Possible bug with AnalyzingInfixLookupFactory, FileDictionaryFactory and Context Filtering

[Joaquim de Souza]

Hi all,

I asked a question on StackOverflow
<https://stackoverflow.com/questions/66423970/solr-suggester-context-filter-incorrectly-applied-to-filedictionaryfactory>about
a problem I was having with the suggester module, but since then I have
looked into the source code of Solr, and I thinkit is a bug.

Essentially, context filtering is being applied to a suggester that is
backed by a FileDictionaryFactory. According to the docs, this should not
happen, and context filters should be ignored.

This is my config:

<searchComponent name="suggest" class="solr.SuggestComponent">
  <lst name="suggester">
    <str name="name">location</str>
    <str name="lookupImpl">AnalyzingInfixLookupFactory</str>
    <str name="dictionaryImpl">FileDictionaryFactory</str>
    <str name="sourceLocation">tdwg.txt</str>
    <str name="suggestAnalyzerFieldType">text_general</str>
    <str name="highlight">false</str>
  </lst>

  <lst name="suggester">
    <str name="name">common-name</str>
    <str name="lookupImpl">AnalyzingInfixLookupFactory</str>
    <str name="dictionaryImpl">DocumentDictionaryFactory</str>
    <str name="field">region.vernacular_names_t</str>
    <str name="indexPath">common_name_suggest</str>
    <str name="contextField">searchable.context_ss</str>
    <str name="suggestAnalyzerFieldType">text_general</str>
    <str name="highlight">false</str>
  </lst>
</searchComponent>

I have tested this on the latest version of Solr (8.8.1).

The relevant bit of source code is here
<https://github.com/apache/lucene-solr/blob/master/solr/core/src/java/org/apache/solr/spelling/suggest/SolrSuggester.java#L251>.
I would expect suggestions to be null, as the combination of
AnalyzingInfixLookupFactory and FileDictionaryFactor doesn't support
context filtering.

Is there anything I can do to fix this problem?

Thanks,
Joaquim