TermOrdsIterator#lookup throws ArrayIndexOutOfBoundsException [LUCENE-3377]

[asfimport]

TermOrdsIterator's lookup method can throw an ArrayIndexOutOfBoundsException if reuse argument is reused acros segments.

Example collector:

private DocTermOrds.TermOrdsIterator reuse = null;

public void collect(int doc) throws IOException {
    ...
    reuse = docTermOrds.lookup(doc, reuse);
    ...
}

public void setNextReader(IndexReader.AtomicReaderContext context) throws IOException {
    docTermOrds = FieldCache.DEFAULT.getDocTermOrds(context.reader, field);
    ....
}

If reuse argument is always null exception doesn't occur.

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Migrated from LUCENE-3377 by Martijn van Groningen (@martijnvg), updated Aug 17 2011

[asfimport]

Michael McCandless (@mikemccand) (migrated from JIRA)

I think we should record which IR instance the DTO.TermOrdsIterator was created on, and then don't reuse the passed instance if it came from a different IR?

Actually we should probably just hold onto & compare the IR.getCoreCacheKey().

[asfimport]

Martijn van Groningen (@martijnvg) (migrated from JIRA)

Actually we should probably just hold onto & compare the IR.getCoreCacheKey().

Seems like a good idea to me.