ofz#10696 null-deref

since...

commit c6b8587eef
Date:   Wed Sep 19 16:35:10 2018 +0200

    loplugin:useuniqueptr in SvxRTFParser

Change-Id: Id901d5645500fedcb54b11e1b5b27fe81281f5a2
Reviewed-on: https://gerrit.libreoffice.org/61033
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>
Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>

editeng/source/rtf/svxrtf.cxx

@@ -680,6 +680,7 @@ void SvxRTFParser::AttrGroupEnd()   // process the current, delete from Stack
     if( !aAttrStack.empty() )
     {
         std::unique_ptr<SvxRTFItemStackType> pOld = std::move(aAttrStack.back());
+        aAttrStack.pop_back();
         SvxRTFItemStackType *pCurrent = aAttrStack.empty() ? nullptr : aAttrStack.back().get();
 
         do {        // middle check loop