Search for messages where query matches subject *or* body, not *and*

Hi,
I noticed that the search function searches for messages where the query string is contained both in the message's subject and body. This isn't what I'd expect from a simple search feature, it certainly surprised me. Looking at the code led to the assumption that the intent probably is to search for messages where the query string is contained in subject *or* body.

If I'm right about the actual intent of the function, replacing AndTerm by OrTerm would fix it.