Add XML dumping of the new 'SwTableCellRedline'

Change-Id: I4072130ff0ce712f02d1dd8f12003170116216a2
Reviewed-on: https://gerrit.libreoffice.org/7876Reviewed-by: Miklos Vajna <vmiklos@collabora.co.uk>
Tested-by: Miklos Vajna <vmiklos@collabora.co.uk>

sw/source/core/docnode/nodedump.cxx

@@ -618,8 +618,11 @@ void SwExtraRedlineTbl::dumpAsXml( xmlTextWriterPtr w )
         writer.startElement( "swextraredline" );
         {
             const SwTableRowRedline*           pTableRowRedline           = dynamic_cast<const SwTableRowRedline*>(pExtraRedline);
+            const SwTableCellRedline*          pTableCellRedline          = dynamic_cast<const SwTableCellRedline*>(pExtraRedline);
             if (pTableRowRedline)
                 writer.writeFormatAttribute( "extra_redline_type", "%s", BAD_CAST( "table row" ) );
+            else if (pTableCellRedline)
+                writer.writeFormatAttribute( "extra_redline_type", "%s", BAD_CAST( "table cell" ) );
             else
                 writer.writeFormatAttribute( "extra_redline_type", "%s", BAD_CAST( "UNKNOWN" ) );
         }