Merge pull request RestComm#13 from gfigiel/Issue#12-SessionIDonceonly

Guarantee only 1 occurrence of Session-Id will be present at message when adding it.

Fixes RestComm#12

resources/diameter-base/common/events/src/main/java/net/java/slee/resource/diameter/base/events/avp/AvpUtilities.java

@@ -52,6 +52,7 @@
  * 
  * @author <a href="mailto:[email protected]"> Bartosz Baranowski </a>
  * @author <a href="mailto:[email protected]"> Alexandre Mendonca </a>
+ * @author <a href="mailto:[email protected]"> Grzegorz Figiel (ProIDS sp. z o.o.)</a>
  */
 public class AvpUtilities {
 
@@ -224,6 +225,8 @@ public static void setAvpAsString(Object parent, int avpCode, long vendorId, boo
 
  switch(avpCode) {
  case Avp.SESSION_ID:
+ //(...) All messages pertaining to a specific session MUST include only one Session-Id AVP (...)
+ set.removeAvp(avpCode);
  // (...) the Session-Id SHOULD appear immediately following the Diameter Header
  set.insertAvp(0, avpCode, value, vendorId, isMandatory, isProtected, isOctetString);
  break;
@@ -476,6 +479,8 @@ public static void setAvpAsUTF8String(Object parent, int avpCode, long vendorId,
 
  switch(avpCode) {
  case Avp.SESSION_ID:
+ //(...) All messages pertaining to a specific session MUST include only one Session-Id AVP (...)
+ set.removeAvp(avpCode);
  // (...) the Session-Id SHOULD appear immediately following the Diameter Header
  set.insertAvp(0, avpCode, value, vendorId, isMandatory, isProtected, false);
  break;
@@ -1601,6 +1606,8 @@ public static void setAvpAsRaw(Object parent, int avpCode, long vendorId, AvpSet
 
  switch(avpCode) {
  case Avp.SESSION_ID:
+ //(...) All messages pertaining to a specific session MUST include only one Session-Id AVP (...)
+ set.removeAvp(avpCode);
  // (...) the Session-Id SHOULD appear immediately following the Diameter Header
  set.insertAvp(0, avpCode, value, vendorId, isMandatory, isProtected);
  break;
@@ -2216,9 +2223,11 @@ private static void addAvpInternal(DiameterAvp avp, AvpSet set) {
  }
  else {
  switch (avpCode) {
- case Avp.SESSION_ID: 
- // (...) the Session-Id SHOULD appear immediately following the Diameter Header
- set.insertAvp(0, avpCode, avp.byteArrayValue(), avp.getVendorId(), avp.getMandatoryRule() != DiameterAvp.FLAG_RULE_MUSTNOT, avp.getProtectedRule() == DiameterAvp.FLAG_RULE_MUST);
+ case Avp.SESSION_ID:
+ //(...) All messages pertaining to a specific session MUST include only one Session-Id AVP (...)
+ set.removeAvp(avpCode);
+ // (...) the Session-Id SHOULD appear immediately following the Diameter Header
+ set.insertAvp(0, avpCode, avp.byteArrayValue(), avp.getVendorId(), avp.getMandatoryRule() != DiameterAvp.FLAG_RULE_MUSTNOT, avp.getProtectedRule() == DiameterAvp.FLAG_RULE_MUST);
  break;
  case Avp.ORIGIN_HOST: 
  case Avp.ORIGIN_REALM: