Re: [hober0@gmail.com: Re: mode-line redisplay bug]

[Jason Rumney <jasonr@gnu.org>]

"Richard M. Stallman" <rms@gnu.org> writes:

> His test case is very clear, but it does not fail when I try it.
> Can anyone else observe this failure?

I don't see this failure, but while trying to replicate it, I did see
some other display problems. I tried GNU/Linux and W32, I saw problems
on both when the mouse was over mouse-sensitive areas of the modeline,
but the symptoms were different.

If I hold the mouse above a mouse-sensitive part of the modeline while
switching buffers with C-c c as described in the original bug report,
I see the following:

On W32:

The highlighted portion of the modeline stays when the buffer
switches, overwriting any text that from the buffer that should appear
there. If I do the same in the header line of the *scratch* buffer, 
the entire header line is erased as it should be.

On GNU/Linux:

The highlit area flickers. On W32 it flickers once when the tooltip
pops up, but on X, it flickers constantly. I remember fixing something
like this on W32 years ago, it was in the code that detected mouse
movement - movement events were being sent for zero movement when
inside track-mouse forms. But my recollection is that the same bug did
not appear on X at the time, so even though the code appeared to be
the same, I did not try to apply my fix to the X code.

If C-c c is pressed before the tooltip pops up, nothing happens until
the tooltip-delay expires, then the tooltip flashes up for a brief
instant and the buffer switch takes place.

Both problems I saw on GNU/Linux appear in both the header-line and
mode-line.