bug#7932: 23.1; overprinting / cursor misalignment after certain characters

[David McArthur <david@davidmcarthur.com>]

On 01/29/2011 05:10 AM, Jan Djärv wrote:
 > Does the situation fix itself if you do C-l or iconify and restore
 > the Emacs frame?

Yes.  The problem then re-surfaces if I run the cursor back over those 
characters.

 > Can you put the cursor on one of the characters and do C-c
 > C-x C-= and mail the results?

	C-c C-x C-= is undefined

Am I trying to do xscheme-send-control-x-interrupt?  C-h a xscheme gives me

	No apropos matches for `xscheme'


On 01/29/2011 10:33 AM, Jan Djärv wrote:
 > Another thing to check, can you do:
 >
 > % xrdb -query|grep Xft
 >
 > before and after you connect the external monitor?

The result is identical before and after:

Xft.antialias:	1
Xft.dpi:	96
Xft.hinting:	1
Xft.hintstyle:	hintslight
Xft.lcdfilter:	lcddefault
Xft.rgba:	rgb


On 01/29/2011 05:10 AM, Jan Djärv wrote:
> Can you try a newer Emacs version? 23.2 has been out a while.
> If you can try trunk also that would be great (see
> http://savannah.gnu.org/projects/emacs/).

Okay, I'll try this next.


On 01/28/2011 01:52 PM, Stefan Monnier wrote:
 > While this may very well be an Emacs bug, I think there's a chance
 > this is a bug in your X server (at least, I've seen somewhat similar
 > problems in the past with a bug in some of the acceleration code in
 > the `nv' driver).
 >
 > Can you maybe try to fiddle with your X11 driver, like turning off
 > the acceleration, and/or switching between EXA, UXA, XAA, and/or
 > whichever other acceleration framework they came up with?

I don't know anything about X11 drivers, so this may take me a little 
while to figure out how to do.  I'll try it second.


Thanks,

-- 
David McArthur
david@davidmcarthur.com


 > David McArthur skrev 2011-01-28 16.41:
 >> Upon typing certain characters in any buffer (including the
 >> minibuffer) the
 >> cursor becomes misaligned and text is overprinted. These characters are:
 >> AKkRrTVWwXxYyZ. This problem only occurs when I have my second monitor
 >> enabled.
 >>
 >> The cursor is a blinking black box such that when the cursor is on 
top of
 >> text, the text is printed in inverse (off-white). What happens after
 >> typing
 >> one of AKkRrTVWwXxYyZ is that the black box is moved to the next
 >> position, but
 >> the character I just typed blinks as though the cursor were still on
 >> top of
 >> it. The next letter I type then appears twice: both in the correct
 >> position,
 >> and also overprinted on top of the problem character to the left.
 >> Also, the
 >> problem character is then re-printed one position to the left of where
 >> I typed
 >> it, overprinting on the character before it. Further typing appears
 >> normally,
 >> as long as the characters are not any of AKkRrTVWwXxYyZ.
 >>
 >> For example, if I type "text" weird behavior starts after I type the
 >> lowercase
 >> "x". What I see before I type the second "t" is "tex" with the
 >> blinking black
 >> box to the right of x, but x is also blinking (alternating black and
 >> off-white). After typing the second "t", what I see is "t#*t" where #
 >> is "x"
 >> printed on top of "e" and * is "t" printed on top of "x". If I move
 >> the cursor
 >> away and type C-l the text is redrawn correctly, but if I move the
 >> cursor back
 >> over the problematic characters, the overprinting reoccurs.
 >>
 >> This is on my laptop running Ubuntu Maverick. The problem occurs when
 >> I have
 >> my external monitor enabled (regardless of which monitor the emacs
 >> window is
 >> on). When the external monitor is disabled, the problem does not occur.
 >>
 >> Here is a snippet from lspci -v
 >>
 >> 00:02.0 VGA compatible controller: Intel Corporation Mobile 945GM/GMS,
 >> 943/940GML Express Integrated Graphics Controller (rev 03) (prog-if 00
 >> [VGA
 >> controller])
 >> Subsystem: Sony Corporation Device 81e6
 >> Flags: bus master, fast devsel, latency 0, IRQ 16
 >> Memory at dc200000 (32-bit, non-prefetchable) [size=512K]
 >> I/O ports at 1800 [size=8]
 >> Memory at c0000000 (32-bit, prefetchable) [size=256M]
 >> Memory at dc300000 (32-bit, non-prefetchable) [size=256K]
 >> Expansion ROM at <unassigned> [disabled]
 >> Capabilities: [90] MSI: Enable- Count=1/1 Maskable- 64bit-
 >> Capabilities: [d0] Power Management version 2
 >> Kernel driver in use: i915
 >> Kernel modules: i915
 >>
 >>
 >> Here is the info from M-x report-emacs-bug
 >>
 >> In GNU Emacs 23.1.1 (i686-pc-linux-gnu, GTK+ Version 2.22.0)
 >> of 2010-11-26 on vernadsky, modified by Debian
 >> Windowing system distributor `The X.Org Foundation', version
 >> 11.0.10900000
 >> configured using `configure '--build=i686-linux-gnu'
 >> '--host=i686-linux-gnu'
 >> '--prefix=/usr' '--sharedstatedir=/var/lib' '--libexecdir=/usr/lib'
 >> '--localstatedir=/var/lib' '--infodir=/usr/share/info'
 >> '--mandir=/usr/share/man' '--with-pop=yes'
 >> 
'--enable-locallisppath=/etc/emacs23:/etc/emacs:/usr/local/share/emacs/23.1/site-lisp:/usr/local/share/emacs/site-lisp:/usr/share/emacs/23.1/site-lisp:/usr/share/emacs/site-lisp:/usr/share/emacs/23.1/leim' 

