Added coverage specific metadata in Capabilities responses using the …

…'metadatalink_href', 'metadatalink_type' and 'metadatalink_format' entries. See issue #4306.

mapwcs20.c

@@ -2932,9 +2932,13 @@ static int msWCSGetCapabilities20_CoverageSummary(
 {
     wcs20coverageMetadataObj cm;
     int status;
-    xmlNodePtr psCSummary;
+    xmlNodePtr psCSummary, psMetadata;
+    const char *metadatalink_href = msOWSLookupMetadata(&(layer->metadata), "CO", "metadatalink_href");
+
 
     xmlNsPtr psWcsNs = xmlSearchNs( doc, xmlDocGetRootElement(doc), BAD_CAST "wcs" );
+    xmlNsPtr psOwsNs = xmlSearchNs( doc, xmlDocGetRootElement(doc), BAD_CAST "ows" );
+    xmlNsPtr psXlinkNs = xmlSearchNs( doc, xmlDocGetRootElement(doc), BAD_CAST "xlink" );
 
     status = msWCSGetCoverageMetadata20(layer, &cm);
     if(status != MS_SUCCESS) return MS_FAILURE;
@@ -2943,6 +2947,25 @@ static int msWCSGetCapabilities20_CoverageSummary(
     xmlNewChild(psCSummary, psWcsNs, BAD_CAST "CoverageId", BAD_CAST layer->name);
     xmlNewChild(psCSummary, psWcsNs, BAD_CAST "CoverageSubtype", BAD_CAST "RectifiedGridCoverage");
 
+    /* Add references to additional coverage metadata */
+    if (metadatalink_href != NULL)
+    {
+        const char *metadatalink_type = msOWSLookupMetadata(&(layer->metadata), "CO", "metadatalink_type");
+        const char *metadatalink_format = msOWSLookupMetadata(&(layer->metadata), "CO", "metadatalink_format");
+
+        psMetadata = xmlNewChild(psCSummary, psOwsNs, BAD_CAST "Metadata", NULL);
+        xmlNewNsProp(psMetadata, psXlinkNs, BAD_CAST "type", BAD_CAST "simple");
+        xmlNewNsProp(psMetadata, psXlinkNs, BAD_CAST "href", BAD_CAST metadatalink_href);
+        if (metadatalink_type != NULL)
+        {
+            xmlNewProp(psMetadata, BAD_CAST "about", BAD_CAST metadatalink_type);
+        }
+        if (metadatalink_format != NULL)
+        {
+            xmlNewNsProp(psMetadata, psXlinkNs, BAD_CAST "role", BAD_CAST metadatalink_format);
+        }
+    }
+
     msWCSClearCoverageMetadata20(&cm);
 
     return MS_SUCCESS;