Patched to fix XML catalog access for DTD validation and prevent excessive memory usage at validation time.

src/xmlcopyeditor.cpp

@@ -3773,13 +3773,17 @@ void MyFrame::OnValidateSchema ( wxCommandEvent& event )
     // branch: if no XML Schema found, use LibXML DTD parser instead
     // so the catalog is read - switch when Xerces-C implements
     // XMLCatalogResolver
+    {
       std::string rawBuffer, schemaLocation;
       getRawText ( doc, rawBuffer );
       auto_ptr<XmlSchemaLocator> xsl (new XmlSchemaLocator() );
       xsl->parse ( rawBuffer.c_str() );
       if ( ( xsl->getSchemaLocation() ) . empty() )
+      {
          OnValidateDTD ( event );
-    // end of branch
+	 return;
+      }
+    }
 
     wxString fileName;
     std::string tempFileNameLocal;