Exception for OSIV deferred close with async requests

OSIV deferred close mode is not supported with async requests and is
unlikely to be what's the desired. This change adds an exception with
a message stating this.

Issue: SPR-8517

Author: rstoyanchev

spring-orm/src/main/java/org/springframework/orm/hibernate3/support/OpenSessionInViewFilter.java

@@ -218,6 +218,9 @@ protected void doFilterInternal(
 					closeSession(sessionHolder.getSession(), sessionFactory);
 				}
 				else {
+					if (chain.isAsyncStarted()) {
+						throw new IllegalStateException("Deferred close is not supported with async requests.");
+					}
 					// deferred close mode
 					SessionFactoryUtils.processDeferredClose(sessionFactory);
 				}

spring-orm/src/main/java/org/springframework/orm/hibernate3/support/OpenSessionInViewInterceptor.java

@@ -193,8 +193,13 @@ public Object call() throws Exception {
 	 */
 	public void postHandleAsyncStarted(WebRequest request) {
 		String attributeName = getParticipateAttributeName();
-		if ((request.getAttribute(attributeName, WebRequest.SCOPE_REQUEST) == null) && isSingleSession()) {
-			TransactionSynchronizationManager.unbindResource(getSessionFactory());
+		if (request.getAttribute(attributeName, WebRequest.SCOPE_REQUEST) == null) {
+			if (isSingleSession()) {
+				TransactionSynchronizationManager.unbindResource(getSessionFactory());
+			}
+			else {
+				throw new IllegalStateException("Deferred close is not supported with async requests.");
+			}
 		}
 	}