So, after struggling with horrible interface choices of Xcode 4, I'm finally on 5.1.1.
The tabs became almost usable. Double clicking can be configured to open a file in a new tab. Good. Double clicking another file opens it in a new tab. Good. Double clicking first file again switches to previously open tab. Good! Double clicking first file while it is open in current tab opens a second tab with that file. Ok, I can live with that, since from there on they just switch from one to another.
So far a surprisingly sane behavior.
Unless you make a single click in the navigation panel by mistake. Single click opens whatever you click in the current tab, all logic and reason be damned.
The question is, how to change single click behavior to "Use separate tab" (or however Xcode refers to that behavior)?
Is there any way to disable single clicks from doing anything at all aside from highlighting the selection?