ofz: leak of prefixes in skipped elements

Change-Id: I8e83eb605bdf5991988e147cf8478e44c858a2b0
Reviewed-on: https://gerrit.libreoffice.org/42320Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>

xmlscript/source/xml_helper/xml_impctx.cxx

@@ -545,6 +545,11 @@ void DocumentHandlerImpl::startElement(
     else
     {
         ++m_nSkipElements;
+
+        // pop prefixes
+        for (sal_Int32 nPos = elementEntry->m_prefixes.size(); nPos--;)
+            popPrefix(elementEntry->m_prefixes[nPos]);
+
         SAL_INFO("xmlscript.xmlhelper", " no context given on createChildElement() => ignoring element \"" << rQElementName << "\" ...");
     }
     }