http://bugs.winehq.org/show_bug.cgi?id=5300
------- Additional Comments From marcus@jet.franken.de 2006-28-05 09:28 ------- after studying x server code this error can only happen if the format we send is not correct and has either more glyphs than data or more data than glyphs.
xc/programs/Xserver/render/render.c:
if (nglyphs || remain) { err = BadLength; goto bail; }