tdf#118893: avoid nullptr dereference

Change-Id: I56ada18348ed1b1ebe5e1d6f000391965d822b4a
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/89815
Tested-by: Jenkins
Reviewed-by: Mike Kaganski <mike.kaganski@collabora.com>
diff --git a/sd/source/ui/app/sdxfer.cxx b/sd/source/ui/app/sdxfer.cxx
index fea7638..f480680 100644
--- a/sd/source/ui/app/sdxfer.cxx
+++ b/sd/source/ui/app/sdxfer.cxx
@@ -243,7 +243,7 @@ void SdTransferable::CreateData()

        SdPage* pPage = mpSdDrawDocument->GetSdPage(0, PageKind::Standard);

        if( 1 == pPage->GetObjCount() )
        if( pPage && 1 == pPage->GetObjCount() )
            CreateObjectReplacement( pPage->GetObj( 0 ) );

        mpVDev = VclPtr<VirtualDevice>::Create( *Application::GetDefaultDevice() );