[SOLR-4366] NPE sometimes in SpellCheckComponent when dictionary name not defined

• Type: Bug
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: 4.0
• Component/s: spellchecker
• Assignee: Unassigned
• Reporter: Jack Krupansky
• Created: 26/Jan/13 21:00
• Updated: 26/Jan/13 21:00

Description

SpellCheckComponent sometimes detects and reports dictionary names that are not defined, but not always. I stumbled on two cases where an NPE occurs rather than a 404 status code return.

Repro:

Add this snippet to the Solr 4.0 example solrconfig.xml:

  <requestHandler name="/spellBug" class="solr.SearchHandler" startup="lazy">
    <lst name="defaults">
      <str name="df">name</str>
      <str name="spellcheck">on</str>
      <str name="spellcheck.dictionary">other-name</str>
    </lst>
    <arr name="last-components">
      <str>spellcheckBug</str>
    </arr>
  </requestHandler>

  <searchComponent name="spellcheckBug" class="solr.SpellCheckComponent">
    <lst name="spellchecker">
      <str name="name">some-name</str>
      <str name="classname">solr.FileBasedSpellChecker</str>
      <str name="sourceLocation">SpellDict.txt</str>
      <str name="buildOnCommit">true</str>
    </lst>
  </searchComponent>

Case 1: spellcheck.build=true parameter specified

Execute this request:

curl "http://localhost:8983/solr/spellBug/?q=test&spellcheck.build=true"

Produces this NPE:

SEVERE: null:java.lang.NullPointerException
        at org.apache.solr.handler.component.SpellCheckComponent.prepare(SpellCheckComponent.java:108)
        at org.apache.solr.handler.component.SearchHandler.handleRequestBody(SearchHandler.java:185)

Case 1a: Ditto for spellcheck.reload parameter specified

curl "http://localhost:8983/solr/spellBug/?q=test&spellcheck.reload=true"

Case 2: spellcheck.q parameter specified

Execute this request:

curl "http://localhost:8983/solr/spellBug/?spellcheck.q=test"

Produces this NPE:

SEVERE: null:java.lang.NullPointerException
        at org.apache.solr.handler.component.SpellCheckComponent.process(SpellCheckComponent.java:130)
        at org.apache.solr.handler.component.SearchHandler.handleRequestBody(SearchHandler.java:206)

The first case fails in the "prepare" method of SpellCheckComponent, while the second case fails in the "process" method. Both methods call getSpellChecker, but then proceed to reference the return value without checking if it is null.