Only show Introduction Accept Information if success is still possible

briar-core/src/main/java/org/briarproject/briar/introduction/AbstractProtocolEngine.java

@@ -149,11 +149,12 @@ abstract class AbstractProtocolEngine<S extends Session>
 			throws DbException {
 		AuthorId localAuthorId = identityManager.getLocalAuthor(txn).getId();
 		Contact c = contactManager.getContact(txn, sender, localAuthorId);
+		boolean possible = s.getState().successPossible();
 		IntroductionResponse response =
 				new IntroductionResponse(s.getSessionId(), m.getMessageId(),
 						m.getGroupId(), s.getRole(), m.getTimestamp(), false,
 						false, false, false, otherAuthor.getName(),
-						m instanceof AcceptMessage);
+						m instanceof AcceptMessage, possible);
 		IntroductionResponseReceivedEvent e =
 				new IntroductionResponseReceivedEvent(c.getId(), response);
 		txn.attach(e);

briar-core/src/main/java/org/briarproject/briar/introduction/IntroduceeState.java

@@ -34,4 +34,10 @@ enum IntroduceeState implements State {
 		throw new FormatException();
 	}
 
+	@Override
+	public boolean successPossible() {
+		return this != START && this != LOCAL_DECLINED &&
+				this != REMOTE_DECLINED;
+	}
+
 }

briar-core/src/main/java/org/briarproject/briar/introduction/IntroducerState.java

@@ -34,4 +34,9 @@ enum IntroducerState implements State {
 		throw new FormatException();
 	}
 
+	@Override
+	public boolean successPossible() {
+		return this != START && this != A_DECLINED && this != B_DECLINED;
+	}
+
 }

briar-core/src/main/java/org/briarproject/briar/introduction/IntroductionManagerImpl.java

@@ -470,6 +470,7 @@ class IntroductionManagerImpl extends ConversationClientImpl
 		Role role = sessionParser.getRole(bdfSession);
 		SessionId sessionId;
 		Author author;
+		boolean successPossible;
 		if (role == INTRODUCER) {
 			IntroducerSession session =
 					sessionParser.parseIntroducerSession(bdfSession);
@@ -479,15 +480,18 @@ class IntroductionManagerImpl extends ConversationClientImpl
 			} else {
 				author = session.getIntroduceeA().author;
 			}
+			successPossible = session.getState().successPossible();
 		} else if (role == INTRODUCEE) {
 			IntroduceeSession session = sessionParser
 					.parseIntroduceeSession(contactGroupId, bdfSession);
 			sessionId = session.getSessionId();
 			author = session.getRemote().author;
+			successPossible = session.getState().successPossible();
 		} else throw new AssertionError();
 		return new IntroductionResponse(sessionId, m, contactGroupId,
 				role, meta.getTimestamp(), meta.isLocal(), status.isSent(),
-				status.isSeen(), meta.isRead(), author.getName(), accept);
+				status.isSeen(), meta.isRead(), author.getName(), accept,
+				successPossible);
 	}
 
 	private void removeSessionWithIntroducer(Transaction txn,

briar-core/src/main/java/org/briarproject/briar/introduction/State.java

@@ -4,4 +4,6 @@ interface State {
 
 	int getValue();
 
+	boolean successPossible();
+
 }

briar-core/src/test/java/org/briarproject/briar/introduction/IntroductionIntegrationTest.java

@@ -415,8 +415,8 @@ public class IntroductionIntegrationTest
 		eventWaiter.await(TIMEOUT, 1);
 		assertTrue(listener0.response2Received);
 
-		// Forward AUTH
-		sync0To1(1, true);
+		// Forward AUTH and response
+		sync0To1(2, true);
 
 		// Second AUTH and ACTIVATE and forward them
 		sync1To0(2, true);