modeling subclassing along msw, unsubclassing filedialog at end of ShowModal, fixes #12236

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@65474 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/osx/cocoa/filedlg.mm

@@ -275,6 +275,7 @@ int wxFileDialog::ShowModal()
         returnCode = [sPanel runModalForDirectory:dir.AsNSString() file:file.AsNSString() ];
         ModalFinishedCallback(sPanel, returnCode);
 
+        UnsubclassWin();
         [sPanel setAccessoryView:nil];
     }
     else
@@ -295,6 +296,7 @@ int wxFileDialog::ShowModal()
 
         ModalFinishedCallback(oPanel, returnCode);
         
+        UnsubclassWin();
         [oPanel setAccessoryView:nil];
         
         if ( types != nil )