If you open the URL in a debug build of TOT and click the Crash button you get
ASSERTION FAILED: Uncaught exception - *** -[NSCFDictionary setObject:forKey:]: attempt to insert nil value
This is coming from createNSDictionary (FrameMac.mm) when the second String in a pair, which is the form field's value, is a NULL string. Before r17378 it was converted to an empty NSString, but now it's converted to nil, which cannot be inserted into the NSDictionary.
Occurs when submitting Bugzilla comments (see Bug 10933 Comment #8).
Fixed in r17408. (I didn't know about this bug report when I fixed it.)
We need a layout test for this.
Created attachment 11275 [details]
Committed revision 17419.
Comment on attachment 11275 [details]