[LUCENE-3600] BlockJoinQuery advance fails on an assert in case of a single parent with child segment

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 3.5, 4.0-ALPHA
• Fix Version/s: 3.6, 4.0-ALPHA
• Component/s: modules/join
• Lucene Fields: New
• Assignee: Michael McCandless
• Reporter: Shay Banon
• Created: 27/Nov/11 10:55
• Updated: 28/Aug/22 13:02
• Resolved: 27/Nov/11 19:52

Description

The BlockJoinQuery will fail on an assert when advance in called on a segment with a single parent with a child. The call to parentBits.prevSetBit(parentTarget - 1) will cause -1 to be returned, and the assert will fail, though its valid. Just removing the assert fixes the problem, since nextDoc will handle it properly.

Also, I don't understand the "assert parentTarget != 0;", with a comment of each parent must have one child. There isn't really a reason to add this constraint, as far as I can tell..., just call nextDoc in this case, no?