Refuse to open folders with insufficient permissions

[probonopd]

Why do most file managers open folders where the user does not have the permissions to do a directory listing? We should not open them, but show an error message instead.

And we should render emblem-nowrite somewhat like this:

And maybe show the folder grayed out, or something like that.

[louies0623]

I wish the lock was in the lower right corner, it looks more comfortable that way.