addressed by the "Window resizing" patch.
A fair amount of detail about the problem can be found on the bug:
http://bugs.winehq.com/show_bug.cgi?id=1265
Visual Foxpro displays several things like tooltips by creating internal hDCs, drawing into the internal hDC, and then copying the hDC to the screen hDC.
To display the tooltip, it calls MoveWindow followed immediately by SetWindowPos to resize both the internal hDC and the screen hDC. This causes two X ConfigureNotify events to be generated. VFP really did not need to call MoveWindow on the internal hDC, and this leads to the problem, though it really just exposes a problem in how Wine handles a sequence of sizes and moves on a window.
The event handler (X11DRV_ConfigureNotify) for the first event notices that the current window size is different from the size in the event message, and resizes the window back to the original size! The second event sees that the window is again the wrong size, and resizes the window once again to the correct size. At this point, the only valid portion of the window is the intersection of the two rectangles.
For a normal window, exposure events would then cause the invalid window contents to be repainted, thus covering up all this extra resizing. However, for an offscreen hDC, no application is going to have a method for repainting, because there is no reason for the offscreen image to become corrupted. And indeed in Visual Foxpro, that is all that gets painted into the tooltip (the rest has only the background painted).
The solution of course is that before sizing or moving a window, all pending X ConfigureNotify events should be processed. Hopefully I am not violating DLL separation here (I still have not really figured that part out).
Changelog:
Before changing window size/pos, handle pending ConfigureNotify events.
Index: dlls/x11drv/winpos.c
===================================================================
RCS file: /home/wine/wine/dlls/x11drv/winpos.c,v
retrieving revision 1.63
diff -u -r1.63 winpos.c
--- dlls/x11drv/winpos.c 8 Jan 2003 21:09:26 -0000 1.63
+++ dlls/x11drv/winpos.c 10 Feb 2003 22:33:20 -0000
@@ -887,6 +887,9 @@
UINT wvrFlags = 0;
BOOL bChangePos;
+ /* This is needed to flush pending X ConfigureNotify events on this window */
+ MsgWaitForMultipleObjectsEx( 0, NULL, 0, 0, 0 );
+
TRACE( "hwnd %p, swp (%i,%i)-(%i,%i) flags %08x\n",
winpos->hwnd, winpos->x, winpos->y,
winpos->x + winpos->cx, winpos->y + winpos->cy, winpos->flags);
