Pass the error to inject_listener_closed method (#1517)

* Pass the error to inject_listener_closed method

If there is an error when the listener closes, found in the
`NetworkEvent::ListenerClosed` `reason` field, we would like to pass it
on to the `inject_listener_closed()` method so that implementors of this
method have access to it.

Add an error parameter to `inject_listener_closed`.  Convert the
`reason` field from a `Result` to an `Option` and if there is an error
pass `Some(error)` at the method call site.

* Pass 'reason' as a Result

* Finish change

Co-authored-by: Pierre Krieger <pierre.krieger1708@gmail.com>

misc/core-derive/src/lib.rs

@@ -271,8 +271,8 @@ fn build_struct(ast: &DeriveInput, data_struct: &DataStruct) -> TokenStream {
                 return None
             }
             Some(match field.ident {
-                Some(ref i) => quote!(self.#i.inject_listener_closed(id);),
+                Some(ref i) => quote!(self.#i.inject_listener_closed(id, reason);),
-                None => quote!(self.#field_n.inject_listener_closed(id);)
+                None => quote!(self.#field_n.inject_listener_closed(id, reason);)
             })
         })
     };
@@ -469,7 +469,7 @@ fn build_struct(ast: &DeriveInput, data_struct: &DataStruct) -> TokenStream {
                 #(#inject_listener_error_stmts);*
             }
 
-            fn inject_listener_closed(&mut self, id: #listener_id) {
+            fn inject_listener_closed(&mut self, id: #listener_id, reason: Result<(), &std::io::Error>) {
                 #(#inject_listener_closed_stmts);*
             }
 

swarm/src/behaviour.rs

@@ -146,7 +146,7 @@ pub trait NetworkBehaviour: Send + 'static {
     }
 
     /// A listener closed.
-    fn inject_listener_closed(&mut self, _id: ListenerId) {
+    fn inject_listener_closed(&mut self, _id: ListenerId, _reason: Result<(), &std::io::Error>) {
     }
 
     /// Polls for things that swarm should do.
@@ -304,4 +304,3 @@ impl Default for DialPeerCondition {
         DialPeerCondition::Disconnected
     }
 }
-

swarm/src/lib.rs

@@ -593,7 +593,10 @@ where TBehaviour: NetworkBehaviour<ProtocolsHandler = THandler>,
                     for addr in addresses.iter() {
                         this.behaviour.inject_expired_listen_addr(addr);
                     }
-                    this.behaviour.inject_listener_closed(listener_id);
+                    this.behaviour.inject_listener_closed(listener_id, match &reason {
+                        Ok(()) => Ok(()),
+                        Err(err) => Err(err),
+                    });
                     return Poll::Ready(SwarmEvent::ListenerClosed {
                         addresses,
                         reason,