bug#15994: 24.3.50; emacs_backtrace.txt

[Drew Adams <drew.adams@oracle.com>]

> I have just installed some code that hopefully will allow us to find
> out where these crashes come from.  This code adds the following 2
> lines at the beginning of emacs_backtrace.txt:
>   Exception 0xc0000005 at this address:
>   1205b6c

Sounds great. Thanks, Eli.

> (The exception code and the address will be different in each case, of
> course.)  We could then use this information to begin unlocking the
> mystery.  I have a guess as to what causes the crashes, but I'd like
> some confirmation before I embark on a wild goose chase.
> 
> I hope that the code really does its job in your crashes -- I could
> only simulate a simple crash to test it, so I cannot be sure.
> 
> Also, could you perhaps post some minimal Lisp that would recreate
> your typical frame configuration starting from "emacs -Q"?

I have a lot in my setup.  I would guess, however, that the problems
we're encountering have mostly to do with the overall frames setup.
That is defined by libraries hexrgb.el (a utility) and oneonone.el
(frames setup).

And I use this:
(defconst special-display-regexps '("[ ]?[*][^*]+[*]"))

In addition to that, I use the settings in setup.el, some of which
might be relevant, but probably not.

All of the code is in the Emacs-Wiki Elisp area:
http://www.emacswiki.org/emacs/elisp-area-compact-no-bootstrap.html?action=elisp-area;context=0

For example, oneonone.el is here:
http://www.emacswiki.org/emacs-en/download/oneonone.el

You can also get oneonone.el and hexrgb.el from MELPA, as packages.

My guess is that hexrgb.el, oneonone.el, plus `special-display-regexps'
will get you close enough to what I use.

> I'm guessing you have a minibuffer-only frame, and pop-up-frames is
> non-nil, but how many frames of what dimensions and relative location
> do you usually have?  Perhaps having that information would provide
> valuable clues.

I have a variable number of frames at any time, of varying sizes.
Typically each shows a single buffer, and most are in Emacs-Lisp mode.
I usually have at least one Dired frame.

At any time, most of the frames have been "thumbified", which means that
they have been shrunk so they are like icons on the desktop (maybe 1.5
inches by 2 inches - but again, of variable size).  I also frequently
shrink or enlarge the font (and thus also frame) size of individual
buffers slightly (i.e., not as tiny as thumbnails), depending on what
I'm doing.

You probably do not need to care about any of that (e.g. thumbnail
frames).

Also, FYI, I cannot use the latest Emacs binary I downloaded (built
2013-12-02), because it completely breaks thumbifying, and more
generally, resizing frames by shrinking their fonts (bug #16028).
I've reverted to a build from 2013-11-11.

The build from 11-11 gives me the crash, but how will I get your new
backtrace without picking up a newer binary?  I'll gladly do that once
the frame-sizing regression is fixed.  But I don't want to use Emacs in
that broken state, I'm afraid.  Hopefully that fix will come soon, so
I can give you some more meaningful backtrace files.

[FYI - I will not be able to use Emacs 24.4 and later, if bug #16028 is
not fixed.  I would not use Emacs without being able to shrink/enlarge
frame & font together.  I used to long ago, of course, but I would
prefer to continue with Emacs 24.3 rather than go back to not being
able to quickly resize everything in a frame.]
 
> I'm only interested in frame configuration at this point, not in any
> other customizations.

Understood.

Thanks for working on this.