Tracking Down Snow Leopard’s Apple Events Bug

Matt Neuburg on a devilish Apple events bug in Snow Leopard:

The bug sounds minor, but it is really very important because Apple events are crucial to so much of what goes on under the hood in Mac OS X, and in any case it has caused everyone’s scripts to break (whether written in AppleScript, rb-appscript, or anything else that sends Apple events). The underlying Apple event manager assigns a new return ID to every Apple event, and so sooner or later some Apple event is going to hit the magic FFFF value, and whatever sent that Apple event is going to error out, apparently randomly. You may even have seen such random errors on your machine without knowing it.

★ Wednesday, 14 October 2009