MT#60408 CallLeg: use dedicated fund to check expecting offer

Add a function to the AmSipDialog class interface,
to be able to check whether the OA currently expects an offer.

Use it then in the `CallLeg::updateLocalSdp(AmSdp &sdp)`

Change-Id: I1c4f4364ce13c7b03e22e0f037d19b99245a0be8

apps/sbc/CallLeg.cpp

@@ -1789,9 +1789,7 @@ void CallLeg::updateLocalSdp(AmSdp &sdp)
 
   // FIXME: repeated SDP (183, 200) will cause false match in OA_Completed
   // (need not to be expected with re-INVITEs asking for hold)
-  if (dlg->getOAState() == AmOfferAnswer::OA_None ||
-      dlg->getOAState() == AmOfferAnswer::OA_Completed)
-  {
+  if (dlg->oaExpectingOffer()) {
     // handling offer
     adjustOffer(sdp);
   }

core/AmSipDialog.cpp

@@ -223,6 +223,12 @@ void AmSipDialog::setOAState(AmOfferAnswer::OAState n_st) {
   oa.setState(n_st);
 }
 
+/** are we expecting to receive an SDP offer? */
+bool AmSipDialog::oaExpectingOffer() {
+  return oa.getState() == AmOfferAnswer::OA_None ||
+    oa.getState() == AmOfferAnswer::OA_Completed;
+}
+
 void AmSipDialog::setRel100State(Am100rel::State rel100_state) {
   DBG("setting 100rel state for '%s' to %i\n", local_tag.c_str(), rel100_state);
   rel100.setState(rel100_state);

core/AmSipDialog.h

@@ -112,6 +112,8 @@ protected:
   void setOAForceSDP(bool force) { oa.setForceSDP(force); }
   bool getOAForceSDP() const { return oa.getForceSDP(); }
 
+  bool oaExpectingOffer();
+
   /* getter/setter for faked 183 as 200OK responses, TT#187351 */
   void setFaked183As200(bool value) { faked_183_as_200 = value; }
   bool getFaked183As200() { return faked_183_as_200; }