From b5d31a8c83b0cc92710ef7ce6837c5eae6e7425d Mon Sep 17 00:00:00 2001
From: Julien Ponge <jponge@redhat.com>
Date: Thu, 14 Mar 2024 15:32:45 +0100
Subject: [PATCH] Add a C&S step for CompletionStagePublisher cancellation

We're observing some RS TCK failures in slow CI conditions.
---
 .../java/mutiny/zero/internal/CompletionStagePublisher.java  | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/mutiny-zero/src/main/java/mutiny/zero/internal/CompletionStagePublisher.java b/mutiny-zero/src/main/java/mutiny/zero/internal/CompletionStagePublisher.java
index ede1a3d..f5f71ea 100644
--- a/mutiny-zero/src/main/java/mutiny/zero/internal/CompletionStagePublisher.java
+++ b/mutiny-zero/src/main/java/mutiny/zero/internal/CompletionStagePublisher.java
@@ -86,8 +86,9 @@ public void request(long n) {
 
         @Override
         public void cancel() {
-            cancelled.set(true);
-            completableFuture.toCompletableFuture().cancel(false);
+            if (cancelled.compareAndSet(false, true)) {
+                completableFuture.toCompletableFuture().cancel(false);
+            }
         }
     }
 }