Disable global minor mode by default in hidden buffers

[memeplex]

Many major modes internally use hidden buffers (those starting with a space, as described here). Some modes use these buffers to font lock blocks of code using some major mode (for example, both python.el and org mode do that). When yasnippet is enabled in this kind of buffers bad things might happen while programatically inserting contents. In particular, I've seen the jit font locker complaining about args out of range when yas-mode was enabled. This kind of errors are really difficult to trace and I see no point in enabling snippets in buffers where nobody will type anything, anyway. Could you add something like (lambda () (string-prefix-p " " (buffer-name))) by default to yas-dont-activate-functions in order to play well with major modes?

[npostavs]

With org-mode there might still be some extra complications because there is some non-working code that attempts to transfer the snippet overlays into the temp buffer. So I'm not entirely sure what's going to happen there, but not enabling yas-minor-mode in temp buffers makes sense anyway.

[memeplex]

Thanks, Noam!