sw: accept a const text node in SwRDFHelper::getTextNodeStatements()

It's an implementation detail that the used UNO API needs a non-cost
text node, even if only read methods are called on the wrapper object.

Change-Id: If15eaca48339f1531fd54da3422a6b7c41eb48f7

sw/inc/rdfhelper.hxx

@@ -23,7 +23,7 @@ class SW_DLLPUBLIC SwRDFHelper
 {
 public:
     /// Gets all (rTextNode, key, value) statements in RDF graphs of type rType.
-    static std::map<OUString, OUString> getTextNodeStatements(const OUString& rType, SwTextNode& rTextNode);
+    static std::map<OUString, OUString> getTextNodeStatements(const OUString& rType, const SwTextNode& rTextNode);
     /// Add an (rTextNode, key, value) statement in the graph of type rType -- or if it does not exist, create a graph at rPath first.
     static void addTextNodeStatement(const OUString& rType, const OUString& rPath, SwTextNode& rTextNode, const OUString& rKey, const OUString& rValue);
 };

sw/source/core/doc/rdfhelper.cxx

@@ -22,10 +22,13 @@
 
 using namespace com::sun::star;
 
-std::map<OUString, OUString> SwRDFHelper::getTextNodeStatements(const OUString& rType, SwTextNode& rTextNode)
+std::map<OUString, OUString> SwRDFHelper::getTextNodeStatements(const OUString& rType, const SwTextNode& rNode)
 {
     std::map<OUString, OUString> aRet;
 
+    // We only read the node, but CreateXParagraph() needs a non-cost one.
+    SwTextNode& rTextNode = const_cast<SwTextNode&>(rNode);
+
     uno::Reference<uno::XComponentContext> xComponentContext(comphelper::getProcessComponentContext());
     uno::Reference<rdf::XURI> xType = rdf::URI::create(xComponentContext, rType);
     uno::Reference<rdf::XDocumentMetadataAccess> xDocumentMetadataAccess(rTextNode.GetDoc()->GetDocShell()->GetBaseModel(), uno::UNO_QUERY);