Weird redisplay bug

[Juanma Barranquero]

This redisplay bug is nothing to worry much about, because it only
happens in unusual circunstances. Still, it's quite weird.

Create an empty buffer, and then evaluate the following code:

(progn
  (setq buffer-display-table (or buffer-display-table (make-display-table)))
  (erase-buffer)
  (insert (propertize "text\ntext\r\ntext\n" 'face '(:foreground "yellow")))
  (aset buffer-display-table 13 [0])
  (redisplay t))

The line containing the character set to "\0" in the display table is
wrong. See the attached picture.

Notes:
- The foreground color is irrelevant.
- The fact that there's a non-default foreground color is relevant;
instead of '(:foreground "yellow") you can use a font-lock face, for
example.
- That the character being displayed as "\0" is ^M is not relevant;
^L produces the same effect, and even a normal ASCII letter.
- The position of the character on the line is irrelevant.
- That it is substituted by "\0" is relevant.

And now, the punchline:
- It does *not* happen with ClearType *on*.

Nice, isn't?

            Juanma

emacs.png
Description: PNG image