From b58ff91864890a1c7008b4884bcbcc7759257fff Mon Sep 17 00:00:00 2001
From: Thibault Wittemberg <twittemberg@genetec.com>
Date: Mon, 11 Apr 2022 11:44:30 +0200
Subject: [PATCH] asyncChannel: fixes potential crashes when no more awaiting

This commit fixes crashes where the state is "awaiting" with no more awaiting clients.
The state is now set to .idle to reflect the reality.
---
 Sources/AsyncAlgorithms/AsyncChannel.swift | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/Sources/AsyncAlgorithms/AsyncChannel.swift b/Sources/AsyncAlgorithms/AsyncChannel.swift
index c256fd09..f6d132f4 100644
--- a/Sources/AsyncAlgorithms/AsyncChannel.swift
+++ b/Sources/AsyncAlgorithms/AsyncChannel.swift
@@ -89,7 +89,11 @@ public final class AsyncChannel<Element: Sendable>: AsyncSequence, Sendable {
       switch self {
       case .awaiting(var awaiting):
         let continuation = awaiting.remove(Awaiting(placeholder: generation))?.continuation
-        self = .awaiting(awaiting)
+        if awaiting.isEmpty {
+          self = .idle
+        } else {
+          self = .awaiting(awaiting)
+        }
         return continuation
       case .idle:
         self = .awaiting([Awaiting(cancelled: generation)])
@@ -145,7 +149,11 @@ public final class AsyncChannel<Element: Sendable>: AsyncSequence, Sendable {
             nexts.remove(Awaiting(placeholder: generation))
             cancelled = true
           }
-          state.emission = .awaiting(nexts)
+          if nexts.isEmpty {
+            state.emission = .idle
+          } else {
+            state.emission = .awaiting(nexts)
+          }
           return nil
         }
       }?.resume()