        if (ConfigImplUtil.equalsHandlingNull(a.resourceOrNull, b.resourceOrNull)) {
            mergedResource = a.resourceOrNull;
        } else {
            mergedResource = null;
        }

        if (ConfigImplUtil.equalsHandlingNull(a.commentsOrNull, b.commentsOrNull)) {
            mergedComments = a.commentsOrNull;
        } else {
            mergedComments = new ArrayList<String>();
            if (a.commentsOrNull != null)
                mergedComments.addAll(a.commentsOrNull);
            if (b.commentsOrNull != null)
                mergedComments.addAll(b.commentsOrNull);
        }

        return new SimpleConfigOrigin(mergedDesc, mergedStartLine, mergedEndLine, mergedType, mergedURL,
                mergedResource, mergedComments);
    }