setDelimiterSpecs() accumulates markLength instead of recalculating

[elharo]

In src/main/java/org/apache/maven/shared/filtering/MultiDelimiterInterpolatorFilterReaderLineEnding.java, lines 133–141:

public AbstractFilterReaderLineEnding setDelimiterSpecs(Set<String> specs) {
    delimiters.clear();
    for (String spec : specs) {
        delimiters.add(DelimiterSpecification.parse(spec));
        markLength += spec.length() * 2;
    }
    return this;
}

markLength is accumulated on top of the current value rather than recalculated from base (255 + escapeString.length). If setDelimiterSpecs is called multiple times, markLength grows unbounded. Currently this is safe only because setEscapeString() always follows in Wrapper.getReader() and calls calculateMarkLength() which resets the value. However, this inter-call dependency is fragile and undocumented.