Another redisplay error in emacs HEAD.

Another redisplay error in emacs HEAD.

[Kim F. Storm]

The following happens with today's HEAD (but it also happens with a
version that I built from CVS on Oct 18), and it happens both under X
and with -nw in an xterm.  I'm running on GNU/Linux (tried on both red
hat 6.2 and 7.3).

Save the following text in a file (let's call it emacs-bug) and follow
these steps:

In an xterm window (at least 80 chars wide), do:

1) start emacs -q -no-site-file -nw

2) load the file emacs-bug into the sole window.

3) drag the bottom border of the xterm frame to resize the
   emacs window to make it exactly 17 lines high; the 
   'aaaa -- this should be on the last window line' should be
   at the bottom of the window.

4) place the cursor at the beginning of the second line
   (the first 'aaaa' line).

5) define a keyboard macro which moves down to the 'bbbb' line (C-n),
   deletes it (C-k C-k), and then moves down to the start of the next
   'aaaa' line (C-n C-n C-n), i.e.

        C-x ( C-n C-k C-k C-n C-n C-n C-x )

6) now execute the macro exactly 5 times

        C-x e e e e e

7) notice the odd position of the cursor; it is at the end
   of the [xx] line rather than at the start of the following
   'aaaa' line.   Moving the cursor right (C-f) moves it to
   the second 'a' on the next line, so emacs thinks that the cursor
   is in the "expected" position.

I suppose it has something to do with the cursor ending up on
the last window line [so the window should have scrolled, but
didn't].


Here is the file (don't include the 'cut here' lines!!!):

---------------------8<-------------- cut here ------------
[xx]  1) Adjust the window height to 17 lines [the bottom line is 'aaaa --']
aaaa  2) Move the cursor to the beginning of this line
bbbb  
cccc  3) Enter: C-x ( C-n C-k C-k C-n C-n C-n C-x )

[xx]
aaaa  4) The cursor should be at this line.
bbbb  5) Execute the keyboard macro 5 times C-x e e e e e
cccc

[xx]
aaaa
bbbb
cccc

[xx]
aaaa -- this should be on the last window line
bbbb
cccc

[xx]
aaaa
bbbb
cccc

[xx]
aaa +--------- cursor is now here
bbb |
ccc |
    v
[xx]
aaaa
bbbb
cccc

[xx]
aaaa
bbbb
cccc
---------------------8<-------------- cut here ------------


-- 
Kim F. Storm <storm@cua.dk> http://www.cua.dk