[SOLR-13202] Three NullPointerExceptions in org.apache.solr.search.JoinQuery.hashCode()

• Type: Bug
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: 9.0
• Labels: diffblue newdev

Environment

Steps to reproduce

• Use a Linux machine.
• Build commit ea2c8ba of Solr as described in the section below.
• Build the films collection as described below.
• Start the server using the command ./bin/solr start -f -p 8983 -s /tmp/home
• Request the URL given in the bug description.

Compiling the server

git clone https://github.com/apache/lucene-solr
cd lucene-solr
git checkout ea2c8ba
ant compile
cd solr
ant server

Building the collection

We followed Exercise 2 from the Solr Tutorial. The attached file (home.zip) gives the contents of folder /tmp/home that you will obtain by following the steps below:

mkdir -p /tmp/home
echo '<?xml version="1.0" encoding="UTF-8" ?><solr></solr>' > /tmp/home/solr.xml

In one terminal start a Solr instance in foreground:

./bin/solr start -f -p 8983 -s /tmp/home

In another terminal, create a collection of movies, with no shards and no replication, and initialize it:

bin/solr create -c films
curl -X POST -H 'Content-type:application/json' --data-binary '{"add-field": {"name":"name", "type":"text_general", "multiValued":false, "stored":true}}' http://localhost:8983/solr/films/schema
curl -X POST -H 'Content-type:application/json' --data-binary '{"add-copy-field" : {"source":"*","dest":"_text_"}}' http://localhost:8983/solr/films/schema
./bin/post -c films example/films/films.json

• Assignee: Unassigned
• Reporter: Cesar Rodriguez
• Created: 31/Jan/19 12:25
• Updated: 22/Oct/19 11:24

Description

Requesting any of the following URLs causes Solr to return an HTTP 500 error response:

http://localhost:8983/solr/films/select?fq={!join%20from=b%20to=a}
http://localhost:8983/solr/films/select?fq={!join%20to=a}
http://localhost:8983/solr/films/select?fq={!join}

The error response seems to be caused by the following uncaught exception:
 

java.lang.NullPointerException
 at org.apache.solr.search.JoinQuery.hashCode(JoinQParserPlugin.java:578)
 at org.apache.solr.search.QueryResultKey.<init>(QueryResultKey.java:52)
 at org.apache.solr.search.SolrIndexSearcher.getDocListC(SolrIndexSearcher.java:1328)
 at org.apache.solr.search.SolrIndexSearcher.search(SolrIndexSearcher.java:567)
 at org.apache.solr.handler.component.QueryComponent.doProcessUngroupedSearch(QueryComponent.java:1434)
 at org.apache.solr.handler.component.QueryComponent.process(QueryComponent.java:373)
 at org.apache.solr.handler.component.SearchHandler.handleRequestBody(SearchHandler.java:298)
 at org.apache.solr.handler.RequestHandlerBase.handleRequest(RequestHandlerBase.java:199)
 at org.apache.solr.core.SolrCore.execute(SolrCore.java:2559)
[...]

The problem seems to be related with method hasCode in the class org.apache.solr.search.JoinQuery:

  @Override
  public int hashCode() {
    int h = classHash();
    h = h * 31 + fromField.hashCode();
    h = h * 31 + toField.hashCode();
    h = h * 31 + q.hashCode();
    h = h * 31 + Objects.hashCode(fromIndex);
    h = h * 31 + (int) fromCoreOpenTime;
    return h;
  }

The URLs provided above selectively leave uninitialized the fields fromField, fromIndex, q, and toField, but all of these fields are accessed by this method.
 
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