RE: debugger with pop-up-frames non-nil: keeps creating new frames

[Drew Adams]

        The patch was against the Emacs-CVS code.  After patching the
        file, you have
        to byte-compile it and you have to redump Emacs because
        it's a preloaded file, IIRC.

    I can download the CVS
    file, patch it, byte-compile it, and load the byte-compiled
    file (using load-file). Wouldn't that be sufficient?

I did that, and I don't see the bug using only my steps 1-6 from before.

However:

If I do (setq special-display-regexps '("[ ]?[*][^*]+[*]")), then when I hit
`d' in the debugger, the debugger frame iconifies. That is, I use the same
steps 1-6 as before, except this time *Backtrace* is considered a
special-display buffer: emacs -q, load the patched cvs debug.elc, set
variables pop-up-frames and display-buffer-reuse-frames to `t'.

I also tried substituting `quit-window' for `bury-buffer' in the code. That
solves the iconification problem, but the frame is effectively erased and
redrawn at each debugger `d', producing a flashing effect.

I don't understand:

 - Why bury-buffer iconifies.
 - Why we would want to use bury-buffer here at all? Why not leave it, since
we are still in the debugger? What was wrong with the way it worked before
(say, in Emacs 20)?

The various versions I've tried so far do these things:

   . flash the frame/buffer at each debugger step
   . iconify the frame at each debugger step
   . create a new frame at each debugger step

So far, I don't like what I see.