Re: Emacs routinely gets stuck in single_kboard mode

[Richard Stallman]

    (Incidentally, this calls top-level from a process filter.  Is that
    supported?)

It should be.

It could make sense to offer some way to unlock single-keyboard state
from another keyboard, as long as it is something that people won't be
likely to do without intending this effect.  It can't be mere C-g,
because people are likely to type C-g without realizing the situation
they are in.  Can you think of a good interface?

Perhaps there could be a specific menu bar command that would do this.
People would not be likely to push that by accident, especially if it
leads to a submenu containing the item "Confirm and Proceed" before
you really issue the command.