[trac1061] Don't return reference

While it works for in-memory zone and similar, it can't be done with
databases, as the database returns some primitive data and it must be
created on the spot.

src/bin/auth/tests/query_unittest.cc

@@ -122,8 +122,8 @@ public:
         masterLoad(zone_stream, origin_, rrclass_,
                    boost::bind(&MockZoneFinder::loadRRset, this, _1));
     }
-    virtual const isc::dns::Name& getOrigin() const { return (origin_); }
-    virtual const isc::dns::RRClass& getClass() const { return (rrclass_); }
+    virtual isc::dns::Name getOrigin() const { return (origin_); }
+    virtual isc::dns::RRClass getClass() const { return (rrclass_); }
     virtual FindResult find(const isc::dns::Name& name,
                             const isc::dns::RRType& type,
                             RRsetList* target = NULL,

src/lib/datasrc/database.h

@@ -139,8 +139,8 @@ public:
          *     calls to the connection.
          */
         Finder(DatabaseConnection& connection, int zone_id);
-        virtual const isc::dns::Name& getOrigin() const;
-        virtual const isc::dns::RRClass& getClass() const;
+        virtual isc::dns::Name getOrigin() const;
+        virtual isc::dns::RRClass getClass() const;
         virtual FindResult find(const isc::dns::Name& name,
                                 const isc::dns::RRType& type,
                                 isc::dns::RRsetList* target = NULL,

src/lib/datasrc/memory_datasrc.cc

@@ -606,12 +606,12 @@ InMemoryZoneFinder::~InMemoryZoneFinder() {
     delete impl_;
 }
 
-const Name&
+Name
 InMemoryZoneFinder::getOrigin() const {
     return (impl_->origin_);
 }
 
-const RRClass&
+RRClass
 InMemoryZoneFinder::getClass() const {
     return (impl_->zone_class_);
 }

src/lib/datasrc/memory_datasrc.h

@@ -58,10 +58,10 @@ public:
     //@}
 
     /// \brief Returns the origin of the zone.
-    virtual const isc::dns::Name& getOrigin() const;
+    virtual isc::dns::Name getOrigin() const;
 
     /// \brief Returns the class of the zone.
-    virtual const isc::dns::RRClass& getClass() const;
+    virtual isc::dns::RRClass getClass() const;
 
     /// \brief Looks up an RRset in the zone.
     ///

src/lib/datasrc/zone.h

@@ -131,10 +131,10 @@ public:
     /// These methods should never throw an exception.
     //@{
     /// Return the origin name of the zone.
-    virtual const isc::dns::Name& getOrigin() const = 0;
+    virtual isc::dns::Name getOrigin() const = 0;
 
     /// Return the RR class of the zone.
-    virtual const isc::dns::RRClass& getClass() const = 0;
+    virtual isc::dns::RRClass getClass() const = 0;
     //@}
 
     ///