Re: Tabs

[Ergus]

On Wed, Oct 09, 2019 at 05:21:15PM +0300, Eli Zaretskii wrote:
> > Date: Wed, 9 Oct 2019 15:55:39 +0200
> > From: Ergus <address@hidden>
> > Cc: address@hidden, address@hidden, address@hidden
> >
> > >If you set a breakpoint in this fragment from clear_garbaged_frames:
> > >
> > >      if (FRAME_VISIBLE_P (f) && FRAME_GARBAGED_P (f))
> > >        {
> > >          if ((f->resized_p || f->tab_bar_resized)
> > >              /* It makes no sense to redraw a non-selected TTY
> > >                 frame, since that will actually clear the
> > >                 selected frame, and might leave the selected
> > >                 frame with corrupted display, if it happens not
> > >                 to be marked garbaged.  */
> > >              && !(f != sf && (FRAME_TERMCAP_P (f) || FRAME_MSDOS_P (f))))
> > >            redraw_frame (f);  <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
> > >          else
> > >            clear_current_matrices (f);
> > >
> > >does the breakpoint fire after you type "C-x 6 f"?
> >
> > Yes:
> >
> > Thread 1 "emacs" hit Breakpoint 1, clear_garbaged_frames () at 
> > ../../src/xdisp.c:11805
> > 11805                   redraw_frame (f);
>
> So you are saying that the call to redraw_frame does nothing in your
> case?  It's supposed to clear out the entire X window and then cause
> its redisplay...
Exactly

> What about disabling double buffering, does it help in any way?
The same

> And what about the question I asked earlier about the last master
> build you had that didn't have this problem? do you have an answer?
I will look for it now.

> TIA.
>
> Anyway, Juri, I'm at the end of my wits (which evidently are too short
> to begin with) regarding this problem.  It is bad enough to have to
> debug this without being able to reproduce the problem on my machine,
> and in addition, I don't have a clear understanding how this is
> supposed to work.  AFAIU, you just copied the code from the tool-bar
> code, so it's possible that you don't understand that either.  Maybe
> Martin will be able to explain how the tool-bar related flags are
> supposed to work, and maybe that will help me see the light.  But I'm
> not holding my breath, given that even the call to redraw_frame
> doesn't seem to do what it's supposed to.
>
> Do you see the problem described by Jimmy on your system?  If so, are
> you able to debug it on your system (with my help, if you need it)?
> If not, would someone else who sees the problem please try debugging
> it?

This seems to be related with an optimization in redisplay as you said
because sometimes when I get the broken tab-bar if I scroll with the
mouse the bar scrolls too. (attached picture.) This happens with and
without double buffering.

Screenshot_2019-10-09_17-08-58.png
Description: PNG image