Second attempt at fixing #19335: holding down backspace in the

text editor creates squares on some systems. Based on info from
Martin, it appears the keymodifier is being set when it shouldn't.
I think this is happening become some systems may be generating
KM_PRESS events without a matching KM_RELEASE?

Also ignore ascii values 1-32 now instead of 14-32, not sure why
they were included now in 2.5 because they were not in 2.4, but
I don't see a reason to do it. This fixes squares when pressing
e.g. ctrl+b or ctrl+n.

source/blender/windowmanager/intern/wm_event_system.c

@@ -1600,7 +1600,7 @@ void wm_event_add_ghostevent(wmWindow *win, int type, void *customdata)
 			event.val= (type==GHOST_kEventKeyDown)?KM_PRESS:KM_RELEASE;
 			
 			/* exclude arrow keys, esc, etc from text input */
-			if(type==GHOST_kEventKeyUp || (event.ascii<32 && event.ascii>14))
+			if(type==GHOST_kEventKeyUp || (event.ascii<32 && event.ascii>0))
 				event.ascii= '\0';
 			
 			/* modifiers */
@@ -1630,6 +1630,13 @@ void wm_event_add_ghostevent(wmWindow *win, int type, void *customdata)
 				else if(event.val==KM_RELEASE && event.keymodifier==event.type)
 					event.keymodifier= evt->keymodifier= 0;
 			}
+
+			/* this case happens on some systems that on holding a key pressed,
+			   generate press events without release, we still want to keep the
+			   modifier in win->eventstate, but for the press event of the same
+			   key we don't want the key modifier */
+			if(event.keymodifier == event.type)
+				event.keymodifier= 0;
 			
 			/* if test_break set, it catches this. XXX Keep global for now? */
 			if(event.type==ESCKEY)