Bug#1128961: xterm: selection not fully cleared after text changes

On Mon, Apr 20, 2026 at 10:05:24AM +0200, Vincent Lefevre wrote:
> On 2026-04-19 09:29:07 -0400, Thomas Dickey wrote:
> > On Sun, Apr 19, 2026 at 03:18:28AM +0200, Vincent Lefevre wrote:
> [...]
> > > But note that the <Down> key makes Mutt display a different mail
> > > message. It happens that there are common lines, but this is just a
> > > coincidence. So it is quite strange that this is seen as a scroll.
> > > This may be an issue coming from ncurses.
> > 
> > no -- ncurses can't tell if xterm (or any other terminal) has a selection
> > highlighted.
> 
> Sure, but I don't see why there is a scrolling involved and why,
> when going to the next or previous Mutt message, the effect on
> the selection is inconsistent.

ncurses is given an old/current and new/desired screen contents, and
writes the updated screen using as few characters as possible (within
its repertoire of course).  So it may move text that's already on the
screen if moving it takes fewer characters than writing it again.

-- 
Thomas E. Dickey <[email protected]>
https://invisible-island.net

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