Adding upstream version 1.2.2.upstream/1.2.2upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1233 insertions, 0 deletions

diff --git a/src/rdf.cpp b/src/rdf.cpp
new file mode 100644
index 0000000..3aeb0af
--- /dev/null
+++ b/src/rdf.cpp
@@ -0,0 +1,1233 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/** @file
+ * RDF manipulation functions.
+ *
+ * @todo move these to xml/ instead of dialogs/
+ */
+/* Authors:
+ *   Kees Cook <kees@outflux.net>
+ *   Jon Phillips <jon@rejon.org>
+ *   Jon A. Cruz <jon@joncruz.org>
+ *
+ * Copyright (C) 2004 Kees Cook <kees@outflux.net>
+ * Copyright (C) 2006 Jon Phillips <jon@rejon.org>
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#include "inkscape.h"
+#include "preferences.h"
+#include "rdf.h"
+
+#include "object/sp-item-group.h"
+#include "object/sp-root.h"
+
+#include "xml/repr.h"
+
+/*
+   Example RDF XML from various places...
+
+<rdf:RDF xmlns="http://creativecommons.org/ns#"
+    xmlns:dc="http://purl.org/dc/elements/1.1/"
+    xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#">
+<Work rdf:about="">
+   <dc:title>title of work</dc:title>
+   <dc:date>year</dc:date>
+   <dc:description>description of work</dc:description>
+   <dc:creator><Agent>
+      <dc:title>creator</dc:title>
+   </Agent></dc:creator>
+   <dc:rights><Agent>
+      <dc:title>holder</dc:title>
+   </Agent></dc:rights>
+   <dc:type rdf:resource="http://purl.org/dc/dcmitype/StillImage" />
+   <dc:source rdf:resource="source"/>
+   <license rdf:resource="http://creativecommons.org/licenses/by/4.0/"
+/>
+</Work>
+
+
+  <rdf:RDF xmlns="http://creativecommons.org/ns#"
+      xmlns:dc="http://purl.org/dc/elements/1.1/"
+      xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#">
+  <Work rdf:about="">
+     <dc:title>SVG Road Signs</dc:title>
+     <dc:rights><Agent>
+        <dc:title>John Cliff</dc:title>
+     </Agent></dc:rights>
+     <dc:type rdf:resource="http://purl.org/dc/dcmitype/StillImage" />
+     <license rdf:resource="http://creativecommons.org/ns#PublicDomain" />
+  </Work>
+
+  <License rdf:about="http://creativecommons.org/ns#PublicDomain">
+     <permits rdf:resource="http://creativecommons.org/ns#Reproduction" />
+     <permits rdf:resource="http://creativecommons.org/ns#Distribution" />
+     <permits rdf:resource="http://creativecommons.org/ns#DerivativeWorks" />
+  </License>
+
+</rdf:RDF>
+
+
+Bag example:
+
+<dc:subject>
+<rdf:Bag>
+<rdf:li>open clip art logo</rdf:li>
+<rdf:li>images</rdf:li>
+<rdf:li>logo</rdf:li>
+<rdf:li>clip art</rdf:li>
+<rdf:li>ocal</rdf:li>
+<rdf:li>logotype</rdf:li>
+<rdf:li>filetype</rdf:li>
+</rdf:Bag>
+</dc:subject>
+*/
+
+// clang-format off
+struct rdf_double_t rdf_license_empty [] = {
+    { nullptr, nullptr }
+};
+
+struct rdf_double_t rdf_license_cc_a [] = {
+    { "cc:permits", "http://creativecommons.org/ns#Reproduction", },
+    { "cc:permits", "http://creativecommons.org/ns#Distribution", },
+    { "cc:requires", "http://creativecommons.org/ns#Notice", },
+    { "cc:requires", "http://creativecommons.org/ns#Attribution", },
+    { "cc:permits", "http://creativecommons.org/ns#DerivativeWorks", },
+    { nullptr, nullptr }
+};
+
+struct rdf_double_t rdf_license_cc_a_sa [] = {
+    { "cc:permits", "http://creativecommons.org/ns#Reproduction", },
+    { "cc:permits", "http://creativecommons.org/ns#Distribution", },
+    { "cc:requires", "http://creativecommons.org/ns#Notice", },
+    { "cc:requires", "http://creativecommons.org/ns#Attribution", },
+    { "cc:permits", "http://creativecommons.org/ns#DerivativeWorks", },
+    { "cc:requires", "http://creativecommons.org/ns#ShareAlike", },
+    { nullptr, nullptr }
+};
+
+struct rdf_double_t rdf_license_cc_a_nd [] = {
+    { "cc:permits", "http://creativecommons.org/ns#Reproduction", },
+    { "cc:permits", "http://creativecommons.org/ns#Distribution", },
+    { "cc:requires", "http://creativecommons.org/ns#Notice", },
+    { "cc:requires", "http://creativecommons.org/ns#Attribution", },
+    { nullptr, nullptr }
+};
+
+struct rdf_double_t rdf_license_cc_a_nc [] = {
+    { "cc:permits", "http://creativecommons.org/ns#Reproduction", },
+    { "cc:permits", "http://creativecommons.org/ns#Distribution", },
+    { "cc:requires", "http://creativecommons.org/ns#Notice", },
+    { "cc:requires", "http://creativecommons.org/ns#Attribution", },