 >>
 >> '--with-x=yes' '--with-x-toolkit=gtk' '--with-toolkit-scroll-bars'
 >> 'build_alias=i686-linux-gnu' 'host_alias=i686-linux-gnu'
 >> 'CFLAGS=-DDEBIAN -g
 >> -O2' 'LDFLAGS=-g' 'CPPFLAGS=''
 >>
 >> Important settings:
 >> value of $LC_ALL: nil
 >> value of $LC_COLLATE: nil
 >> value of $LC_CTYPE: nil
 >> value of $LC_MESSAGES: nil
 >> value of $LC_MONETARY: nil
 >> value of $LC_NUMERIC: nil
 >> value of $LC_TIME: nil
 >> value of $LANG: en_US.utf8
 >> value of $XMODIFIERS: nil
 >> locale-coding-system: utf-8-unix
 >> default-enable-multibyte-characters: t
 >>
 >> Major mode: Outline
 >>
 >> Minor modes in effect:
 >> goto-address-mode: t
 >> tooltip-mode: t
 >> tool-bar-mode: t
 >> mouse-wheel-mode: t
 >> menu-bar-mode: t
 >> file-name-shadow-mode: t
 >> global-font-lock-mode: t
 >> font-lock-mode: t
 >> blink-cursor-mode: t
 >> global-auto-composition-mode: t
 >> auto-composition-mode: t
 >> auto-encryption-mode: t
 >> auto-compression-mode: t
 >> line-number-mode: t
 >> transient-mark-mode: t
 >> view-mode: t
 >>
 >> Recent input:
 >> r <return> s t u v w <return> x <return> y <return>
 >> z <up> <down> <down> <return> <return> A K R T V W
 >> X Y Z k r w x y <up> <right> C-l C-k C-/ <down> <left>
 >> <left> <left> <left> <left> <left> <left> <left> <left>
 >> <left> <left> <left> <left> <left> <left> <left> <left>
 >> <left> <down> <down> <right> <right> <right> k <right>
 >> r <right> <right> <right> w <right> x <right> y <right>
 >> C-k C-l <up> C-l <down> <down> <down> <return> <return>
 >> C-h C-p C-s c u r s o <right> <left> <left> <left>
 >> <left> <left> <left> <left> <left> <down> <right> <right>
 >> <down> <up> <left> <left> <left> <left> <right> <right>
 >> <right> <right> <right> <left> <left> <left> <right>
 >> <right> <right> <right> <right> <right> <right> <right>
 >> <right> <right> <right> <right> <right> <right> <right>
 >> <help-echo> <help-echo> <help-echo> <help-echo> <help-echo>
 >> <help-echo> <help-echo> <help-echo> <help-echo> <help-echo>
 >> <help-echo> <help-echo> <help-echo> <help-echo> <help-echo>
 >> <help-echo> <help-echo> <help-echo> <help-echo> <help-echo>
 >> <help-echo> <help-echo> <help-echo> <help-echo> <help-echo>
 >> <help-echo> C-s C-s C-s <down> <down> <down> <down>
 >> <up> <up> C-x b <return> <up> <up> <right> <right>
 >> <right> <right> <right> <right> <down> C-x b <return>
 >> C-l <up> <up> <up> <up> <up> <up> <up> <up> <up> <up>
 >> <up> <up> <up> <up> <up> <up> <up> <up> <up> <up> <up>
 >> <up> <up> <up> <next> <prior> C-s C-s <down> <up> <up>
 >> <up> <up> <up> <up> C-s C-s <up> <up> <up> <up> <up>
 >> <up> <up> <up> <up> <up> <up> <up> <up> <up> <up> <up>
 >> <up> <up> <up> <up> <up> <up> <up> <up> <up> <up> <up>
 >> <up> <up> <up> C-s C-s C-s C-s C-s C-s <down> <down>
 >> <down> <down> <up> <up> <up> <up> <up> <up> C-s C-s
 >> C-s C-s C-s C-s C-s C-s C-s C-s M-x r e p o r t e m
 >> a c s <backspace> <backspace> <backspace> <backspace>
 >> <backspace> SPC e m a c s <tab> <return>
 >>
 >> Recent messages:
 >> Loading /var/cache/dictionaries-common/emacsen-ispell-default.el
 >> (source)...done
 >> Loading debian-ispell...done
 >> Loading /var/cache/dictionaries-common/emacsen-ispell-dicts.el
 >> (source)...done
 >> Loading /etc/emacs/site-start.d/50dictionaries-common.el (source)...done
 >> For information about GNU Emacs and the GNU system, type C-h C-a.
 >> Undo!
 >> Note: file is write protected
 >> View mode: type C-h for help, h for commands, q to quit.
 >> Mark saved where search started [6 times]
 >> /usr/bin/mail is not an executable. Setting mail-interactive to t.