Fixes to skin drawing code, in case default.skn wasn't loaded on OS startup

Prevent creation of buttons with negative or zero width/height

git-svn-id: svn://kolibrios.org@54 a494cfbc-eb01-0410-851d-a64ba20cac60

kernel/trunk/gui/window.inc

@@ -316,7 +316,9 @@ display_settings:
      jne  no_com_colours
      mov  [windowtypechanged],dword 1
      mov  esi,[0x3010]
-     add  esi,[esi+0x10]
+     add  esi,0x10
+     add  ebx,[esi]
+     mov  esi,ebx
      mov  edi,common_colours
      and  ecx,127
      cld