+    { "cc:prohibits", "http://creativecommons.org/ns#CommercialUse", },
+    { "cc:permits", "http://creativecommons.org/ns#DerivativeWorks", },
+    { nullptr, nullptr }
+};
+
+struct rdf_double_t rdf_license_cc_a_nc_sa [] = {
+    { "cc:permits", "http://creativecommons.org/ns#Reproduction", },
+    { "cc:permits", "http://creativecommons.org/ns#Distribution", },
+    { "cc:requires", "http://creativecommons.org/ns#Notice", },
+    { "cc:requires", "http://creativecommons.org/ns#Attribution", },
+    { "cc:prohibits", "http://creativecommons.org/ns#CommercialUse", },
+    { "cc:permits", "http://creativecommons.org/ns#DerivativeWorks", },
+    { "cc:requires", "http://creativecommons.org/ns#ShareAlike", },
+    { nullptr, nullptr }
+};
+
+struct rdf_double_t rdf_license_cc_a_nc_nd [] = {
+    { "cc:permits", "http://creativecommons.org/ns#Reproduction", },
+    { "cc:permits", "http://creativecommons.org/ns#Distribution", },
+    { "cc:requires", "http://creativecommons.org/ns#Notice", },
+    { "cc:requires", "http://creativecommons.org/ns#Attribution", },
+    { "cc:prohibits", "http://creativecommons.org/ns#CommercialUse", },
+    { nullptr, nullptr }
+};
+
+struct rdf_double_t rdf_license_pd [] = {
+    { "cc:permits", "http://creativecommons.org/ns#Reproduction", },
+    { "cc:permits", "http://creativecommons.org/ns#Distribution", },
+    { "cc:permits", "http://creativecommons.org/ns#DerivativeWorks", },
+    { nullptr, nullptr }
+};
+
+struct rdf_double_t rdf_license_freeart [] = {
+    { "cc:permits", "http://creativecommons.org/ns#Reproduction", },
+    { "cc:permits", "http://creativecommons.org/ns#Distribution", },
+    { "cc:permits", "http://creativecommons.org/ns#DerivativeWorks", },
+    { "cc:requires", "http://creativecommons.org/ns#ShareAlike", },
+    { "cc:requires", "http://creativecommons.org/ns#Notice", },
+    { "cc:requires", "http://creativecommons.org/ns#Attribution", },
+    { nullptr, nullptr }
+};
+
+struct rdf_double_t rdf_license_ofl [] = {
+    { "cc:permits", "http://scripts.sil.org/pub/OFL/Reproduction", },
+    { "cc:permits", "http://scripts.sil.org/pub/OFL/Distribution", },
+    { "cc:permits", "http://scripts.sil.org/pub/OFL/Embedding", },
+    { "cc:permits", "http://scripts.sil.org/pub/OFL/DerivativeWorks", },
+    { "cc:requires", "http://scripts.sil.org/pub/OFL/Notice", },
+    { "cc:requires", "http://scripts.sil.org/pub/OFL/Attribution", },
+    { "cc:requires", "http://scripts.sil.org/pub/OFL/ShareAlike", },
+    { "cc:requires", "http://scripts.sil.org/pub/OFL/DerivativeRenaming", },
+    { "cc:requires", "http://scripts.sil.org/pub/OFL/BundlingWhenSelling", },
+    { nullptr, nullptr }
+};
+
+struct rdf_license_t rdf_licenses [] = {
+    { N_("CC Attribution"),
+      "http://creativecommons.org/licenses/by/4.0/",
+      rdf_license_cc_a,
+    },
+
+    { N_("CC Attribution-ShareAlike"),
+      "http://creativecommons.org/licenses/by-sa/4.0/",
+      rdf_license_cc_a_sa,
+    },
+
+    { N_("CC Attribution-NoDerivs"),
+      "http://creativecommons.org/licenses/by-nd/4.0/",
+      rdf_license_cc_a_nd,
+    },
+
+    { N_("CC Attribution-NonCommercial"),
+      "http://creativecommons.org/licenses/by-nc/4.0/",
+      rdf_license_cc_a_nc,
+    },
+
+    { N_("CC Attribution-NonCommercial-ShareAlike"),
+      "http://creativecommons.org/licenses/by-nc-sa/4.0/",
+      rdf_license_cc_a_nc_sa,
+    },
+
+    { N_("CC Attribution-NonCommercial-NoDerivs"),
+      "http://creativecommons.org/licenses/by-nc-nd/4.0/",
+      rdf_license_cc_a_nc_nd,
+    },
+
+    { N_("CC0 Public Domain Dedication"),
+      "http://creativecommons.org/publicdomain/zero/1.0/",
+      rdf_license_pd,
+    },
+
+    { N_("FreeArt"),
+      "http://artlibre.org/licence/lal",
+      rdf_license_freeart,
+    },
+
+    { N_("Open Font License"),
+      "http://scripts.sil.org/OFL",
+      rdf_license_ofl,
+    },
+
+    { nullptr, nullptr, rdf_license_empty, }
+};
+// clang-format on
+
+#define XML_TAG_NAME_SVG      "svg:svg"
+#define XML_TAG_NAME_METADATA "svg:metadata"
+#define XML_TAG_NAME_RDF      "rdf:RDF"
+#define XML_TAG_NAME_WORK     "cc:Work"
+#define XML_TAG_NAME_LICENSE  "cc:License"
+// Note the lowercase L!
+#define XML_TAG_NAME_LICENSE_PROP  "cc:license"
+
+
+// Remember when using the "title" and "tip" elements to pass them through
+// the localization functions when you use them!
