Synonym Expansion in Spellchecking Field Solr 4.3.1

[Brendan Grainger]

Hi All,

I've been debugging an issue where the query 'tpms' would make the
spellchecker throw the following exception:

21021 [qtp91486057-17] ERROR org.apache.solr.servlet.SolrDispatchFilter  –
null:java.lang.StringIndexOutOfBoundsException: String index out of range:
-1
at java.lang.AbstractStringBuilder.replace(AbstractStringBuilder.java:789)
at java.lang.StringBuilder.replace(StringBuilder.java:266)
at
org.apache.solr.spelling.SpellCheckCollator.getCollation(SpellCheckCollator.java:190)
at
org.apache.solr.spelling.SpellCheckCollator.collate(SpellCheckCollator.java:75)


I have the following synonyms defined for tpms:

tpms,service tire monitor,tire monitor,tire pressure monitor,tire pressure
monitoring system,tpm,low tire warning,tire pressure monitor system

Note that if you query any of the other synonyms there is no issue, only
tpms.

Looking at my field definition for my spellchecker I realized I am doing
query time synonym expansion:

    <fieldType name="text_spell" class="solr.TextField"
positionIncrementGap="100" omitNorms="true">
      <analyzer type="index">
        <tokenizer class="solr.StandardTokenizerFactory"/>
        <filter class="solr.StopFilterFactory"
                ignoreCase="true"
                words="lang/stopwords_en.txt"
                enablePositionIncrements="true"
                />
        <filter class="solr.LowerCaseFilterFactory"/>
        <filter class="solr.StandardFilterFactory"/>
      </analyzer>
      <analyzer type="query">
        <tokenizer class="solr.StandardTokenizerFactory"/>
        <filter class="solr.SynonymFilterFactory" synonyms="synonyms.txt"
ignoreCase="true" expand="true"/>
        <filter class="solr.StopFilterFactory"
                ignoreCase="true"
                words="lang/stopwords_en.txt"
                enablePositionIncrements="true"
                />
        <filter class="solr.LowerCaseFilterFactory"/>
        <filter class="solr.StandardFilterFactory"/>
      </analyzer>
    </fieldType>

I copied this field definition from:
http://wiki.apache.org/solr/SpellCheckingAnalysis. As the issue seemed
related to synonyms I removed the SynonymFilterFactory and everything
works.

I'm going to try to create a reproducible test case for the crash, but
right now I'm wondering what I lose by not having synonym expansion when
spell checking?

Thanks
Brendan