Add check for Long.MAX_VALUE

Issue: SPR-15203

spring-web/src/main/java/org/springframework/http/server/reactive/AbstractListenerReadPublisher.java

@@ -116,10 +116,13 @@ public abstract class AbstractListenerReadPublisher<T> implements Publisher<T> {
 	 * @return {@code true} if there is more demand; {@code false} otherwise
 	 */
 	private boolean readAndPublish() throws IOException {
-		while (hasDemand()) {
+		long r;
+		while ((r = demand) > 0) {
 			T data = read();
 			if (data != null) {
-				Operators.addAndGet(DEMAND_FIELD_UPDATER, this, -1L);
+				if (r != Long.MAX_VALUE) {
+					DEMAND_FIELD_UPDATER.addAndGet(this, -1L);
+				}
 				this.subscriber.onNext(data);
 			}
 			else {
@@ -129,10 +132,6 @@ public abstract class AbstractListenerReadPublisher<T> implements Publisher<T> {
 		return false;
 	}
 
-	private boolean hasDemand() {
-		return (this.demand > 0);
-	}
-
 	private boolean changeState(State oldState, State newState) {
 		return this.state.compareAndSet(oldState, newState);
 	}