kde#52609 RTF import: fix memory leak

This is similar to f7ef8464 (abi#2128
RTF import: fix memory leak, 2013-11-28).

Change-Id: Id57320466e6fb302ec8616ccc9f4f9429b8eff21

sw/qa/core/data/rtf/pass/kde52609.rtf

+{\rtf1
+{\headerl
+}
+{\footerl
+}
+first line\par
+second line\par
+}

writerfilter/source/rtftok/rtfdocumentimpl.cxx

@@ -4892,6 +4892,22 @@ int RTFDocumentImpl::popState()
     RTFParserState aState(m_aStates.top());
     m_bWasInFrame = aState.aFrame.inFrame();
 
+    // dmapper expects some content in header/footer, so if there would be nothing, add an empty paragraph.
+    if (m_pTokenizer->getGroup() == 1 && m_bFirstRun)
+    {
+        switch (m_nStreamType)
+        {
+        case NS_ooxml::LN_headerl:
+        case NS_ooxml::LN_headerr:
+        case NS_ooxml::LN_headerf:
+        case NS_ooxml::LN_footerl:
+        case NS_ooxml::LN_footerr:
+        case NS_ooxml::LN_footerf:
+            dispatchSymbol(RTF_PAR);
+            break;
+        }
+    }
+
     switch (aState.nDestinationState)
     {
     case DESTINATION_FONTTABLE: