Protect JMS connection creation against prepareConnection errors

This commit uses a local variable for the creation of a new JMS
Connection so that a rare failure in prepareConnection(...) does not
leave the connection field in a partially initialized state.

If such a JMSException occurs, the intermediary connection is closed.
This commit further defends against close() failures at that point,
by logging the close exception at DEBUG level. As a result, the original
JMSException is always re-thrown.

Closes gh-29116
See gh-29115

spring-jms/src/main/java/org/springframework/jms/connection/SingleConnectionFactory.java

@@ -346,8 +346,26 @@ public class SingleConnectionFactory implements ConnectionFactory, QueueConnecti
 			if (this.connection != null) {
 				closeConnection(this.connection);
 			}
-			this.connection = doCreateConnection();
-			prepareConnection(this.connection);
+			// Create new (method local) connection, which is later assigned to instance connection
+			//  - prevention to hold instance connection without exception listener, in case when
+			//    some subsequent methods (after creation of connection) throws JMSException
+			Connection con = doCreateConnection();
+			try {
+				prepareConnection(con);
+				this.connection = con;
+			}
+			catch (JMSException ex) {
+				// Attempt to close new (not used) connection to release possible resources
+				try {
+					con.close();
+				}
+				catch(Throwable th) {
+					if (logger.isDebugEnabled()) {
+						logger.debug("Could not close newly obtained JMS Connection that failed to prepare", th);
+					}
+				}
+				throw ex;
+			}
 			if (this.startedCount > 0) {
 				this.connection.start();
 			}