How to use AndWhere instead of OrWhere when I want to search two parameters?

When I use the search url like "user?search=name:job;guest:0&searchFields=name:like;guest:=",
The RequestCriteria build the query `name like '%job%' OR guest = 0`
But I want it build query like `name like '%job%' And guest = 0`
How can I do that?
I read the source code and I find in `RequestCriteria:: apply`,
on line 54 ,`$modelForceAndWhere = false;` so $modelForceAndWhere is always has
`false` value ,so the query is always in orWhere case
Is this a bug?