user32: Return result through NtCallbackReturn for the thunk lock callback.

dlls/user.exe16/message.c

@@ -22,6 +22,8 @@
 #include <stdarg.h>
 #include <string.h>
 
+#include "ntstatus.h"
+#define WIN32_NO_STATUS
 #include "wine/winuser16.h"
 #include "wownt32.h"
 #include "winerror.h"
@@ -2587,16 +2589,17 @@ static void WINAPI User16CallFreeIcon( ULONG *param, ULONG size )
 }
 
 
-static DWORD WINAPI User16ThunkLock( DWORD *param, ULONG size )
+static NTSTATUS WINAPI User16ThunkLock( void *args, ULONG size )
 {
+    DWORD *param = args;
     if (size != sizeof(DWORD))
     {
         DWORD lock;
         ReleaseThunkLock( &lock );
-        return lock;
+        return NtCallbackReturn( &lock, sizeof(lock), STATUS_SUCCESS );
     }
     RestoreThunkLock( *param );
-    return 0;
+    return STATUS_SUCCESS;
 }
 
 

dlls/win32u/message.c

@@ -3007,12 +3007,15 @@ static inline LARGE_INTEGER *get_nt_timeout( LARGE_INTEGER *time, DWORD timeout
 static DWORD wait_message( DWORD count, const HANDLE *handles, DWORD timeout, DWORD mask, DWORD flags )
 {
     LARGE_INTEGER time;
-    DWORD ret, lock;
+    DWORD ret, lock = 0;
     void *ret_ptr;
     ULONG ret_len;
 
     if (enable_thunk_lock)
-        lock = KeUserModeCallback( NtUserThunkLock, NULL, 0, &ret_ptr, &ret_len );
+    {
+        if (!KeUserModeCallback( NtUserThunkLock, NULL, 0, &ret_ptr, &ret_len ) && ret_len == sizeof(lock))
+            lock = *(DWORD *)ret_ptr;
+    }
 
     if (user_driver->pProcessEvents( mask )) ret = count ? count - 1 : 0;
     else if (count)