Re: usr1-signal, usr2-signal, etc.

[Richard Stallman]

    I'm concerned about the case that kbd_buffer_store_event_hold is
    called from the signal-handler context while it is also executed in
    the normal context.  This has already existed for SIGUSR1 and SIGUSR2
    before your change, though.

Since people hardly ever use SIGUSR1 and SIGUSR2,
a bug that happens only a small fraction of the time when they
are called might never have happened.  But if it happens for
signals that are more common, it will start to occur.
So it is good that you noticed this.

We should fix it now.