Window error-handler lossage.

[David L. Andre <DLA at MIT-AI>]

    Date: 14 JAN 1982 2328-PST
    From: rwg@mc
    To:   BUG-LISPM at MIT-AI

    In ETHER 24.5, System 78.40, microcode 841, on Xerox Lisp Machine Two:

    In the window EH, trying to Set Arg an instance var takes CDR of the symbol.

I couldn't duplicate this, but I got some other funny behavior.  What I
did was:
(funcall tv:selected-window ':funcall-inside-yourself #'error "foo")
Then I went into the window error handler.  I "Set Arg"ed #'error to
'error, and "Set Arg"ed the rest arg to ("bar").  I then did a retry,
and got ERROR: foo.  The second arg had been set correctly, but the rest
arg hadn't.

I then attempted to use Set Arg on instance variables.  From that time
on, whenever I used Set Arg, I got the message "That is not an argument
or a local", regardless of what I was pointing at, and even when I
re-entered the window error-handler.

Furthurmore, when I was typing this message (in ZMail), I did c-m-Break,
c-m-W, and got into the cold load stream when the pdl overflowed.
Continuing from that did get me into the window error-handler.