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

On 2026-04-18 12:21:25 -0400, Thomas Dickey wrote:
> On Fri, Apr 17, 2026 at 03:35:17PM +0200, Vincent Lefevre wrote:
> > On 2026-04-14 03:38:55 -0400, Thomas Dickey wrote:
> > > fixed in #409
> > 
> > Thanks, this has much improved, but the behavior is still strange.
> > For instance, after selecting the full body
> > 
> > ----------------------------------------
> > z
> > 
> > 1234
> > 123456
> > 12345678
> > 1234567
> > 12
> > 
> > 123456
> > 1234
> > 12
> > ----------------------------------------
> > 
> > and typing the <Down> key, the first two lines ("z" and the blank
> > line that follows) are still selected. In case this is regarded
> > as an expected behavior to keep a common part of the selection,
> > this is inconsistent, because when I type the <Up> key to go back
> > to the first message, the selection is entirely cleared.
> 
> That's "expected behavior".  In the example you reported, ncurses is
> setting a scrolling region in the middle of the screen.  It does that
> to move some lines up or down - and the selection moved with the text.

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.