Jinoh Kang : server: Update parent window region when exposing previously invisible window.

[Alexandre Julliard]

Module: wine
Branch: master
Commit: 078b0219aa4a3ead156e94b5d31202d58b0bb504
URL:    https://gitlab.winehq.org/wine/wine/-/commit/078b0219aa4a3ead156e94b5d31202d...

Author: Jinoh Kang <jinoh.kang.kr(a)gmail.com>
Date:   Sat May 20 23:20:36 2023 +0900

server: Update parent window region when exposing previously invisible window.

Fixes: 33617af8145b6fadfe41d48968a728ff57b3064b
Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=54949

---

 dlls/user32/tests/msg.c | 8 +-------
 server/window.c         | 5 +++--
 2 files changed, 4 insertions(+), 9 deletions(-)

diff --git a/dlls/user32/tests/msg.c b/dlls/user32/tests/msg.c
index 5caf845d215..a7c1cf802e0 100644
--- a/dlls/user32/tests/msg.c
+++ b/dlls/user32/tests/msg.c
@@ -5793,7 +5793,7 @@ static void test_messages(void)
     test_WM_SETREDRAW(hchild);
 
     ShowWindow(hchild, SW_SHOW);
-    ok_sequence(WmShowChildSeq, "ShowWindow(SW_SHOW):child", TRUE);
+    ok_sequence(WmShowChildSeq, "ShowWindow(SW_SHOW):child", FALSE);
 
     /* check parent messages too */
     log_all_parent_messages++;
@@ -9467,12 +9467,10 @@ static void test_swp_paint_region_on_show(void)
         "GetUpdateRgn on child shall succeed\n" );
 
     result = GetRgnBox( hrgn_actual, &rect_actual );
-    todo_wine_if (result == NULLREGION)
     ok( result == SIMPLEREGION, "GetRgnBox (on parent) returned %d\n", result );
     if (result == COMPLEXREGION) dump_region( hrgn_actual );
 
     rect_expect = rect_1;
-    todo_wine_if (IsRectEmpty( &rect_actual ))
     ok( EqualRect( &rect_actual, &rect_expect ), "parent update region: got %s, expected %s\n",
         wine_dbgstr_rect( &rect_actual ), wine_dbgstr_rect( &rect_expect ) );
 
@@ -9506,12 +9504,10 @@ static void test_swp_paint_region_on_show(void)
         "GetUpdateRgn on child shall succeed\n" );
 
     result = GetRgnBox( hrgn_actual, &rect_actual );
-    todo_wine_if (result == NULLREGION)
     ok( result == SIMPLEREGION, "GetRgnBox (on parent) returned %d\n", result );
     if (result == COMPLEXREGION) dump_region( hrgn_actual );
 
     rect_expect = rect_2;
-    todo_wine_if (IsRectEmpty( &rect_actual ))
     ok( EqualRect( &rect_actual, &rect_expect ), "parent update region: got %s, expected %s\n",
         wine_dbgstr_rect( &rect_actual ), wine_dbgstr_rect( &rect_expect ) );
 
@@ -9565,12 +9561,10 @@ static void test_swp_paint_region_on_extend_zerosize(void)
         "GetUpdateRgn on child shall succeed\n" );
 
     result = GetRgnBox( hrgn_actual, &rect_actual );
-    todo_wine_if (result == NULLREGION)
     ok( result == SIMPLEREGION, "GetRgnBox (on parent) returned %d\n", result );
     if (result == COMPLEXREGION) dump_region( hrgn_actual );
 
     rect_expect = rect_1;
-    todo_wine_if (IsRectEmpty( &rect_actual ))
     ok( EqualRect( &rect_actual, &rect_expect ), "parent update region: got %s, expected %s\n",
         wine_dbgstr_rect( &rect_actual ), wine_dbgstr_rect( &rect_expect ) );
 
diff --git a/server/window.c b/server/window.c
index f713ed224aa..01082b90b69 100644
--- a/server/window.c
+++ b/server/window.c
@@ -1766,8 +1766,9 @@ static struct region *expose_window( struct window *win, const rectangle_t *old_
         offset_region( new_vis_rgn, win->window_rect.left - old_window_rect->left,
                        win->window_rect.top - old_window_rect->top  );
 
-        if (is_composited ? union_region( new_vis_rgn, old_vis_rgn, new_vis_rgn )
-                          : subtract_region( new_vis_rgn, old_vis_rgn, new_vis_rgn ))
+        if (is_region_empty( old_vis_rgn ) ||
+            (is_composited ? union_region( new_vis_rgn, old_vis_rgn, new_vis_rgn )
+                           : subtract_region( new_vis_rgn, old_vis_rgn, new_vis_rgn )))
         {
             if (!is_region_empty( new_vis_rgn ))
             {