Please describe the problem:
I have some people with nicks like "xx" in my roster. If type xx in the search field of the "New Message" dialog and the results are not unique, than no one of results is selected. If you then press enter, you don't write to nick xx, you write to the JID "xx", which is of course malformed. So your message goes to nowhere. 

Steps to reproduce:
1. have a contac with nick "oo" and another with foobar in your roster
2. Open "New message" dialog
3. Search for "oo"
4. Press return

Actual results:
A chat with the not subscribed contact "oo" (this is the complete JID, not the nick) is opened.

Expected results:
If there is a contac with the exact nick like the query (in this example "oo") open a chat to this one. 

Does this happen every time?
yes

Other information:
I am not sure if it's possible to chat with people with just a string as JID without "@" and hostname. I guess not. So don't open chat's with not allowd JIDs, like "nsifgng", "hans" or "oo". 

With three letter nicks I don't have the problem, but if there is no result for the query, it will open a chat to the invalid JID.