[Bug-AUCTeX] preview oddity when "merging" inline formulas...

[Evil Boris]

In a LaTeX document, write something like

   and this depends on $x$ and $y$ MORE TEXT MORE TEXT MORE TEXT MORE
   TEXT MORE TEXT MORE TEXT MORE TEXT MORE TEXT

preview, say using C-c C-p C-d (or C-c C-p C-p).  Now move the cursor
to the $ just after x and type C-d a few times and then a comma,
obtaining

   and this depends on $x, y$ MORE TEXT MORE TEXT MORE TEXT MORE
   TEXT MORE TEXT MORE TEXT MORE TEXT MORE TEXT

with the cursor someplace around the comma.  Notice that there are two
preview-generated pictures around [can't really tell what they are
supposed to represent, too small for my eye sight], which is annoying
but understandable.  If I type C-c C-p C-p now, everything after the
$x,y$ disappears from the display!  Very disconcerting, especially the
first time it happens.  C-c C-p C-d makes everything peachy again.

That's recent snapshot AUCTeX (but noticed the same problem a few
months ago) and CVS Emacs.

--Boris