user32: Add test cases for update rects affected by ShowWindow.

dlls/user32/tests/win.c

@@ -4162,6 +4162,42 @@ void test_gettext(void)
     UnregisterClass( clsname, NULL );
 }
 
+static void test_GetUpdateRect(void)
+{
+    RECT rc1, rc2;
+    HWND hgrandparent, hparent, hchild;
+
+    hgrandparent = CreateWindowA("static", "grandparent", WS_OVERLAPPEDWINDOW,
+                                 0, 0, 100, 100, NULL, NULL, 0, NULL);
+
+    hparent = CreateWindowA("static", "parent", WS_CHILD|WS_VISIBLE,
+                            0, 0, 100, 100, hgrandparent, NULL, 0, NULL);
+
+    hchild = CreateWindowA("static", "child", WS_CHILD|WS_VISIBLE,
+                            10, 10, 30, 30, hparent, NULL, 0, NULL);
+
+    ShowWindow(hgrandparent, SW_SHOW);
+    UpdateWindow(hgrandparent);
+
+    ShowWindow(hchild, SW_HIDE);
+    SetRect(&rc2, 0, 0, 0, 0);
+    GetUpdateRect(hgrandparent, &rc1, FALSE);
+    todo_wine
+    {
+        ok(EqualRect(&rc1, &rc2), "rects do not match (%d,%d,%d,%d) / (%d,%d,%d,%d)\n",
+                rc1.left, rc1.top, rc1.right, rc1.bottom,
+                rc2.left, rc2.top, rc2.right, rc2.bottom);
+    }
+
+    SetRect(&rc2, 10, 10, 40, 40);
+    GetUpdateRect(hparent, &rc1, FALSE);
+    ok(EqualRect(&rc1, &rc2), "rects do not match (%d,%d,%d,%d) / (%d,%d,%d,%d)\n",
+            rc1.left, rc1.top, rc1.right, rc1.bottom,
+            rc2.left, rc2.top, rc2.right, rc2.bottom);
+
+    DestroyWindow(hgrandparent);
+}
+
 START_TEST(win)
 {
     pGetAncestor = (void *)GetProcAddress( GetModuleHandleA("user32.dll"), "GetAncestor" );
@@ -4240,6 +4276,7 @@ START_TEST(win)
     test_SetWindowLong();
     test_ShowWindow();
     test_gettext();
+    test_GetUpdateRect();
 
     /* add the tests above this line */
     UnhookWindowsHookEx(hhook);