Merge "Support INVITE w/o SDP."

voip/java/android/net/sip/SipAudioCall.java

@@ -26,6 +26,7 @@ import android.net.sip.SimpleSessionDescription.Media;
 import android.net.wifi.WifiManager;
 import android.os.Message;
 import android.os.RemoteException;
+import android.text.TextUtils;
 import android.util.Log;
 
 import java.io.IOException;
@@ -400,6 +401,7 @@ public class SipAudioCall {
             @Override
             public void onRinging(SipSession session,
                     SipProfile peerProfile, String sessionDescription) {
+                // this callback is triggered only for reinvite.
                 synchronized (SipAudioCall.this) {
                     if ((mSipSession == null) || !mInCall
                             || !session.getCallId().equals(
@@ -730,6 +732,7 @@ public class SipAudioCall {
     }
 
     private SimpleSessionDescription createAnswer(String offerSd) {
+        if (TextUtils.isEmpty(offerSd)) return createOffer();
         SimpleSessionDescription offer =
                 new SimpleSessionDescription(offerSd);
         SimpleSessionDescription answer =

voip/java/com/android/server/sip/SipSessionGroup.java

@@ -1007,7 +1007,13 @@ class SipSessionGroup implements SipListener {
                 throws SipException {
             // expect ACK, CANCEL request
             if (isRequestEvent(Request.ACK, evt)) {
-                establishCall(false);
+                String sdp = extractContent(((RequestEvent) evt).getRequest());
+                if (sdp != null) mPeerSessionDescription = sdp;
+                if (mPeerSessionDescription == null) {
+                    onError(SipErrorCode.CLIENT_ERROR, "peer sdp is empty");
+                } else {
+                    establishCall(false);
+                }
                 return true;
             } else if (isRequestEvent(Request.CANCEL, evt)) {
                 // http://tools.ietf.org/html/rfc3261#section-9.2