Enable creation of a zbuffer in system memory.

dlls/ddraw/ddraw/main.c

@@ -631,17 +631,18 @@ Main_DirectDraw_CreateSurface(LPDIRECTDRAW7 iface, LPDDSURFACEDESC2 pDDSD,
 	/* create texture */
 	hr = create_texture(This, pDDSD, ppSurf, pUnkOuter);
     }
+    else if ( (pDDSD->ddsCaps.dwCaps & DDSCAPS_ZBUFFER) &&
+	     !(pDDSD->ddsCaps.dwCaps & DDSCAPS_OFFSCREENPLAIN)) /* Support DDSCAPS_SYSTEMMEMORY */
+    {
+	/* create z-buffer */
+	hr = This->create_zbuffer(This, pDDSD, ppSurf, pUnkOuter);
+    }
     else if ((pDDSD->ddsCaps.dwCaps & DDSCAPS_OFFSCREENPLAIN) ||
 	     (pDDSD->ddsCaps.dwCaps & DDSCAPS_SYSTEMMEMORY)) /* No difference in Wine right now */
     {
 	/* create offscreenplain surface */
 	hr = create_offscreen(This, pDDSD, ppSurf, pUnkOuter);
     }
-    else if (pDDSD->ddsCaps.dwCaps & DDSCAPS_ZBUFFER)
-    {
-	/* create z-buffer */
-	hr = This->create_zbuffer(This, pDDSD, ppSurf, pUnkOuter);
-    }
     else
     {
 	/* Otherwise, assume offscreenplain surface */