user32: Add support for RTL window layouts in GetUpdateRgn and GetUpdateRect.

dlls/user32/painting.c

@@ -1289,8 +1289,6 @@ INT WINAPI GetUpdateRgn( HWND hwnd, HRGN hrgn, BOOL erase )
 
     if ((update_rgn = send_ncpaint( hwnd, NULL, &flags )))
     {
-        POINT offset;
-
         retval = CombineRgn( hrgn, update_rgn, 0, RGN_COPY );
         if (send_erase( hwnd, flags, update_rgn, NULL, NULL ))
         {
@@ -1298,9 +1296,7 @@ INT WINAPI GetUpdateRgn( HWND hwnd, HRGN hrgn, BOOL erase )
             get_update_flags( hwnd, NULL, &flags );
         }
         /* map region to client coordinates */
-        offset.x = offset.y = 0;
-        ScreenToClient( hwnd, &offset );
-        OffsetRgn( hrgn, offset.x, offset.y );
+        map_window_region( 0, hwnd, hrgn );
     }
     return retval;
 }
@@ -1324,8 +1320,10 @@ BOOL WINAPI GetUpdateRect( HWND hwnd, LPRECT rect, BOOL erase )
         if (GetRgnBox( update_rgn, rect ) != NULLREGION)
         {
             HDC hdc = GetDCEx( hwnd, 0, DCX_USESTYLE );
+            DWORD layout = SetLayout( hdc, 0 );  /* MapWindowPoints mirrors already */
             MapWindowPoints( 0, hwnd, (LPPOINT)rect, 2 );
             DPtoLP( hdc, (LPPOINT)rect, 2 );
+            SetLayout( hdc, layout );
             ReleaseDC( hwnd, hdc );
         }
     }

dlls/user32/win.h

@@ -83,6 +83,7 @@ extern HWND WIN_IsCurrentThread( HWND hwnd ) DECLSPEC_HIDDEN;
 extern HWND WIN_SetOwner( HWND hwnd, HWND owner ) DECLSPEC_HIDDEN;
 extern ULONG WIN_SetStyle( HWND hwnd, ULONG set_bits, ULONG clear_bits ) DECLSPEC_HIDDEN;
 extern BOOL WIN_GetRectangles( HWND hwnd, enum coords_relative relative, RECT *rectWindow, RECT *rectClient ) DECLSPEC_HIDDEN;
+extern void map_window_region( HWND from, HWND to, HRGN hrgn ) DECLSPEC_HIDDEN;
 extern LRESULT WIN_DestroyWindow( HWND hwnd ) DECLSPEC_HIDDEN;
 extern void WIN_DestroyThreadWindows( HWND hwnd ) DECLSPEC_HIDDEN;
 extern HWND WIN_CreateWindowEx( CREATESTRUCTW *cs, LPCWSTR className, HINSTANCE module, BOOL unicode ) DECLSPEC_HIDDEN;

dlls/user32/winpos.c

@@ -501,6 +501,41 @@ static POINT WINPOS_GetWinOffset( HWND hwndFrom, HWND hwndTo, BOOL *mirrored )
     return offset;
 }
 
+/* map coordinates of a window region */
+void map_window_region( HWND from, HWND to, HRGN hrgn )
+{
+    BOOL mirrored;
+    POINT offset = WINPOS_GetWinOffset( from, to, &mirrored );
+    UINT i, size;
+    RGNDATA *data;
+    HRGN new_rgn;
+    RECT *rect;
+
+    if (!mirrored)
+    {
+        OffsetRgn( hrgn, offset.x, offset.y );
+        return;
+    }
+    if (!(size = GetRegionData( hrgn, 0, NULL ))) return;
+    if (!(data = HeapAlloc( GetProcessHeap(), 0, size ))) return;
+    GetRegionData( hrgn, size, data );
+    rect = (RECT *)data->Buffer;
+    for (i = 0; i < data->rdh.nCount; i++)
+    {
+        int tmp = -(rect[i].left + offset.x);
+        rect[i].left    = -(rect[i].right + offset.x);
+        rect[i].right   = tmp;
+        rect[i].top    += offset.y;
+        rect[i].bottom += offset.y;
+    }
+    if ((new_rgn = ExtCreateRegion( NULL, data->rdh.nCount, data )))
+    {
+        CombineRgn( hrgn, new_rgn, 0, RGN_COPY );
+        DeleteObject( new_rgn );
+    }
+    HeapFree( GetProcessHeap(), 0, data );
+}
+
 
 /*******************************************************************
  *		MapWindowPoints (USER32.@)