+struct rdf_work_entity_t rdf_work_entities [] = {
+    // clang-format off
+    { "title", N_("Title:"), "dc:title", RDF_CONTENT,
+      N_("A name given to the resource"), RDF_FORMAT_LINE, RDF_EDIT_GENERIC,
+    },
+    { "date", N_("Date:"), "dc:date", RDF_CONTENT,
+      N_("A point or period of time associated with an event in the lifecycle of the resource"), RDF_FORMAT_LINE, RDF_EDIT_GENERIC,
+    },
+    { "format", N_("Format:"), "dc:format", RDF_CONTENT,
+      N_("The file format, physical medium, or dimensions of the resource"), RDF_FORMAT_LINE, RDF_EDIT_HARDCODED,
+    },
+    { "type", N_("Type:"), "dc:type", RDF_RESOURCE,
+      N_("The nature or genre of the resource"), RDF_FORMAT_LINE, RDF_EDIT_HARDCODED,
+    },
+
+    { "creator", N_("Creator:"), "dc:creator", RDF_AGENT,
+      N_("An entity primarily responsible for making the resource"), RDF_FORMAT_LINE, RDF_EDIT_GENERIC,
+    },
+    { "rights", N_("Rights:"), "dc:rights", RDF_AGENT,
+      N_("Information about rights held in and over the resource"), RDF_FORMAT_LINE, RDF_EDIT_GENERIC,
+    },
+    { "publisher", N_("Publisher:"), "dc:publisher", RDF_AGENT,
+      N_("An entity responsible for making the resource available"), RDF_FORMAT_LINE, RDF_EDIT_GENERIC,
+    },
+
+    { "identifier", N_("Identifier:"), "dc:identifier", RDF_CONTENT,
+      N_("An unambiguous reference to the resource within a given context"), RDF_FORMAT_LINE, RDF_EDIT_GENERIC,
+    },
+    { "source", N_("Source:"), "dc:source", RDF_CONTENT,
+      N_("A related resource from which the described resource is derived"), RDF_FORMAT_LINE, RDF_EDIT_GENERIC,
+    },
+    { "relation", N_("Relation:"), "dc:relation", RDF_CONTENT,
+      N_("A related resource"), RDF_FORMAT_LINE, RDF_EDIT_GENERIC,
+    },
+    { "language", N_("Language:"), "dc:language", RDF_CONTENT,
+      N_("A language of the resource"), RDF_FORMAT_LINE, RDF_EDIT_GENERIC,
+    },
+    { "subject", N_("Keywords:"), "dc:subject", RDF_BAG,
+      N_("The topic of the resource"), RDF_FORMAT_LINE, RDF_EDIT_GENERIC,
+    },
+    // TRANSLATORS: "Coverage": the spatial or temporal characteristics of the content.
+    // For info, see Appendix D of http://www.w3.org/TR/1998/WD-rdf-schema-19980409/
+    { "coverage", N_("Coverage:"), "dc:coverage", RDF_CONTENT,
+      N_("The spatial or temporal topic of the resource, the spatial applicability of the resource, or the jurisdiction under which the resource is relevant"), RDF_FORMAT_LINE, RDF_EDIT_GENERIC,
+    },
+
+    { "description", N_("Description:"), "dc:description", RDF_CONTENT,
+      N_("An account of the resource"), RDF_FORMAT_MULTILINE, RDF_EDIT_GENERIC,
+    },
+
+    // FIXME: need to handle 1 agent per line of input
+    { "contributor", N_("Contributors:"), "dc:contributor", RDF_AGENT,
+      N_("An entity responsible for making contributions to the resource"), RDF_FORMAT_MULTILINE, RDF_EDIT_GENERIC,
+    },
+
+    // TRANSLATORS: URL to a page that defines the license for the document
+    { "license_uri", N_("URI:"), "cc:license", RDF_RESOURCE,
+      // TRANSLATORS: this is where you put a URL to a page that defines the license
+      N_("URI to this document's license's namespace definition"), RDF_FORMAT_LINE, RDF_EDIT_SPECIAL,
+    },
+
+      // TRANSLATORS: fragment of XML representing the license of the document
+    { "license_fragment", N_("Fragment:"), "License", RDF_XML,
+      N_("XML fragment for the RDF 'License' section"), RDF_FORMAT_MULTILINE, RDF_EDIT_SPECIAL,
+    },
+
+    { nullptr, nullptr, nullptr, RDF_CONTENT,
+      nullptr, RDF_FORMAT_LINE, RDF_EDIT_HARDCODED,
+    }
+    // clang-format on
+};
+
+
+// Simple start of C++-ification:
+class RDFImpl
+{
+public:
+    /**
+     * Some implementations do not put RDF stuff inside <metadata>,
+     * so we need to check for it and add it if we don't see it.
+     */
+    static void ensureParentIsMetadata( SPDocument *doc, Inkscape::XML::Node *node );
+
+    static Inkscape::XML::Node const *getRdfRootRepr( SPDocument const * doc );
+    static Inkscape::XML::Node *ensureRdfRootRepr( SPDocument * doc );
+
+    static Inkscape::XML::Node const *getXmlRepr( SPDocument const * doc, gchar const * name );
+    static Inkscape::XML::Node *getXmlRepr( SPDocument * doc, gchar const * name );
+    static Inkscape::XML::Node *ensureXmlRepr( SPDocument * doc, gchar const * name );
+
+    static Inkscape::XML::Node const *getWorkRepr( SPDocument const * doc, gchar const * name );
+    static Inkscape::XML::Node *ensureWorkRepr( SPDocument * doc, gchar const * name );
+
+    static const gchar *getWorkEntity(SPDocument const * doc, struct rdf_work_entity_t & entity);
+    static unsigned int setWorkEntity(SPDocument * doc, struct rdf_work_entity_t & entity, gchar const * text);
+
+    static void setDefaults( SPDocument * doc );
+
+    /**
+     *  Pull the text out of an RDF entity, depends on how it's stored.
+     *
+     *  @return  A pointer to the entity's static contents as a string
+     *  @param   repr    The XML element to extract from
+     *  @param   entity  The desired RDF/Work entity
+     *
+     */
+    static const gchar *getReprText( Inkscape::XML::Node const * repr, struct rdf_work_entity_t const & entity );
+
+    static unsigned int setReprText( Inkscape::XML::Node * repr,
+                                     struct rdf_work_entity_t const & entity,
+                                     gchar const * text );
+
+    static struct rdf_license_t *getLicense(SPDocument *document);
+
+    static void setLicense(SPDocument * doc, struct rdf_license_t const * license);
+};
+
+/**
+ *  Retrieves a known RDF/Work entity by name.
+ *
+ *  @return  A pointer to an RDF/Work entity
+ *  @param   name  The desired RDF/Work entity
+ *
+ */
+struct rdf_work_entity_t *rdf_find_entity(gchar const * name)
+{
+    struct rdf_work_entity_t *entity;
+    for (entity=rdf_work_entities; entity->name; entity++) {
+        if (strcmp(entity->name,name)==0) break;
+    }
+    if (entity->name) return entity;
+    return nullptr;
+}
+
+/*
+ * Takes the inkscape rdf struct and spits out a static RDF, which is only
+ * useful for testing.  We must merge the rdf struct into the XML DOM for
+ * changes to be saved.
