Related: tdf#92392 clear workwins that point to pWindow

before trying to destroy pWindow

Change-Id: I7257096e8da2a5d6753ad2091287d63ea9ae244b
(cherry picked from commit 3c6eec0d)
Reviewed-on: https://gerrit.libreoffice.org/16832Reviewed-by: Miklos Vajna <vmiklos@collabora.co.uk>
Tested-by: Miklos Vajna <vmiklos@collabora.co.uk>

include/sfx2/childwin.hxx

@@ -163,6 +163,8 @@ private:
                         GetContext() const
                         { return pContext; }
 
+    SAL_DLLPRIVATE void ClearWorkwin();
+
 protected:
                         SfxChildWindow(vcl::Window *pParentWindow, sal_uInt16 nId);
 

sfx2/source/appl/childwin.cxx

@@ -177,12 +177,7 @@ void SfxChildWindow::Destroy()
 {
     if ( GetFrame().is() )
     {
-        if (pImp->pWorkWin)
-        {
-            if (pImp->pWorkWin->GetActiveChild_Impl() == pWindow)
-                pImp->pWorkWin->SetActiveChild_Impl(NULL);
-            pImp->pWorkWin = NULL;
-        }
+        ClearWorkwin();
         try
         {
             ::com::sun::star::uno::Reference < ::com::sun::star::util::XCloseable > xClose( GetFrame(), ::com::sun::star::uno::UNO_QUERY );
@@ -199,11 +194,21 @@ void SfxChildWindow::Destroy()
         delete this;
 }
 
+void SfxChildWindow::ClearWorkwin()
+{
+    if (pImp->pWorkWin)
+    {
+        if (pImp->pWorkWin->GetActiveChild_Impl() == pWindow)
+            pImp->pWorkWin->SetActiveChild_Impl(NULL);
+        pImp->pWorkWin = NULL;
+    }
+}
 
 SfxChildWindow::~SfxChildWindow()
 {
     delete pContext;
     pContext = NULL;
+    ClearWorkwin();
     pWindow.disposeAndClear();
     delete pImp;
     pImp = NULL;