tdf#164072 vcl: Let MenuButton dispose its PopupMenu

The MenuButton usually owns the PopupMenu that
gets set via MenuButton::SetPopupMenu, but so far
didn't dispose it, i.e. the PopupMenu was never
disposed.

As far as I understand, that is a preexisting issue,
but since

commit 6708246e20ce522e673f539369cd38687d2dd16d
Author: Michael Weghorn <m.weghorn@posteo.de>
Date:   Thu Dec 5 11:06:48 2024 +0000

tdf#164093 tdf#157001 a11y: Improve menu window disposal

, not disposing the menu also means not disposing the
menu's MenuFloatingWindow (which gets created when the
popup menu shows), resulting in

warn:legacy.osl:563630:563630:vcl/source/window/window.cxx:307: Window ( 10MenuButton()) with live SystemWindows destroyed:  18MenuFloatingWindow()
Window ( 10MenuButton()) with live SystemWindows destroyed:  18MenuFloatingWindow()

and an assert getting triggered as mentioned in
tdf#164072 comment 16.

Fix this by letting the MenuButton take care of
disposing the menu if it is the owner.

The only case where the MenuButton is assigned a menu
without taking ownership is in
SalInstanceComboBox::set_item_menu (which currently only
gets called from SvxStyleBox_Base::SetupEntry).
In that case, the weld::Menu passed to
SalInstanceComboBox::set_item_menu has the ownership:
SalInstanceBuilder::weld_menu calls the
SalInstanceMenu ctor with a bTakeOwnership=true,
and the SalInstanceMenu dtor disposes the menu.

Add a `bTakeOwnership` bool param to MenuButton::SetPopupMenu
to distinguish between the cases where the PopupMenu
is responsible for disposing the menu and where it's not.

Change-Id: I32766d5084e4826056ef394a587b8c2e3124c4da
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/178197
Tested-by: Jenkins
Reviewed-by: Michael Weghorn <m.weghorn@posteo.de>

1 files changed, 7 insertions, 1 deletions

diff --git a/vcl/source/control/menubtn.cxx b/vcl/source/control/menubtn.cxx
index 28417879888d..1cfd0799fe30 100644
--- a/vcl/source/control/menubtn.cxx
+++ b/vcl/source/control/menubtn.cxx
@@ -166,6 +166,8 @@ void MenuButton::dispose()
 {
     mpMenuTimer.reset();
     mpFloatingWindow.clear();
+    if (mpMenu && mbOwnPopupMenu)
+        mpMenu->dispose();
     mpMenu.clear();
     PushButton::dispose();
 }
@@ -240,12 +242,16 @@ void MenuButton::Select()
     maSelectHdl.Call( this );
 }
 
-void MenuButton::SetPopupMenu(PopupMenu* pNewMenu)
+void MenuButton::SetPopupMenu(PopupMenu* pNewMenu, bool bTakeOwnership)
 {
     if (pNewMenu == mpMenu)
         return;
 
+    if (mpMenu && mbOwnPopupMenu)
+        mpMenu->dispose();
+
     mpMenu = pNewMenu;
+    mbOwnPopupMenu = bTakeOwnership;
 }
 
 void MenuButton::SetPopover(Window* pWindow)