[10521] in Athena Bugs
RS/6000 GTO clipping region bug
daemon@ATHENA.MIT.EDU (John Carr)
Sun May 30 17:49:10 1993
To: bugs@Athena.MIT.EDU
Cc: phils@Athena.MIT.EDU
Date: Sun, 30 May 1993 17:49:04 EDT
From: John Carr <jfc@Athena.MIT.EDU>
The RS/6000 GTO X server (machtype -d says "hispd3d : 7235 POWER GTO")
has a bug recalculating clip regions after a window is resized.
To reproduce:
Set up an xterm window so that it is partially overlapped along one
edge by another window. Note it is important that the exposed area at
this point not be a rectangle. It needs to look like this:
+-----+----+
| a | c |
| +-+--+
| b |
| |
+-------+
Region c is the obscuring window. Regions a and b are the xterm.
Fill the xterm with text. Now turn the scrollbar on then off again.
Only the region of the xterm above the lower edge of the obscuring
window will be redrawn (region "a" in the diagram). This is a bug in
the server clipping code, not xterm, because asking xterm to redraw
the window has no effect and new text in the xterm will not appear if
it is in the blank region. (Note that "xrefresh" will work because it
maps a window over xterm then unmaps it, but the built in redraw()
action will not work.)
I use xterm with these key bindings which were helpful in my
experimenting:
XTerm*VT100.translations: #override\
<Key>Home: redraw() \n\
<Key>End: set-scrollbar(toggle)
This bins the End key to turn the scrollbar on and off and the Home
key to redraw the window.
