valgrind: SfxBaseModel's pImpl of fallback TargetDocument for paste leaks

e.g. repeatedly pasting a metafile into writer and deleting it.

==13369== 342 (232 direct, 110 indirect) bytes in 1 blocks are definitely lost in loss record 19,396 of 22,170
==13369==    at 0x4A06965: operator new(unsigned long) (in /usr/lib64/valgrind/vgpreload_memcheck-amd64-linux.so)
==13369==    by 0x686D72E: SfxBaseModel::SfxBaseModel(SfxObjectShell*) (sfxbasemodel.cxx:518)
==13369==    by 0x288CA9C1: SvxUnoDrawingModel::SvxUnoDrawingModel(SdrModel*) (unomod.cxx:255)
==13369==    by 0x28961055: SvxDrawingLayerImport(SdrModel*, com::sun::star::uno::Reference<com::sun::star::io::XInputStream> const&, com::sun::star::uno::Reference<com::sun::star::lang::XComponent> const&, char const*) (xmlexport.cxx:164)
==13369==    by 0x28960FA2: SvxDrawingLayerImport(SdrModel*, com::sun::star::uno::Reference<com::sun::star::io::XInputStream> const&, com::sun::star::uno::Reference<com::sun::star::lang::XComponent> const&) (xmlexport.cxx:148)
==13369==    by 0x2896175E: SvxDrawingLayerImport(SdrModel*, com::sun::star::uno::Reference<com::sun::star::io::XInputStream> const&) (xmlexport.cxx:254)
==13369==    by 0x240B1002: SwFEShell::Paste(SvStream&, unsigned short, Point const*) (fecopy.cxx:1333)
==13369==    by 0x247B981A: SwTransferable::_PasteSdrFormat(TransferableDataHelper&, SwWrtShell&, unsigned short, Point const*, unsigned char, bool) (swdtflvr.cxx:2207)
==13369==    by 0x247B678E: SwTransferable::PasteData(TransferableDataHelper&, SwWrtShell&, unsigned short, unsigned long, unsigned short, bool, bool, Point const*, signed char, bool) (swdtflvr.cxx:1481)
==13369==    by 0x247B5AE4: SwTransferable::Paste(SwWrtShell&, TransferableDataHelper&) (swdtflvr.cxx:1150)
==13369==    by 0x2488FCCE: SwBaseShell::ExecClpbrd(SfxRequest&) (basesh.cxx:277)

     Reference< lang::XComponent > xTargetDocument( xComponent );
     if( !xTargetDocument.is() )
     {
>        xTargetDocument = new SvxUnoDrawingModel( pModel );
         pModel->setUnoModel( Reference< XInterface >::query( xTargetDocument ) );
     }

Change-Id: I3bd0fc983d9b6bdcdc91071a4ec3d2c584397ebf

sfx2/source/doc/sfxbasemodel.cxx

@@ -523,18 +523,15 @@ SfxBaseModel::SfxBaseModel( SfxObjectShell *pObjectShell )
     }
 }
 
-
 //  destructor
-
-
 SfxBaseModel::~SfxBaseModel()
 {
+    //In SvxDrawingLayerImport when !xTargetDocument the fallback SvxUnoDrawingModel created there
+    //never gets disposed called on it, so m_pData leaks.
+    delete m_pData, m_pData = 0;
 }
 
-
 //  XInterface
-
-
 Any SAL_CALL SfxBaseModel::queryInterface( const uno::Type& rType ) throw( RuntimeException, std::exception )
 {
     if  (   ( !m_bSupportEmbeddedScripts && rType.equals( cppu::UnoType<document::XEmbeddedScripts>::get() ) )
@@ -545,10 +542,7 @@ Any SAL_CALL SfxBaseModel::queryInterface( const uno::Type& rType ) throw( Runti
     return SfxBaseModel_Base::queryInterface( rType );
 }
 
-
 //  XInterface
-
-
 void SAL_CALL SfxBaseModel::acquire() throw( )
 {
     // Attention: