HTTPCLIENT-2231: a race condition in the main async exec when the request execution on an I/O thread is faster then execution pipeline management on the client thread

httpclient5/src/main/java/org/apache/hc/client5/http/impl/async/HttpAsyncMainClientExec.java

@@ -133,7 +133,9 @@ class HttpAsyncMainClientExec implements AsyncExecChainHandler {
 
             @Override
             public void cancel() {
-                failed(new InterruptedIOException());
+                if (messageCountDown.get() > 0) {
+                    failed(new InterruptedIOException());
+                }
             }
 
             @Override