Different Edismax Behavior with user params vs Solr config params on Solr 8.

[Kerwin <ke...@gmail.com>]

Hi,
I am upgrading from Solr 6.5.1 to solr 8.6.1 and have noticed a change in
the Edismax parser behavior which is affecting our search results. If user
operators are present in the search query, the Solr 6 behavior was to take
mm parameters from the user query string which was 0% by default if not
present. However in Solr 8, it is taking mm parameter specified in the Solr
request handler config which is 100%, see config below.

Hence the user query "samsung OR nokia" works in Solr 6 and is not working
in Solr 8 anymore when documents do not have both strings. This is
affecting our search results. Could you suggest why there is this
difference and how to resolve this?

A simple example config is as follows:

<requestHandler name="/search" class="solr.SearchHandler">
   <lst name="defaults">
     <str name="q">
          {!edismax
          qf=manu
          mm=100% v=$qq}
      </str>
    </lst>
</requestHandler>

    The user query is:
    http://localhost:8983/solr/search?qq=spring OR boot.

    Appreciate any pointers which could resolve this. One solution is to
create two search handlers and check if there are parameters in the user
query before-hand, but I'd prefer this as a last resort.