defaultSearchField and param df are messed up in 3.6.x

[Bernd Fehling]

Unfortunately I must see that defaultSearchField and param df are
pretty much messed up in solr 3.6.x
Yes, I have seen issue SOLR-2724 and SOLR-3292.

So if defaultSearchField has been removed (deprecated) from schema.xml then why
are the still calls to 
"org.apache.solr.schema.IndexSchema.getDefaultSearchFieldName()"?

All these calls get no result, because there is no defaultSearchField.
This also breaks edismax (ExtendedDismaxQParserPlugin) and several other.
As example in method parse() it tries
...
    queryFields = U.parseFieldBoosts(solrParams.getParams(DMP.QF));
    if (0 == queryFields.size()) {
      queryFields.put(req.getSchema().getDefaultSearchFieldName(), 1.0f);
    }
...

Guess what, yes no result and an empty search :-(
A grep for "getDefaultSearchFieldName" pointed out that there are several
places where this method is still in use for sorl 3.6.x.

A workaround is to enable defaultSearchField in schema.xml again.

Or to fix all places in the code, e.g. for ExtendedDismaxQParserPlugin method 
parse()
must then read
...
    queryFields = U.parseFieldBoosts(solrParams.getParams(DMP.QF));
    if (0 == queryFields.size()) {
      queryFields.put(solrParams.getParams("df"));
    }
...

or something similar.

I would also recommend to enable defaultOperator in schema.xml again. Just in 
case
they forgot to fix places where they try to access defaultOperator.


Regards
Bernd