romseygeek opened a new pull request #1618: URL: https://github.com/apache/lucene-solr/pull/1618
Given the input text 'A B A C', an ordered interval 'A B C' will currently return an incorrect internal [2, 3] in addition to the correct [0, 3] interval. This is due to a bug in the ORDERED algorithm, where we assume that after the first interval is returned, the sub-intervals are always in-order. This assumption only holds during minimization, as minimizing an interval may move the earlier terms beyond the trailing terms. For example, after the initial [0, 3] interval is found above, the algorithm will attempt to minimize it by advancing A to [2,2]. Because this is still before C at [3,3], but after B at [1,1], we then try advancing B, leaving it at [Inf,Inf]. Minimization has failed, so we return out original interval of [0,3]. However, when we come to retrieve the next interval, our subintervals look like this: A[2,2], B[Inf,Inf], C[3,3] - the assumption that they are in order is broken. The algorithm sees that A is before B, assumes that therefore all subsequent subintervals are in order, and returns the new interval. This commit fixes things by changing the assumption of ordering to only hold during minimization. When first finding a candidate interval, the algorithm now checks that all sub-intervals appear in order. ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: us...@infra.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: issues-unsubscr...@lucene.apache.org For additional commands, e-mail: issues-h...@lucene.apache.org
