correct double return of search when query fail (refs #4303)
add exception in SearchDoc::join() (refs #4299, refs #4300)
also generalize exception to addGeneralFile
correct searchDoc count cache (refs #4305)
Merge pull request #1021 from Eric-Brison/3.2-I4300

Correct some error returns in SearchDoc (closes #4299, closes #4300, closes #4303, closes #4305)