Fix dtls role based on ice role

Author: Oto Dušek

webrtc/src/peer_connection/mod.rs

@@ -907,9 +907,14 @@ impl RTCPeerConnection {
         _options: Option<RTCAnswerOptions>,
     ) -> Result<RTCSessionDescription> {
         let use_identity = self.idp_login_url.is_some();
-        if self.remote_description().await.is_none() {
+        let remote_desc = self.remote_description().await;
+        let remote_description: RTCSessionDescription;
+        if let Some(desc) = remote_desc {
+            remote_description = desc;
+        }else{
             return Err(Error::ErrNoRemoteDescription);
-        } else if use_identity {
+        }
+        if use_identity {
             return Err(Error::ErrIdentityProviderNotImplemented);
         } else if self.internal.is_closed.load(Ordering::SeqCst) {
             return Err(Error::ErrConnectionClosed);
@@ -926,8 +931,10 @@ impl RTCPeerConnection {
             .to_connection_role();
         if connection_role == ConnectionRole::Unspecified {
             connection_role = DEFAULT_DTLS_ROLE_ANSWER.to_connection_role();
-            if remote_is_lite && !self.internal.setting_engine.candidates.ice_lite {
-                connection_role = DTLSRole::Server.to_connection_role();
+            if let  Some(parsed) = remote_description.parsed {
+                if Self::is_lite_set(&parsed) && !self.internal.setting_engine.candidates.ice_lite {
+                    connection_role = DTLSRole::Server.to_connection_role();
+                }
             }
         }
 
@@ -1299,6 +1306,15 @@ impl RTCPeerConnection {
         self.current_local_description().await
     }
 
+    pub fn is_lite_set(desc: &SessionDescription) -> bool{
+        for a in &desc.attributes {
+            if a.key.trim() == ATTR_KEY_ICELITE {
+                return true;
+            }
+        }
+        return false;
+    }
+
     /// set_remote_description sets the SessionDescription of the remote peer
     pub async fn set_remote_description(&self, mut desc: RTCSessionDescription) -> Result<()> {
         if self.internal.is_closed.load(Ordering::SeqCst) {
@@ -1518,13 +1534,7 @@ impl RTCPeerConnection {
                 return Ok(());
             }
 
-            let mut remote_is_lite = false;
-            for a in &parsed.attributes {
-                if a.key.trim() == ATTR_KEY_ICELITE {
-                    remote_is_lite = true;
-                    break;
-                }
-            }
+            let remote_is_lite = Self::is_lite_set(parsed);
 
             let (fingerprint, fingerprint_hash) = extract_fingerprint(parsed)?;