+ */
+/*
+
+   Since g_markup_printf_escaped doesn't exist for most people's glib
+   right now, this function will remain commented out since it's only
+   for generic debug anyway.  --Kees
+
+gchar *
+rdf_string(struct rdf_t * rdf)
+{
+    gulong overall=0;
+    gchar *string=NULL;
+
+    gchar *rdf_head="\
+<rdf:RDF xmlns=\"http://creativecommons.org/ns#\"\
+    xmlns:dc=\"http://purl.org/dc/elements/1.1/\"\
+    xmlns:rdf=\"http://www.w3.org/1999/02/22-rdf-syntax-ns#\">\
+";
+    gchar *work_head="\
+<Work rdf:about=\"\">\
+   <dc:type rdf:resource=\"http://purl.org/dc/dcmitype/StillImage\" />\
+";
+    gchar *work_title=NULL;
+    gchar *work_date=NULL;
+    gchar *work_description=NULL;
+    gchar *work_creator=NULL;
+    gchar *work_owner=NULL;
+    gchar *work_source=NULL;
+    gchar *work_license=NULL;
+    gchar *license_head=NULL;
+    gchar *license=NULL;
+    gchar *license_end="</License>\n";
+    gchar *work_end="</Work>\n";
+    gchar *rdf_end="</rdf:RDF>\n";
+
+    if (rdf && rdf->work_title && rdf->work_title[0]) {
+        work_title=g_markup_printf_escaped("   <dc:title>%s</dc:title>\n",
+            rdf->work_title);
+    overall+=strlen(work_title);
+    }
+    if (rdf && rdf->work_date && rdf->work_date[0]) {
+        work_date=g_markup_printf_escaped("   <dc:date>%s</dc:date>\n",
+            rdf->work_date);
+    overall+=strlen(work_date);
+    }
+    if (rdf && rdf->work_description && rdf->work_description[0]) {
+        work_description=g_markup_printf_escaped("   <dc:description>%s</dc:description>\n",
+            rdf->work_description);
+    overall+=strlen(work_description);
+    }
+    if (rdf && rdf->work_creator && rdf->work_creator[0]) {
+        work_creator=g_markup_printf_escaped("   <dc:creator><Agent>\
+      <dc:title>%s</dc:title>\
+   </Agent></dc:creator>\n",
+            rdf->work_creator);
+    overall+=strlen(work_creator);
+    }
+    if (rdf && rdf->work_owner && rdf->work_owner[0]) {
+        work_owner=g_markup_printf_escaped("   <dc:rights><Agent>\
+      <dc:title>%s</dc:title>\
+   </Agent></dc:rights>\n",
+            rdf->work_owner);
+    overall+=strlen(work_owner);
+    }
+    if (rdf && rdf->work_source && rdf->work_source[0]) {
+        work_source=g_markup_printf_escaped("   <dc:source rdf:resource=\"%s\" />\n",
+            rdf->work_source);
+    overall+=strlen(work_source);
+    }
+    if (rdf && rdf->license && rdf->license->work_rdf && rdf->license->work_rdf[0]) {
+        work_license=g_markup_printf_escaped("   <license rdf:resource=\"%s\" />\n",
+            rdf->license->work_rdf);
+    overall+=strlen(work_license);
+
+    license_head=g_markup_printf_escaped("<License rdf:about=\"%s\">\n",
+            rdf->license->work_rdf);
+    overall+=strlen(license_head);
+    overall+=strlen(rdf->license->license_rdf);
+    overall+=strlen(license_end);
+    }
+
+    overall+=strlen(rdf_head)+strlen(rdf_end);
+    overall+=strlen(work_head)+strlen(work_end);
+
+    overall++; // NULL term
+
+    if (!(string=(gchar*)g_malloc(overall))) {
+        return NULL;
+    }
+
+    string[0]='\0';
+    strcat(string,rdf_head);
+    strcat(string,work_head);
+
+    if (work_title)       strcat(string,work_title);
+    if (work_date)        strcat(string,work_date);
+    if (work_description) strcat(string,work_description);
+    if (work_creator)     strcat(string,work_creator);
+    if (work_owner)       strcat(string,work_owner);
+    if (work_source)      strcat(string,work_source);
+    if (work_license)     strcat(string,work_license);
+
+    strcat(string,work_end);
+    if (license_head) {
+        strcat(string,license_head);
+    strcat(string,rdf->license->license_rdf);
+    strcat(string,license_end);
+    }
+    strcat(string,rdf_end);
+
+    return string;
+}
+*/
+
+
+const gchar *RDFImpl::getReprText( Inkscape::XML::Node const * repr, struct rdf_work_entity_t const & entity )
+{
+    g_return_val_if_fail (repr != nullptr, NULL);
+    static gchar * bag = nullptr;
+    gchar * holder = nullptr;
+
+    Inkscape::XML::Node const * temp = nullptr;
+    switch (entity.datatype) {
+        case RDF_CONTENT:
+            temp = repr->firstChild();
+            if ( temp == nullptr ) return nullptr;
+
+            return temp->content();
+
+        case RDF_AGENT:
+            temp = sp_repr_lookup_name ( repr, "cc:Agent", 1 );
+            if ( temp == nullptr ) return nullptr;
+
+            temp = sp_repr_lookup_name ( temp, "dc:title", 1 );
+            if ( temp == nullptr ) return nullptr;
+
+            temp = temp->firstChild();
+            if ( temp == nullptr ) return nullptr;
+
+            return temp->content();
+
+        case RDF_RESOURCE:
+            return repr->attribute("rdf:resource");
+
+        case RDF_XML:
+            return "xml goes here";
+
+        case RDF_BAG:
+            /* clear the static string.  yucky. */
+            if (bag) g_free(bag);
+            bag = nullptr;
+
+            temp = sp_repr_lookup_name ( repr, "rdf:Bag", 1 );
+            if ( temp == nullptr ) {
+                /* backwards compatible: read contents */
+                temp = repr->firstChild();
+                if ( temp == nullptr ) return nullptr;
+
+                return temp->content();
+            }
+
+            for ( temp = temp->firstChild() ;
+                  temp ;
+                  temp = temp->next() ) {
+                if (!strcmp(temp->name(),"rdf:li") &&
+                    temp->firstChild()) {
+                    const gchar * str = temp->firstChild()->content();
+                    if (bag) {
+                        holder = bag;
+                        bag = g_strconcat(holder, ", ", str, nullptr);
+                        g_free(holder);
+                    }
+                    else {
+                        bag = g_strdup(str);
+                    }
+                }
+            }
+            return bag;
