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

[Stefan Monnier <monnier@iro.umontreal.ca>]

> 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.

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?


        Stefan