Re: xterm.c (x_clear_frame) - commented out call to XClearWindow

["Jan Djärv" <jan.h.d@swipnet.se>]

22 nov 2011 kl. 06:31 skrev Chong Yidong:

> Jan Djärv <jan.h.d@swipnet.se> writes:
> 
>> The uncommented XClearWindow in x_clear_frame must be there so I
>> activated it again...  Flickering is almost unavoidable for Gtk as we
>> bypass the normal Gtk drawing stuff.
> 
> Obviously, I disagree.  AFAICT this has nothing to do with GTK.

That depends on what you mean with "this".

> 
> The XClearWindow is obviously unnecessary if Emacs covers the entire
> frame area when drawing glyph strings during redisplay, since the glyph
> strings apply the background color.  The problem here arises because
> there are some areas of the frame not drawn over durig redisplay,
> e.g. the leftover spaces to the bottom and right in fullscreen mode.
> The fact that these areas are unpainted may be regarded as a bug.  A
> suitable temporary work-around would be to paint over them---but
> painting the entire frame is clearly an overreach.

It would be nice if we could just fix ther leftover spaces.  But I think it is too long in to pretest to fix this.  You have to first find all leftover spaces (i.e. under/between scroll bars, minibuffer, fringe) in all cases (font size not a multiple of frame size, fullscreen, and so on) and in all configurations (lucid, Gtk, just X, motif, with or without native scrollbars, with or without Xaw3d scrollbars).
And then for different environments, some redraw errors only appears with XFCE, some with Gnome-shell.

	Jan D.