A pretty crazy bug report was filed with Apple on Thursday afternoon. According to a copy of the bug on Open Radar, all you have to do is type the text File:/// into almost any window in any app on OS X to immediately crash the app. We’ve managed to crash Google Chrome, Safari, TextEdit and more with this bug, although a few rare apps seem to be immune.
In order to make this happen, you’ll need to type File:/// into just about any OS X app, including all three slashes and the capital F. The bug report filed with Apple speculates that this is caused by the spellchecker built into OS X, but since it appears to affect text boxes such as the Safari location bar that don’t include spellcheck, we find this theory unlikely. The bug affects all Macs running Mountain Lion, but does not have any effect on Lion or Snow Leopard.
Since the bug has been reported to Apple, it will likely be patched at some point. It’s not exactly a critical one though, so it may take a while. In the meantime, if you tested this out and your app is automatically crashing itself all the time, go to System Preferences, go to Language & Text, then Text, and uncheck “Correct spelling automatically” as well as “Use symbol and text substitution.”