+
+        default:
+            break;
+    }
+    return nullptr;
+}
+
+unsigned int RDFImpl::setReprText( Inkscape::XML::Node * repr,
+                                   struct rdf_work_entity_t const & entity,
+                                   gchar const * text )
+{
+    g_return_val_if_fail ( repr != nullptr, 0);
+    g_return_val_if_fail ( text != nullptr, 0);
+    gchar * str = nullptr;
+    gchar** strlist = nullptr;
+    int i;
+
+    Inkscape::XML::Node * temp=nullptr;
+    Inkscape::XML::Node * parent=repr;
+
+    Inkscape::XML::Document * xmldoc = parent->document();
+    g_return_val_if_fail (xmldoc != nullptr, FALSE);
+
+    // set document's title element to the RDF title
+    if (!strcmp(entity.name, "title")) {
+        SPDocument *doc = SP_ACTIVE_DOCUMENT;
+        if (doc && doc->getRoot()) {
+            doc->getRoot()->setTitle(text);
+        }
+    }
+
+    switch (entity.datatype) {
+        case RDF_CONTENT:
+            temp = parent->firstChild();
+            if ( temp == nullptr ) {
+                temp = xmldoc->createTextNode( text );
+                g_return_val_if_fail (temp != nullptr, FALSE);
+
+                parent->appendChild(temp);
+                Inkscape::GC::release(temp);
+
+                return TRUE;
+            }
+            else {
+                temp->setContent(text);
+                return TRUE;
+            }
+
+        case RDF_AGENT:
+            temp = sp_repr_lookup_name ( parent, "cc:Agent", 1 );
+            if ( temp == nullptr ) {
+                temp = xmldoc->createElement ( "cc:Agent" );
+                g_return_val_if_fail (temp != nullptr, FALSE);
+
+                parent->appendChild(temp);
+                Inkscape::GC::release(temp);
+            }
+            parent = temp;
+
+            temp = sp_repr_lookup_name ( parent, "dc:title", 1 );
+            if ( temp == nullptr ) {
+                temp = xmldoc->createElement ( "dc:title" );
+                g_return_val_if_fail (temp != nullptr, FALSE);
+
+                parent->appendChild(temp);
+                Inkscape::GC::release(temp);
+            }
+            parent = temp;
+
+            temp = parent->firstChild();
+            if ( temp == nullptr ) {
+                temp = xmldoc->createTextNode( text );
+                g_return_val_if_fail (temp != nullptr, FALSE);
+
+                parent->appendChild(temp);
+                Inkscape::GC::release(temp);
+
+                return TRUE;
+            }
+            else {
+                temp->setContent(text);
+				return TRUE;
+            }
+
+        case RDF_RESOURCE:
+            parent->setAttribute("rdf:resource", text );
+            return true;
+
+        case RDF_XML:
+            return 1;
+
+        case RDF_BAG:
+            /* find/create the rdf:Bag item */
+            temp = sp_repr_lookup_name ( parent, "rdf:Bag", 1 );
+            if ( temp == nullptr ) {
+                /* backward compatibility: drop the dc:subject contents */
+                while ( (temp = parent->firstChild()) ) {
+                    parent->removeChild(temp);
+                }
+
+                temp = xmldoc->createElement ( "rdf:Bag" );
+                g_return_val_if_fail (temp != nullptr, FALSE);
+
+                parent->appendChild(temp);
+                Inkscape::GC::release(temp);
+            }
+            parent = temp;
+
+            /* toss all the old list items */
+            while ( (temp = parent->firstChild()) ) {
+                parent->removeChild(temp);
+            }
+
+            /* chop our list up on commas */
+            strlist = g_strsplit( text, ",", 0);
+
+            for (i = 0; (str = strlist[i]); i++) {
+                temp = xmldoc->createElement ( "rdf:li" );
+                g_return_val_if_fail (temp != nullptr, 0);
+
+                parent->appendChild(temp);
+                Inkscape::GC::release(temp);
+
+                Inkscape::XML::Node * child = xmldoc->createTextNode( g_strstrip(str) );
+                g_return_val_if_fail (child != nullptr, 0);
+
+                temp->appendChild(child);
+                Inkscape::GC::release(child);
+            }
+            g_strfreev( strlist );
+
+            return 1;
+
+        default:
+            break;
+    }
+    return 0;
+}
+
+void RDFImpl::ensureParentIsMetadata( SPDocument *doc, Inkscape::XML::Node *node )
+{
+    if ( !node ) {
+        g_critical("Null node passed to ensureParentIsMetadata().");
+    } else if ( !node->parent() ) {
+        g_critical( "No parent node when verifying <metadata> placement." );
+    } else {
+        Inkscape::XML::Node * currentParent = node->parent();
+        if ( strcmp( currentParent->name(), XML_TAG_NAME_METADATA ) != 0 ) {
+            Inkscape::XML::Node * metadata = doc->getReprDoc()->createElement( XML_TAG_NAME_METADATA );
+            if ( !metadata ) {
+                g_critical("Unable to create metadata element.");
+            } else {
+                // attach the metadata node
+                currentParent->appendChild( metadata );
+                Inkscape::GC::release( metadata );
+
+                // move the node into it
+                Inkscape::GC::anchor( node );
+                sp_repr_unparent( node );
+                metadata->appendChild( node );
+                Inkscape::GC::release( node );
+            }
+        }
+    }
+}
+
+Inkscape::XML::Node const *RDFImpl::getRdfRootRepr( SPDocument const * doc )
+{
+    Inkscape::XML::Node const *rdf = nullptr;
+    if ( !doc ) {
+        g_critical("Null doc passed to getRdfRootRepr()");
+    } else if ( !doc->getReprDoc() ) {
+        g_critical("XML doc is null.");
+    } else {
+        rdf = sp_repr_lookup_name( doc->getReprDoc(), XML_TAG_NAME_RDF );
+    }
+
+    return rdf;
+}
+
+Inkscape::XML::Node *RDFImpl::ensureRdfRootRepr( SPDocument * doc )
+{
+    Inkscape::XML::Node *rdf = nullptr;
