lpCreateParams should be a SEGPTR in 16-bit code.

dlls/user/hook16.c

@@ -222,7 +222,7 @@ static LRESULT CALLBACK call_WH_CBT( INT code, WPARAM wp, LPARAM lp )
             CBT_CREATEWND16 cbtcw16;
             CREATESTRUCT16 cs16;
 
-            cs16.lpCreateParams = cbtcw32->lpcs->lpCreateParams;
+            cs16.lpCreateParams = (SEGPTR)cbtcw32->lpcs->lpCreateParams;
             cs16.hInstance      = HINSTANCE_16(cbtcw32->lpcs->hInstance);
             cs16.hMenu          = HMENU_16(cbtcw32->lpcs->hMenu);
             cs16.hwndParent     = HWND_16(cbtcw32->lpcs->hwndParent);
@@ -525,7 +525,7 @@ LRESULT WINAPI CallNextHookEx16( HHOOK hhook, INT16 code, WPARAM16 wparam, LPARA
                 cbtcw32.lpcs = &cs32;
                 cbtcw32.hwndInsertAfter = WIN_Handle32( cbtcw16->hwndInsertAfter );
 
-                cs32.lpCreateParams = cs16->lpCreateParams;
+                cs32.lpCreateParams = (LPVOID)cs16->lpCreateParams;
                 cs32.hInstance      = HINSTANCE_32(cs16->hInstance);
                 cs32.hMenu          = HMENU_32(cs16->hMenu);
                 cs32.hwndParent     = WIN_Handle32(cs16->hwndParent);

include/wine/winuser16.h

@@ -275,7 +275,7 @@ typedef struct /* not sure if the 16bit version is correct */
 
 typedef struct
 {
-    LPVOID      lpCreateParams;
+    SEGPTR      lpCreateParams;
     HINSTANCE16 hInstance;
     HMENU16     hMenu;
     HWND16      hwndParent;

windows/struct32.c

@@ -90,7 +90,7 @@ void STRUCT32_WINDOWPOS16to32( const WINDOWPOS16* from, WINDOWPOS* to )
 void STRUCT32_CREATESTRUCT32Ato16( const CREATESTRUCTA* from,
                                    CREATESTRUCT16* to )
 {
-    to->lpCreateParams = from->lpCreateParams;
+    to->lpCreateParams = (SEGPTR)from->lpCreateParams;
     to->hInstance      = HINSTANCE_16(from->hInstance);
     to->hMenu          = HMENU_16(from->hMenu);
     to->hwndParent     = HWND_16(from->hwndParent);
@@ -105,7 +105,7 @@ void STRUCT32_CREATESTRUCT32Ato16( const CREATESTRUCTA* from,
 void STRUCT32_CREATESTRUCT16to32A( const CREATESTRUCT16* from,
                                    CREATESTRUCTA *to )
 {
-    to->lpCreateParams = from->lpCreateParams;
+    to->lpCreateParams = (LPVOID)from->lpCreateParams;
     to->hInstance      = HINSTANCE_32(from->hInstance);
     to->hMenu          = HMENU_32(from->hMenu);
     to->hwndParent     = WIN_Handle32(from->hwndParent);
@@ -141,4 +141,3 @@ void STRUCT32_MDICREATESTRUCT16to32A( const MDICREATESTRUCT16* from,
     to->style  = from->style;
     to->lParam = from->lParam;
 }
-