Fix TAB navigation in wxGTK broken by r72663.

Don't call SetCanFocus(true) for container windows with focusable children,
this doesn't play well at all with wxGTK focus handling and in particular
totally disabled TAB navigation.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@73018 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/common/containr.cpp

@@ -54,7 +54,10 @@ bool wxControlContainerBase::UpdateCanFocusChildren()
     {
         m_acceptsFocusChildren = acceptsFocusChildren;
 
-        m_winParent->SetCanFocus(AcceptsFocusRecursively());
+        // In the ports where it does something non trivial, the parent window
+        // should only be focusable if it doesn't have any focusable children
+        // (e.g. native focus handling in wxGTK totally breaks down otherwise).
+        m_winParent->SetCanFocus(m_acceptsFocusSelf && !m_acceptsFocusChildren);
     }
 
     return m_acceptsFocusChildren;