+    if ( !doc ) {
+        g_critical("Null doc passed to ensureRdfRootRepr()");
+    } else if ( !doc->getReprDoc() ) {
+        g_critical("XML doc is null.");
+    } else {
+        rdf = sp_repr_lookup_name( doc->getReprDoc(), XML_TAG_NAME_RDF );
+        if ( !rdf ) {
+            Inkscape::XML::Node * svg = sp_repr_lookup_name( doc->getReprRoot(), XML_TAG_NAME_SVG );
+            if ( !svg ) {
+                g_critical("Unable to locate svg element.");
+            } else {
+                Inkscape::XML::Node * parent = sp_repr_lookup_name( svg, XML_TAG_NAME_METADATA, 1);
+                if ( parent == nullptr ) {
+                    parent = doc->getReprDoc()->createElement( XML_TAG_NAME_METADATA );
+                    if ( !parent ) {
+                        g_critical("Unable to create metadata element");
+                    } else {
+                        svg->appendChild(parent);
+                        Inkscape::GC::release(parent);
+                    }
+                }
+
+                if ( parent && !parent->document() ) {
+                    g_critical("Parent has no document");
+                } else if ( parent ) {
+                    rdf = parent->document()->createElement( XML_TAG_NAME_RDF );
+                    if ( !rdf ) {
+                        g_critical("Unable to create root RDF element.");
+                    } else {
+                        parent->appendChild(rdf);
+                        Inkscape::GC::release(rdf);
+                    }
+                }
+            }
+        }
+    }
+
+    if ( rdf ) {
+        ensureParentIsMetadata( doc, rdf );
+    }
+
+    return rdf;
+}
+
+Inkscape::XML::Node const *RDFImpl::getXmlRepr( SPDocument const * doc, gchar const * name )
+{
+    Inkscape::XML::Node const * xml = nullptr;
+    if ( !doc ) {
+        g_critical("Null doc passed to getXmlRepr()");
+    } else if ( !doc->getReprDoc() ) {
+        g_critical("XML doc is null.");
+    } else if (!name) {
+        g_critical("Null name passed to getXmlRepr()");
+    } else {
+        Inkscape::XML::Node const * rdf = getRdfRootRepr( doc );
+        if ( rdf ) {
+            xml = sp_repr_lookup_name( rdf, name );
+        }
+    }
+    return xml;
+}
+
+Inkscape::XML::Node *RDFImpl::getXmlRepr( SPDocument * doc, gchar const * name )
+{
+    Inkscape::XML::Node const *xml = getXmlRepr( const_cast<SPDocument const *>(doc), name );
+
+    return const_cast<Inkscape::XML::Node *>(xml);
+}
+
+Inkscape::XML::Node *RDFImpl::ensureXmlRepr( SPDocument * doc, gchar const * name )
+{
+    Inkscape::XML::Node * xml = nullptr;
+    if ( !doc ) {
+        g_critical("Null doc passed to ensureXmlRepr()");
+    } else if ( !doc->getReprDoc() ) {
+        g_critical("XML doc is null.");
+    } else if (!name) {
+        g_critical("Null name passed to ensureXmlRepr()");
+    } else {
+        Inkscape::XML::Node * rdf = ensureRdfRootRepr( doc );
+        if ( rdf ) {
+            xml = sp_repr_lookup_name( rdf, name );
+            if ( !xml ) {
+                xml = doc->getReprDoc()->createElement( name );
+                if ( !xml ) {
+                    g_critical("Unable to create xml element <%s>.", name);
+                } else {
+                    xml->setAttribute("rdf:about", "" );
+
+                    rdf->appendChild(xml);
+                    Inkscape::GC::release(xml);
+                }
+            }
+        }
+    }
+    return xml;
+}
+
+Inkscape::XML::Node const *RDFImpl::getWorkRepr( SPDocument const * doc, gchar const * name )
+{
+    Inkscape::XML::Node const * item = nullptr;
+    if ( !doc ) {
+        g_critical("Null doc passed to getWorkRepr()");
+    } else if ( !doc->getReprDoc() ) {
+        g_critical("XML doc is null.");
+    } else if (!name) {
+        g_critical("Null name passed to getWorkRepr()");
+    } else {
+        Inkscape::XML::Node const* work = getXmlRepr( doc, XML_TAG_NAME_WORK );
+        if ( work ) {
+            item = sp_repr_lookup_name( work, name, 1 );
+        }
+    }
+    return item;
+}
+
+Inkscape::XML::Node *RDFImpl::ensureWorkRepr( SPDocument * doc, gchar const * name )
+{
+    Inkscape::XML::Node * item = nullptr;
+    if ( !doc ) {
+        g_critical("Null doc passed to ensureWorkRepr()");
+    } else if ( !doc->getReprDoc() ) {
+        g_critical("XML doc is null.");
+    } else if (!name) {
+        g_critical("Null name passed to ensureWorkRepr()");
+    } else {
+        Inkscape::XML::Node * work = ensureXmlRepr( doc, XML_TAG_NAME_WORK );
+        if ( work ) {
+            item = sp_repr_lookup_name( work, name, 1 );
+            if ( !item ) {
+                //printf("missing XML '%s'\n",name);
+                item = doc->getReprDoc()->createElement( name );
+                if ( !item ) {
+                    g_critical("Unable to create xml element <%s>", name);
+                } else {
+                    work->appendChild(item);
+                    Inkscape::GC::release(item);
+                }
+            }
+        }
+    }
+    return item;
+}
+
+
+// Public API:
+const gchar *rdf_get_work_entity(SPDocument const * doc, struct rdf_work_entity_t * entity)
+{
+    const gchar *result = nullptr;
+    if ( !doc ) {
+        g_critical("Null doc passed to rdf_get_work_entity()");
+    } else if ( entity ) {
+        //g_message("want '%s'\n",entity->title);
+
+        result = RDFImpl::getWorkEntity( doc, *entity );
+
+        //g_message("found '%s' == '%s'\n", entity->title, result );
+    }
+    return result;
+}
+
+const gchar *RDFImpl::getWorkEntity(SPDocument const * doc, struct rdf_work_entity_t & entity)
+{
+    gchar const *result = nullptr;
+
+    Inkscape::XML::Node const * item = getWorkRepr( doc, entity.tag );
+    if ( item ) {
+        result = getReprText( item, entity );
+        // TODO note that this is the location that used to set the title if needed. Ensure code it not required.
