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Uwe Schindler edited comment on LUCENE-4546 at 11/7/12 9:25 PM: ---------------------------------------------------------------- Attached the corrected testcase, which passes. -BTW: Your SorterTemplate implementation fails with with mergeSort completely- :-) _(this was incorrect, mergeSort does not use the pivot methods)_ was (Author: thetaphi): Attached the corrected testcase, which passes. BTW: Your SorterTemplate implementation fails with with mergeSort completely :-) > SorterTemplate.quicksort incorrect > ---------------------------------- > > Key: LUCENE-4546 > URL: https://issues.apache.org/jira/browse/LUCENE-4546 > Project: Lucene - Core > Issue Type: Bug > Components: core/other > Affects Versions: 3.6.1, 4.0, 4.1 > Reporter: Stefan Pohl > Assignee: Uwe Schindler > Labels: patch > Fix For: 3.6.1, 4.0, 4.1 > > Attachments: SorterTemplate.java.patch, TestSorterTemplate.java, > TestSorterTemplate.java > > > On trying to use the very useful o.a.l.utils.SorterTemplate, I stumbled upon > inconsistent sorting behaviour, of course, only a randomized test caught > this;) > Because SorterTemplate.quicksort is used in several places in the code > (directly BytesRefList, ArrayUtil, BytesRefHash, CollectionUtil and > transitively index and search), I'm a bit puzzled that this either hasn't > been caught by another higher-level test or that neither my test nor my > understanding of an insufficiency in the code is valid;) > If the former holds and given that the same code is released in 3.6 and 4.0, > this might even be a more critical issue requiring a higher priority than > 'major'. > So, can a second pair of eyes please have a timely look at the attached test > and patch? > Basically the current quicksort implementation seems to assume that luckily > always the median is chosen as pivot element by grabbing the mid element, not > handling the case where the initially chosen pivot ends up not in the middle. > Hope this and the test helps to understand the issue. > Reproducible, currently failing test and a patch attached. -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators For more information on JIRA, see: http://www.atlassian.com/software/jira --------------------------------------------------------------------- To unsubscribe, e-mail: dev-unsubscr...@lucene.apache.org For additional commands, e-mail: dev-h...@lucene.apache.org