Well, now I'm totally confused. I tried the app this morning and got the same results. Then I added your little code snippet to the library, ran all the tests (which succeeded), updated the app and ran it. I would have sworn it stayed in the true loop forever, but now I'm not so sure. I closed the app out of xcode, then reopened it and tried the app. It ran fine! This was with your code snippet. Then I decided to simply to go back to my original code and try it. Again, I checked all the tests, and each time I set the appropriate breakpoints to make sure the expected code was being run. Lo and behold I can't get the app to fail now. Just. tried it agaiin and it worked fine. The only difference now to the oriiginal problem is some commented out code. (your snippet).
If I had to guess now, I'd say this is an xcode problem, but I have no way to reproduce or test it. Any thoughts on where to go from here?
Rick