+    }
+
+    return result;
+}
+
+// Public API:
+unsigned int rdf_set_work_entity(SPDocument * doc, struct rdf_work_entity_t * entity,
+                                 const gchar * text)
+{
+    unsigned int result = 0;
+    if ( !doc ) {
+        g_critical("Null doc passed to rdf_set_work_entity()");
+    } else if ( entity ) {
+        result = RDFImpl::setWorkEntity( doc, *entity, text );
+    }
+
+    return result;
+}
+
+unsigned int RDFImpl::setWorkEntity(SPDocument * doc, struct rdf_work_entity_t & entity, const gchar * text)
+{
+    int result = 0;
+    if (!text || !text[0]) {
+        auto *item = const_cast<Inkscape::XML::Node *>(getWorkRepr(doc, entity.tag));
+        if (item) {
+            sp_repr_unparent(item);
+            if (!strcmp(entity.name, "title")) {
+                doc->getRoot()->setTitle(nullptr);
+            }
+        }
+        return true;
+    }
+
+    /*
+      printf("changing '%s' (%s) to '%s'\n",
+      entity->title,
+      entity->tag,
+      text);
+    */
+
+    Inkscape::XML::Node * item = ensureWorkRepr( doc, entity.tag );
+    if ( !item ) {
+        g_critical("Unable to get work element");
+    } else {
+        result = setReprText( item, entity, text );
+    }
+    return result;
+}
+
+
+#undef DEBUG_MATCH
+
+static bool
+rdf_match_license(Inkscape::XML::Node const *repr, struct rdf_license_t const *license)
+{
+    g_assert ( repr != nullptr );
+    g_assert ( license != nullptr );
+
+    bool result=TRUE;
+#ifdef DEBUG_MATCH
+    printf("checking against '%s'\n",license->name);
+#endif
+
+    int count = 0;
+    for (struct rdf_double_t const *details = license->details;
+         details->name; details++ ) {
+        count++;
+    }
+    bool * matched = (bool*)calloc(count,sizeof(bool));
+
+    for (Inkscape::XML::Node const *current = repr->firstChild();
+         current;
+         current = current->next() ) {
+
+        gchar const * attr = current->attribute("rdf:resource");
+        if ( attr == nullptr ) continue;
+
+#ifdef DEBUG_MATCH
+        printf("\texamining '%s' => '%s'\n", current->name(), attr);
+#endif
+
+        bool found_match=FALSE;
+        for (int i=0; i<count; i++) {
+            // skip already matched items
+            if (matched[i]) continue;
+
+#ifdef DEBUG_MATCH
+            printf("\t\t'%s' vs '%s'\n", current->name(), license->details[i].name);
+            printf("\t\t'%s' vs '%s'\n", attr, license->details[i].resource);
+#endif
+
+            if (!strcmp( current->name(),
+                         license->details[i].name ) &&
+                !strcmp( attr,
+                         license->details[i].resource )) {
+                matched[i]=TRUE;
+                found_match=TRUE;
+#ifdef DEBUG_MATCH
+                printf("\t\tgood!\n");
+#endif
+                break;
+            }
+        }
+        if (!found_match) {
+            // if we checked each known item of the license
+            // and didn't find it, we must abort
+            result=FALSE;
+#ifdef DEBUG_MATCH
+            printf("\t\tno '%s' element matched XML (bong)!\n",license->name);
+#endif
+            break;
+        }
+    }
+#ifdef DEBUG_MATCH
+    if (result) printf("\t\tall XML found matching elements!\n");
+#endif
+    for (int i=0; result && i<count; i++) {
+        // scan looking for an unmatched item
+        if (matched[i]==0) {
+            result=FALSE;
+#ifdef DEBUG_MATCH
+            printf("\t\tnot all '%s' elements used to match (bong)!\n", license->name);
+#endif
+        }
+    }
+
+#ifdef DEBUG_MATCH
+    printf("\t\tall '%s' elements used to match!\n",license->name);
+#endif
+
+    free(matched);
+
+#ifdef DEBUG_MATCH
+    if (result) printf("matched '%s'\n",license->name);
+#endif
+    return result;
+}
+
+// Public API:
+struct rdf_license_t *rdf_get_license(SPDocument *document)
+{
+    return RDFImpl::getLicense(document);
+}
+
+struct rdf_license_t *RDFImpl::getLicense(SPDocument *document)
+{
+    // Base license lookup on the URI of cc:license rather than the license
+    // properties, per instructions from the ccREL gurus.
