Nearly-finished port of search_required from MRI

gistfile1.java

    // MRI: search_required
    protected char searchRequired(String fname, String[] path) {
        String tmp;
        int extOffset;
        String ext, ftptr;
        char type, ft = 0;
        String[] loadingP;

        path[0] = null;
        extOffset = (ftptr = fname).lastIndexOf('.');
        ext = extOffset == -1 ? null : ftptr.substring(extOffset);
        if (ext != null) {
            if (ext.equals(".rb")) {
                if (isFeatureLoaded(ftptr, ext, true, false, loadingP) != 0) {
                    if (loadingP != null) path[0] = loadingP[0];
                    return 'r';
                }
                if ((tmp = findFileSafe(fname)) != null) {
                    extOffset = (ftptr = tmp).lastIndexOf('.');
                    ext = extOffset == -1 ? null : ftptr.substring(extOffset);
                    if (isFeatureLoaded(ftptr, ext, true, true, loadingP) == 0 || loadingP[0] != null)
                        path[0] = tmp;
                    return 'r';
                }
                return 0;
            }
            else if (ext.equals(".jar")) {
                if (isFeatureLoaded(ftptr, ext, false, false, loadingP) != 0) {
                    if (loadingP[0] != null) path[0] = loadingP[0];
                    return 's';
                }
                tmp = fname.substring(0, extOffset);
                tmp = tmp + ".jar";
                if ((tmp = findFileSafe(tmp)) != null) {
                    extOffset = (ftptr = tmp).lastIndexOf('.');
                    ext = extOffset == -1 ? null : ftptr.substring(extOffset);
                    if (isFeatureLoaded(ftptr, ext, false, true, loadingP) == 0 || loadingP[0] != null)
                        path[0] = tmp;
                    return 's';
                }
            }
            else if (ext.equals(".jar")) {
                if (isFeatureLoaded(ftptr, ext, false, false, loadingP) != 0) {
                    if (loadingP[0] != null) path[0] = loadingP[0];
                    return 's';
                }
                if ((tmp = findFileSafe(fname)) != null) {
                    extOffset = (ftptr = tmp).lastIndexOf('.');
                    ext = extOffset == -1 ? null : ftptr.substring(extOffset);
                    if (isFeatureLoaded(ftptr, ext, false, true, loadingP) == 0 || loadingP[0] != null)
                        path[0] = tmp;
                    return 's';
                }
            }
        }
        else if ((ft = isFeatureLoaded(ftptr, null, false, false, loadingP)) == 'r') {
            if (loadingP[0] != null) path[0] = loadingP[0];
            return 'r';
        }
        String[] tmpP = {fname};
        type = findFileExtSafe(tmpP, loadable_ext);
        switch (type) {
            case 0:
                if (ft != 0)
                    goto statically_linked;
                ftptr = tmp;
                return isFeatureLoaded(ftptr, null, false, true, null);

            default:
                if (ft != 0) {
                    statically_linked:
                    if (loadingP[0] != null) path[0] = loadingP[0];
                    return ft;
                }
            case 1:
                extOffset = (ftptr = tmp).lastIndexOf('.');
                ext = extOffset == -1 ? null : ftptr.substring(extOffset);
                if (isFeatureLoaded(ftptr, ext, (--type) == 0, true, loadingP) != 0 && loadingP[0] == null)
                    break;
            path[0] = tmp;
        }
        if (true) {
            return type != 0 ? 's' : 'r';
        }
    }