Prevent downcast to SwTxtFrm when already in ~SwFrm superclass dtor

...as done in SwAnchoredObject::FindAnchorCharFrm
(sw/source/core/layout/anchoredobject.cxx) during CppunitTest_sw_ooxmlexport5:

SwAnchoredObject::FindAnchorCharFrm
SwAnchoredObject::GetAnchorFrmContainingAnchPos
SwAnchoredObject::FindPageFrmOfAnchor
lcl_NotifyBackgroundOfObj
SwDrawContact::DisconnectFromLayout
SwDrawContact::DisconnectObjFromLayout
SwFrm::Destroy
SwFrm::~SwFrm
SwCntntFrm::~SwCntntFrm
SwTxtFrm::~SwTxtFrm
SwTxtFrm::~SwTxtFrm
SwLayoutFrm::Destroy
SwLayoutFrm::~SwLayoutFrm
SwCellFrm::~SwCellFrm
SwCellFrm::~SwCellFrm
SwLayoutFrm::Destroy
SwLayoutFrm::~SwLayoutFrm
SwRowFrm::~SwRowFrm
SwRowFrm::~SwRowFrm
SwLayoutFrm::Destroy
SwLayoutFrm::~SwLayoutFrm
SwTabFrm::~SwTabFrm
SwTabFrm::~SwTabFrm
SwFlyFrm::DeleteCnt
SwFlyFrm::~SwFlyFrm
SwFlyFreeFrm::~SwFlyFreeFrm
SwFlyAtCntFrm::~SwFlyAtCntFrm
SwFlyAtCntFrm::~SwFlyAtCntFrm
SwLayoutFrm::Destroy
SwLayoutFrm::~SwLayoutFrm
SwBodyFrm::~SwBodyFrm
SwBodyFrm::~SwBodyFrm
SwLayoutFrm::Destroy
SwLayoutFrm::~SwLayoutFrm
SwFtnBossFrm::~SwFtnBossFrm
SwPageFrm::~SwPageFrm
SwPageFrm::~SwPageFrm
SwLayoutFrm::Destroy
SwRootFrm::~SwRootFrm
SwRootFrm::~SwRootFrm
boost::checked_delete<SwRootFrm>
boost::detail::sp_counted_impl_p<SwRootFrm>::dispose
boost::detail::sp_counted_base::release
boost::detail::shared_count::~shared_count
boost::shared_ptr<SwRootFrm>::~shared_ptr
SwViewShell::~SwViewShell
SwCrsrShell::~SwCrsrShell
SwEditShell::~SwEditShell
SwFEShell::~SwFEShell
SwWrtShell::~SwWrtShell
SwWrtShell::~SwWrtShell
SwView::~SwView
SwView::~SwView
SfxViewFrame::ReleaseObjectShell_Impl
SfxViewFrame::~SfxViewFrame
SfxViewFrame::~SfxViewFrame
SfxViewFrame::Close
SfxFrame::DoClose_Impl
SfxBaseController::dispose
(anonymous namespace)::Frame::setComponent
(anonymous namespace)::Frame::close
SfxFrame::DoClose
SfxViewFrame::Notify
SfxBroadcaster::Broadcast
SfxModelListener_Impl::notifyClosing
SfxBaseModel::close
SwXTextDocument::close
SfxBaseModel::dispose
SwXTextDocument::dispose
SwModelTestBase::tearDown
...

Change-Id: I4c00fa8eebf0346a2bad81a9e362cd901555bbf0

sw/source/core/draw/dcontact.cxx

@@ -1597,7 +1597,7 @@ void SwDrawContact::DisconnectFromLayout( bool _bMoveMasterToInvisibleLayer )
     // --> #i36181# - notify background of drawing object
     if ( _bMoveMasterToInvisibleLayer &&
          !(GetFmt()->GetDoc()->IsInDtor()) &&
-         GetAnchorFrm() )
+         GetAnchorFrm() && !GetAnchorFrm()->IsInDtor() )
     {
         const Rectangle aOldRect( maAnchoredDrawObj.GetObjRectWithSpaces().SVRect() );
         lcl_NotifyBackgroundOfObj( *this, *GetMaster(), &aOldRect );

sw/source/core/inc/frame.hxx

@@ -260,6 +260,7 @@ class SwFrm: public SwClient, public SfxBroadcaster
     static SwCache *mpCache;
 
     bool mbIfAccTableShouldDisposing;
+    bool mbInDtor;
 
     // #i65250#
     // frame ID is now in general available - used for layout loop control
@@ -846,6 +847,8 @@ public:
 
     virtual ~SwFrm();
 
+    bool IsInDtor() const { return mbInDtor; }
+
     // No inline cause we need the function pointers
     long GetTopMargin() const;
     long GetBottomMargin() const;

sw/source/core/layout/ssfrm.cxx

@@ -338,6 +338,8 @@ Point SwFrm::GetFrmAnchorPos( bool bIgnoreFlysAnchoredAtThisFrame ) const
 
 void SwFrm::Destroy()
 {
+    mbInDtor = true;
+
     // accessible objects for fly and cell frames have been already disposed
     // by the destructors of the derived classes.
     if( IsAccessibleFrm() && !(IsFlyFrm() || IsCellFrm()) && GetDep() )

sw/source/core/layout/wsfrm.cxx

@@ -71,6 +71,7 @@ using namespace ::com::sun::star;
 SwFrm::SwFrm( SwModify *pMod, SwFrm* pSib ) :
     SwClient( pMod ),
     mbIfAccTableShouldDisposing( false ), //A member to identify if the acc table should dispose
+    mbInDtor(false),
     mnFrmId( SwFrm::mnLastFrmId++ ),
     mpRoot( pSib ? pSib->getRootFrm() : 0 ),
     mpUpper( 0 ),