In emacs, if I have two frames open and the mouse is positioned over the other frame (i.e. not over the active one), pressing the
Alt key produces a
While this event does nothing in itself, it disrupts things like
yank-pop, which no longer works if it is bound to
M-y as usual (because instead of the command sequence
yank-pop, we now have
yank-pop, which gives an error "user-error: Previous command was not a yank").
I don't know enough about X-Windows to know if this is emacs' fault or x-windows fault. But it's very annoying. What can I do about this?
[Tried on Emacs versions 24.5, 25.1, and the 26.0 and Ubuntu 16.10.
I initially posted this on the emacs stack exchange but received no responses except a suggestion to post it here.]