I have a solr index where we removed a field from the schema but it still had some documents with that field in it. Queries using the standard response handler had no problem but the &wt=python handler would break on any query (with fl="*" or asking for that field directly) with:
SolrHTTPException: HTTP code=400, reason=undefined_field_oldfield I "fixed" it by putting that field back in the schema. One related weirdness is that fl=oldfield would cause the exception but not fl=othernonschemafield -- that is, it would only break on field names that were not in schema but were in the documents. I know this is undefined behavior territory but it was still weird that the standard response writer does not do this-- if you give a nonexistent field name to fl on wt=standard, either one that is in documents or is not -- it happily performs the query just skipping the ones that are not in the schema.
