bug#25860: 25.1; Double macro execution

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Eli Zaretskii <eliz@gnu.org> writes:

> I admit that I don't see myself as an expert on all the complexity
> that goes on in keyboard.c and friends.  With this change,
> kmacro-tests.el still passes, but I'm not sure that's good enough
> (e.g., can a macro define another macro when it runs? if so, this
> change will get in the way).

AFAICT, you can't define a macro from a macro:

    DEFUN ("start-kbd-macro", Fstart_kbd_macro, Sstart_kbd_macro, 1, 2, "P",
    ...
    {
      if (!NILP (KVAR (current_kboard, defining_kbd_macro)))
        error ("Already defining kbd macro");

Not sure if there might be some other complications though.