Answers a "not implemented" error when the IQ is not understood

git-svn-id: http://svn.igniterealtime.org/svn/repos/smack/trunk@2220 b35dd754-fafc-0310-a699-88a17e54d16e

source/org/jivesoftware/smack/PacketReader.java

@@ -407,8 +407,26 @@ class PacketReader {
                 }
             }
         }
-        // Set basic values on the iq packet.
+        // Decide what to do when an IQ packet was not understood 
         if (iqPacket == null) {
+            if (IQ.Type.GET == type || IQ.Type.SET == type ) {
+                // If the IQ stanza is of type "get" or "set" containing a child element 
+                // qualified by a namespace it does not understand, then answer an IQ of 
+                // type "error" with code 501 ("feature-not-implemented")
+                iqPacket = new IQ() {
+                    public String getChildElementXML() {
+                        return null;
+                    }
+                };
+                iqPacket.setPacketID(id);
+                iqPacket.setTo(from);
+                iqPacket.setFrom(to);
+                iqPacket.setType(IQ.Type.ERROR);
+                iqPacket.setError(new XMPPError(501, "feature-not-implemented"));
+                connection.sendPacket(iqPacket);
+                return null;
+            }
+            else {
                 // If an IQ packet wasn't created above, create an empty IQ packet.
                 iqPacket = new IQ() {
                     public String getChildElementXML() {
@@ -416,6 +434,9 @@ class PacketReader {
                     }
                 };
             }
+        }
+        
+        // Set basic values on the iq packet.
         iqPacket.setPacketID(id);
         iqPacket.setTo(to);
         iqPacket.setFrom(from);