Don't know where to file against, thus parking at gnome-desktop until it's
narrowed down further.
The following test was done with gedit, but everything applies to random GTK
entry widgets. It's not gedit/gtk-sourceview related. From my understanding the
problem can be isolated to pango(?), or cairo.
System is up to date rawhide ppc.
1. Open gedit and make sure text wrapping is disabled.
2. Write some text into a single line. With Bitstream Vera Sans Mono at 10pt
it's for me 4098 times the character "c". Text will disappear, cursor is visible.
3. Change the font size to 8pt. The text will reappear.
4. Write some more "c". At count 5463 the text will disappear again.
this is a limitation of GtkTextView. There is an upstream bug at
bugzilla.gnome.org about it, but the chances of fixing this are