Mixed-height lines & partially displayed cursor

[Thomas Morgan <tlm@pocketmail.com>]

Execute `xrdb -remove', then run GNU Emacs 21.3.50.5
(i686-pc-linux-gnu, X toolkit, Xaw3d scroll bars) of 2002-09-09
with the options -q --no-site-file --geometry=80x12.

The geometry must be 80x12 for this test case.  (That is the correct
value when it is specified on the command line.  However, I am using
the Sawfish window manager, and if I start to resize the frame,
a box appears which indicates that the current size is 84x14.)

Type this sexp in *scratch*.

  (let ((line "lose\n"))
    (erase-buffer)
    (insert line)
    (set-text-properties 0 (length line) '(face (:height 1.2)) line)
    (insert line))

Evaluate it with C-x C-e.  Now the window looks like this:

   lose
   *lose*
   -!-

(I use *stars* to show a larger face, and -!- to represent the cursor.)

Type C-x 2.  The window splits into two, and the cursor is partially
visible on the third line of the top window.  It is invisible in the
bottom window.

In a moment, the two loses become three, like this:

   lose *lose*
   *lose*-!-
   --:**  *scratch*    Bot L3
   lose *lose*
   *lose*
   -!-
   --:**  *scratch*    All L3

Is this the right mailing list for bug reports about the development
version of Emacs?  Or is it better not to report bugs in that version?