win32u: Remove no longer needed needs_unpack from win_proc_params.

dlls/user32/winproc.c

@@ -805,31 +805,27 @@ void unpack_message( HWND hwnd, UINT message, WPARAM *wparam, LPARAM *lparam,
 
 BOOL WINAPI User32CallWindowProc( struct win_proc_params *params, ULONG size )
 {
+    size_t packed_size = 0;
+    void *buffer = NULL;
     LRESULT result;
 
-    if (params->needs_unpack)
+    if (size > sizeof(*params))
     {
-        void *buffer;
+        const size_t offset = (sizeof(*params) + 15) & ~15;
+        packed_size = size - offset;
+        buffer = (char *)params + offset;
 
-        size -= sizeof(*params);
-        buffer = params + 1;
-
-        if (size)
-            unpack_message( params->hwnd, params->msg, &params->wparam,
-                            &params->lparam, buffer, size, params->ansi );
+        unpack_message( params->hwnd, params->msg, &params->wparam, &params->lparam,
+                        buffer, packed_size, params->ansi );
+    }
 
     result = dispatch_win_proc_params( params );
 
-        if (size)
+    if (packed_size)
     {
         LRESULT *result_ptr = (LRESULT *)buffer - 1;
         *result_ptr = result;
-            return NtCallbackReturn( result_ptr, sizeof(*result_ptr) + size, TRUE );
-        }
-    }
-    else
-    {
-        result = dispatch_win_proc_params( params );
+        return NtCallbackReturn( result_ptr, sizeof(*result_ptr) + packed_size, TRUE );
     }
     return NtCallbackReturn( &result, sizeof(result), TRUE );
 }

dlls/win32u/message.c

@@ -377,7 +377,6 @@ static BOOL init_win_proc_params( struct win_proc_params *params, HWND hwnd, UIN
     params->wparam = wparam;
     params->lparam = lparam;
     params->ansi = params->ansi_dst = ansi;
-    params->needs_unpack = FALSE;
     params->mapping = WMCHAR_MAP_CALLWINDOWPROC;
     params->dpi_awareness = get_window_dpi_awareness_context( params->hwnd );
     get_winproc_params( params, TRUE );
@@ -409,7 +408,6 @@ static BOOL init_window_call_params( struct win_proc_params *params, HWND hwnd,
     params->wparam = wParam;
     params->lparam = lParam;
     params->ansi = ansi;
-    params->needs_unpack = FALSE;
     params->mapping = mapping;
     params->dpi_awareness = get_window_dpi_awareness_context( params->hwnd );
     get_winproc_params( params, !is_dialog );
@@ -2155,10 +2153,10 @@ static LRESULT call_window_proc( HWND hwnd, UINT msg, WPARAM wparam, LPARAM lpar
 {
     struct win_proc_params p, *params = &p;
     BOOL ansi = ansi_dst && type == MSG_ASCII;
+    size_t packed_size = 0, offset = sizeof(*params);
     LRESULT result = 0;
     CWPSTRUCT cwp;
     CWPRETSTRUCT cwpret;
-    size_t packed_size = 0;
     void *ret_ptr;
     size_t ret_len = 0;
 
@@ -2177,7 +2175,12 @@ static LRESULT call_window_proc( HWND hwnd, UINT msg, WPARAM wparam, LPARAM lpar
     call_message_hooks( WH_CALLWNDPROC, HC_ACTION, same_thread, (LPARAM)&cwp, sizeof(cwp),
                         packed_size, ansi );
 
-    if (packed_size && !(params = malloc( sizeof(*params) + packed_size ))) return 0;
+    if (packed_size)
+    {
+        offset = (offset + 15) & ~15;
+        if (!(params = malloc( offset + packed_size ))) return 0;
+    }
+
     if (!init_window_call_params( params, hwnd, msg, wparam, lparam, ansi_dst, mapping ))
     {
         if (params != &p) free( params );
@@ -2185,11 +2188,10 @@ static LRESULT call_window_proc( HWND hwnd, UINT msg, WPARAM wparam, LPARAM lpar
     }
 
     if (type == MSG_OTHER_PROCESS) params->ansi = FALSE;
-    params->needs_unpack = packed_size != 0;
     if (packed_size)
-        pack_user_message( params + 1, packed_size, msg, wparam, lparam, ansi );
+        pack_user_message( (char *)params + offset, packed_size, msg, wparam, lparam, ansi );
 
-    result = dispatch_win_proc_params( params, sizeof(*params) + packed_size, &ret_ptr, &ret_len );
+    result = dispatch_win_proc_params( params, offset + packed_size, &ret_ptr, &ret_len );
     if (params != &p) free( params );
 
     copy_user_result( ret_ptr, min( ret_len, packed_size ), result, msg, wparam, lparam, ansi );

dlls/wow64win/user.c

@@ -353,7 +353,6 @@ struct win_proc_params32
     ULONG lparam;
     BOOL ansi;
     BOOL ansi_dst;
-    BOOL needs_unpack;
     enum wm_char_mapping mapping;
     ULONG dpi_awareness;
     ULONG procA;
@@ -471,7 +470,6 @@ static void win_proc_params_64to32( const struct win_proc_params *src, struct wi
     params.lparam = src->lparam;
     params.ansi = src->ansi;
     params.ansi_dst = src->ansi_dst;
-    params.needs_unpack = src->needs_unpack;
     params.mapping = src->mapping;
     params.dpi_awareness = HandleToUlong( src->dpi_awareness );
     params.procA = PtrToUlong( src->procA );
@@ -932,7 +930,7 @@ static NTSTATUS WINAPI wow64_NtUserCallWinProc( void *arg, ULONG size )
 {
     struct win_proc_params *params = arg;
     struct win_proc_params32 *params32 = arg;
-    size_t lparam_size = 0;
+    size_t lparam_size = 0, offset32 = sizeof(*params32);
     LRESULT result = 0;
     void *ret_ptr;
     ULONG ret_len;
@@ -940,11 +938,17 @@ static NTSTATUS WINAPI wow64_NtUserCallWinProc( void *arg, ULONG size )
 
     win_proc_params_64to32( params, params32 );
     if (size > sizeof(*params))
-        lparam_size = packed_message_64to32( params32->msg, params32->wparam, params + 1, params32 + 1,
-                                             size - sizeof(*params) );
+    {
+        const size_t offset64 = (sizeof(*params) + 15) & ~15;
+        offset32 = (offset32 + 15) & ~15;
+        lparam_size = packed_message_64to32( params32->msg, params32->wparam,
+                                             (char *)params + offset64,
+                                             (char *)params32 + offset32,
+                                             size - offset64 );
+    }
 
     status = Wow64KiUserCallbackDispatcher( NtUserCallWinProc, params32,
-                                            sizeof(*params32) + lparam_size,
+                                            offset32 + lparam_size,
                                             &ret_ptr, &ret_len );
 
     if (ret_len >= sizeof(LONG))

include/ntuser.h

@@ -149,7 +149,6 @@ struct win_proc_params
     LPARAM lparam;
     BOOL ansi;
     BOOL ansi_dst;
-    BOOL needs_unpack;
     enum wm_char_mapping mapping;
     DPI_AWARENESS_CONTEXT dpi_awareness;
     WNDPROC procA;