[LUCENE-2190] CustomScoreQuery (function query) is broken (due to per-segment searching)

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 3.1
• Fix Version/s: 2.9.2, 3.0.1, 4.0-ALPHA
• Component/s: core/search
• Lucene Fields: New, Patch Available
• Assignee: Uwe Schindler
• Reporter: Michael McCandless
• Created: 04/Jan/10 11:52
• Updated: 28/Aug/22 12:18
• Resolved: 21/Feb/10 19:12

Description

Spinoff from here:

http://lucene.markmail.org/message/psw2m3adzibaixbq

With the cutover to per-segment searching, CustomScoreQuery is not really usable anymore, because the per-doc custom scoring method (customScore) receives a per-segment docID, yet there is no way to figure out which segment you are currently searching.

I think to fix this we must also notify the subclass whenever a new segment is switched to. I think if we copy Collector.setNextReader, that would be sufficient. It would by default do nothing in CustomScoreQuery, but a subclass could override.