Re: redundant redisplay

[David Kastrup]

Tak Ota <address@hidden> writes:

> Some recent change, which I cannot identify, affects the redisplay
> mechanism so that set-buffer-modified-p redisplays window contents
> redundantly.  It creates occasional annoying partial screen flashing
> as well as considerably slows down a buffer process which updates
> modeline frequently.

>From the Elisp manual:

 - Function: set-buffer-modified-p flag
     This function marks the current buffer as modified if FLAG is
     non-`nil', or as unmodified if the flag is `nil'.

     Another effect of calling this function is to cause unconditional
     redisplay of the mode line for the current buffer.  In fact, the
     function `force-mode-line-update' works by doing this:

          (set-buffer-modified-p (buffer-modified-p))

So it _should_ cause a redisplay, but only of the buffer line.  Kim,
are you taking a peek at the line height there, could that be it?

-- 
David Kastrup, Kriemhildstr. 15, 44793 Bochum