+    // (Fixes https://bugs.launchpad.net/inkscape/+bug/372427)
+
+    struct rdf_work_entity_t *entity = rdf_find_entity("license_uri");
+    if (entity == nullptr) {
+        g_critical("Can't find internal entity structure for 'license_uri'");
+        return nullptr;
+    }
+
+    const gchar *uri = getWorkEntity(document, *entity);
+    struct rdf_license_t * license_by_uri = nullptr;
+
+    if (uri != nullptr) {
+        for (struct rdf_license_t * license = rdf_licenses; license->name; license++) {
+            if (g_strcmp0(uri, license->uri) == 0) {
+                license_by_uri = license;
+                break;
+            }
+        }
+    }
+
+    // To improve backward compatibility, the old license matching code is
+    // kept as fallback and to warn about and fix discrepancies.
+
+    // TODO: would it be better to do this code on document load?  Is
+    // sp_metadata_build() then the right place to put the call to sort out
+    // any RDF mess?
+
+    struct rdf_license_t * license_by_properties = nullptr;
+
+    Inkscape::XML::Node const *repr = getXmlRepr( document, XML_TAG_NAME_LICENSE );
+    if (repr) {
+        for ( struct rdf_license_t * license = rdf_licenses; license->name; license++ ) {
+            if ( rdf_match_license( repr, license ) ) {
+                license_by_properties = license;
+                break;
+            }
+        }
+    }
+
+    if (license_by_uri != nullptr && license_by_properties != nullptr) {
+        // Both property and structure, use property
+        if (license_by_uri != license_by_properties) {
+            // TODO: this should be a user-visible warning, but how?
+            g_warning("Mismatch between %s and %s metadata:\n"
+                      "%s value URI:   %s (using this one!)\n"
+                      "%s derived URI: %s",
+                      XML_TAG_NAME_LICENSE_PROP,
+                      XML_TAG_NAME_LICENSE,
+                      XML_TAG_NAME_LICENSE_PROP,
+                      license_by_uri->uri,
+                      XML_TAG_NAME_LICENSE,
+                      license_by_properties->uri);
+        }
+
+        // Reset license structure to match so the document is consistent
+        // (and this will also silence the warning above on repeated calls).
+        setLicense(document, license_by_uri);
+
+        return license_by_uri;
+    }
+    else if (license_by_uri != nullptr) {
+        // Only cc:license property, set structure for backward compatibility
+        setLicense(document, license_by_uri);
+
+        return license_by_uri;
+    }
+    else if (license_by_properties != nullptr) {
+        // Only cc:License structure
+        // TODO: this could be a user-visible warning too
+        g_warning("No %s metadata found, derived license URI from %s: %s",
+                  XML_TAG_NAME_LICENSE_PROP, XML_TAG_NAME_LICENSE,
+                  license_by_properties->uri);
+
+        // Set license property to match
+        setWorkEntity(document, *entity, license_by_properties->uri);
+
+        return license_by_properties;
+    }
+
+    // No license info at all
+    return nullptr;
+}
+
+// Public API:
+void rdf_set_license(SPDocument * doc, struct rdf_license_t const * license)
+{
+    RDFImpl::setLicense( doc, license );
+}
+
+void RDFImpl::setLicense(SPDocument * doc, struct rdf_license_t const * license)
+{
+    // When basing license check on only the license URI (see fix for
+    // https://bugs.launchpad.net/inkscape/+bug/372427 above) we should
+    // really drop this license section, but keep writing it for a while for
+    // compatibility with older versions.
+
+    // drop old license section
+    Inkscape::XML::Node * repr = getXmlRepr( doc, XML_TAG_NAME_LICENSE );
+    if (repr) {
+        sp_repr_unparent(repr);
+    }
+
+    if ( !license ) {
+        // All done
+    } else if ( !doc->getReprDoc() ) {
+        g_critical("XML doc is null.");
+    } else {
+        // build new license section
+        repr = ensureXmlRepr( doc, XML_TAG_NAME_LICENSE );
+        g_assert( repr );
+
+        repr->setAttribute("rdf:about", license->uri );
+
+        for (struct rdf_double_t const * detail = license->details; detail->name; detail++) {
+            Inkscape::XML::Node * child = doc->getReprDoc()->createElement( detail->name );
+            g_assert ( child != nullptr );
+
+            child->setAttribute("rdf:resource", detail->resource );
+            repr->appendChild(child);
+            Inkscape::GC::release(child);
+        }
+    }
+}
+
+// Public API:
+void rdf_set_defaults( SPDocument * doc )
+{
+    RDFImpl::setDefaults( doc );
+
+}
+
+void RDFImpl::setDefaults( SPDocument * doc )
+{
+    g_assert( doc != nullptr );
+
+    // Used to add hard coded defaults here
+}
+
+/*
+ * Add the metadata stored in the users preferences to the document if
+ *   a) the preference 'Input/Output->Add default metadata to new documents' is true, and
+ *   b) there is no metadata already in the file (such as from a template)
+ */
+void rdf_add_from_preferences(SPDocument *doc)
+{
+    Inkscape::Preferences *prefs = Inkscape::Preferences::get();
+    if (!prefs->getBool("/metadata/addToNewFile")) {
+        return;
+    }
+
+    // If there is already some metadata in the doc (from a template) don't add default metadata
+    for (struct rdf_work_entity_t *entity = rdf_work_entities; entity && entity->name; entity++) {
+        if ( entity->editable == RDF_EDIT_GENERIC &&
+                rdf_get_work_entity (doc, entity)) {
+            return;
+        }
+    }
+
+    // Put the metadata from user preferences into the doc
+    for (struct rdf_work_entity_t *entity = rdf_work_entities; entity && entity->name; entity++) {
+        if ( entity->editable == RDF_EDIT_GENERIC ) {
+            Glib::ustring text = prefs->getString(PREFS_METADATA + Glib::ustring(entity->name));
+            if (text.length() > 0) {
+                rdf_set_work_entity (doc, entity, text.c_str());
+            }
+        }
+    }
+}
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :