[SOLR-13944] CollapsingQParserPlugin throws NPE instead of bad request

• Type: Bug
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 7.3.1
• Fix Version/s: 8.6
• Assignee: Munendra S N
• Reporter: Stefan
• Created: 19/Nov/19 06:47
• Updated: 15/Jul/20 15:10
• Resolved: 18/Mar/20 05:49

Description

 I noticed the following NPE:

java.lang.NullPointerException at org.apache.solr.search.CollapsingQParserPlugin$OrdFieldValueCollector.finish(CollapsingQParserPlugin.java:1021) at org.apache.solr.search.CollapsingQParserPlugin$OrdFieldValueCollector.finish(CollapsingQParserPlugin.java:1081) at org.apache.solr.search.SolrIndexSearcher.buildAndRunCollectorChain(SolrIndexSearcher.java:230) at org.apache.solr.search.SolrIndexSearcher.getDocListNC(SolrIndexSearcher.java:1602) at org.apache.solr.search.SolrIndexSearcher.getDocListC(SolrIndexSearcher.java:1419) at org.apache.solr.search.SolrIndexSearcher.search(SolrIndexSearcher.java:584)

If I am correct, the problem was already addressed in SOLR-8807. The fix does was not working in this case though, because of a syntax error in the query (I used the local parameter syntax twice instead of combining it). The relevant part of the query is:

&fq={!tag=collapser}{!collapse field=productId sort='merchantOrder asc, price asc, id asc'}

After discussing that on the mailing list, I was asked to open a ticket, because this situation should result in a bad request instead of a NullpointerException (see https://mail-archives.apache.org/mod_mbox/lucene-solr-user/201911.mbox/%3CCAMJgJxTuSb%3D8szO8bvHiAafJOs08O_NMB4pcaHOXME4Jj-GO2A%40mail.gmail.com%3E)