* #15545: sip: restore old Call API but handle invite with no SDP correctly

daemon/src/call.h

@@ -173,6 +173,8 @@ class Call : public Recordable {
             isIPToIP_ = IPToIP;
         }
 
+        virtual void answer() = 0;
+
         /**
          * Set my IP [not protected]
          * @param ip  The local IP address

daemon/src/iax/iaxcall.h

@@ -71,11 +71,11 @@ class IAXCall : public Call {
 
         int getAudioCodec() const;
 
-        void answer();
-
         int format;
         iax_session* session;
     private:
+        void answer();
+
         NON_COPYABLE(IAXCall);
 };
 

daemon/src/iax/iaxvoiplink.cpp

@@ -278,7 +278,7 @@ IAXVoIPLink::answer(Call *call)
     Manager::instance().addStream(call->getCallId());
 
     mutexIAX_.enter();
-    static_cast<IAXCall*>(call)->answer();
+    call->answer();
     mutexIAX_.leave();
 
     call->setState(Call::ACTIVE);

daemon/src/sip/sipcall.cpp

@@ -62,13 +62,14 @@ SIPCall::~SIPCall()
     pj_pool_release(pool_);
 }
 
-void SIPCall::answer(bool needsSdp)
+void SIPCall::answer()
 {
     pjsip_tx_data *tdata;
     if (!inv->last_answer)
         throw std::runtime_error("Should only be called for initial answer");
 
-    if (pjsip_inv_answer(inv, PJSIP_SC_OK, NULL, needsSdp ? local_sdp_->getLocalSdpSession() : NULL, &tdata) != PJ_SUCCESS)
+    // answer with SDP if no SDP was given in initial invite (i.e. inv->neg is NULL)
+    if (pjsip_inv_answer(inv, PJSIP_SC_OK, NULL, !inv->neg ? local_sdp_->getLocalSdpSession() : NULL, &tdata) != PJ_SUCCESS)
         throw std::runtime_error("Could not init invite request answer (200 OK)");
 
     if (pjsip_inv_send_msg(inv, tdata) != PJ_SUCCESS)

daemon/src/sip/sipcall.h

@@ -100,9 +100,7 @@ class SIPCall : public Call {
             return pool_;
         }
 
-        // @param needsSdp: true if the invite was received without an SDP
-        // and thus one must been added, false otherwise
-        void answer(bool needsSdp);
+        void answer();
 
         /**
          * The invite session to be reused in case of transfer

daemon/src/sip/sipvoiplink.cpp

@@ -913,15 +913,13 @@ SIPVoIPLink::answer(Call *call)
         return;
 
     SIPCall *sipCall = static_cast<SIPCall*>(call);
-    bool needsSdp = false;
     if (!sipCall->inv->neg) {
         WARN("Negotiator is NULL, we've received an INVITE without an SDP");
         pjmedia_sdp_session *dummy;
         sdp_create_offer_cb(sipCall->inv, &dummy);
-        needsSdp = true;
     }
 
-    sipCall->answer(needsSdp);
+    call->answer();
 }
 
 namespace {