Re: Frame resizing causes a crash

[Riku Saikkonen]

Hi,

I reported the following bug here about a week ago, but haven't heard
anything on it since. Could someone try to reproduce the bug, so that
I know that it's not only my Emacsen that are at fault? In particular,
it would be nice to know if the current CVS version has this bug...

rjs@cs.hut.fi (Riku Saikkonen) writes:
>I found an odd bug related to resizing an Emacs frame when there are
>several windows inside it. Resizing a particular window configuration
>to a smaller height causes a crash in text mode, and strange behaviour
>in an X window.
>
>I use GNU Emacs 21, and this seems to happen both in GNU/Linux and in
>Solaris. I tried these three Emacsen, and they all have the bug:
> - GNU Emacs 21.1.1 (sparc-sun-solaris2.8, X toolkit) of 2002-01-31 on vernal
> - GNU Emacs 21.2.1 (i386-redhat-linux-gnu, X toolkit, Xaw3d scroll bars)
>   of 2002-04-09 on porky.devel.redhat.com
> - GNU Emacs 21.2.1 (i386-debian-linux-gnu, X toolkit, Xaw3d scroll bars)
>   of 2002-03-22 on raven, modified by Debian
>
>To reproduce the bug:
>
>1. Start a copy of Emacs, and resize it to 80x58 characters.
>
>2. Execute the following Lisp code, and use M-x my-set-windows. (This
>   produces three windows, one of which is only 4 lines high.)
>
>   (defun my-set-windows ()
>     (interactive)
>     (delete-other-windows)
>     (split-window-vertically)
>     (set-window-text-height nil 4)
>     (other-window 1)
>     (split-window-vertically))
>
>3. Resize the Emacs frame to 80x24 characters.
>
>When I do this in a text-mode Emacs (inside an xterm), it immediately
>crashes with the message:
>Fatal error (6).Aborted
>
>When running Emacs in an X window, the bug doesn't crash Emacs, but
>causes some very strange behaviour on the display: Emacs shows the
>text as if there were several windows, but there is only one mode
>line. Moving around and using C-l reveals that there are several
>windows, but they seem to overrlap. C-x o jumps between two windows,
>and from moving around in them, it appears that the upper one occupies
>lines 1-12 in the 24-line display and the lower one uses lines 8-19
>(so both are 12 lines high - the text area is 19 lines long in a
>window with geometry 80x24 using the default menu and tool bars).
>Thus, the mode line of the upper window is displayed on the 13th line,
>but often gets overwritten by redrawing of the lower window.
>
>The same kind of bug appears to happen on other window sizes, and also
>if I resize the windows manually (using C-x ^ or the mouse on the mode
>lines) to a similar configuration. But not all configurations of three
>windows produce the bug; it appears that the problem is related to
>sizing a very small window to an even smaller size when the frame is
>made much smaller.
>
>A backtrace from a core dump generated by the Emacs 21.2.1 on the
>Debian GNU/Linux system does not appear helpful:
>
>(gdb) bt
>#0  0x40305781 in kill () from /lib/libc.so.6
>#1  0x080ce1db in XMapRaised ()
>#2  0x403056b8 in sigaction () from /lib/libc.so.6
>#3  0x080926d3 in XMapRaised ()
>#4  0x080942e1 in XMapRaised ()
>#5  0x08055620 in XMapRaised ()
>#6  0x08054ebb in XMapRaised ()
>#7  0x08052c80 in XMapRaised ()
>#8  0x0806670c in XMapRaised ()
>#9  0x08066b0a in XMapRaised ()
>#10 0x0814dc97 in error ()
>#11 0x08056b43 in XMapRaised ()
>#12 0x080d2523 in abort ()
>#13 0x080d8a33 in abort ()
>#14 0x080d0bf4 in abort ()
>#15 0x08121dc9 in re_compile_pattern ()
>#16 0x080d07d8 in abort ()
>#17 0x0812195d in re_compile_pattern ()
>#18 0x080d0787 in abort ()
>#19 0x080d0301 in abort ()
>#20 0x080d0430 in abort ()
>#21 0x080cf39f in abort ()
>#22 0x402f514f in __libc_start_main () from /lib/libc.so.6
>(gdb) q

-- 
-=- Rjs -=- rjs@cs.hut.fi, Riku.Saikkonen@hut.fi
"Or there maybe 'tis cloudless night / and swaying beeches bear
the Elven-stars as jewels white / amid their branching hair."
    -- J.R.R. Tolkien