Polishing

spring-tx/src/main/java/org/springframework/transaction/annotation/Propagation.java

@@ -87,11 +87,11 @@ public enum Propagation {
 
 	/**
 	 * Execute within a nested transaction if a current transaction exists,
-	 * behave like {@code REQUIRED} else. There is no analogous feature in EJB.
+	 * behave like {@code REQUIRED} otherwise. There is no analogous feature in EJB.
 	 * <p>Note: Actual creation of a nested transaction will only work on specific
 	 * transaction managers. Out of the box, this only applies to the JDBC
-	 * DataSourceTransactionManager when working on a JDBC 3.0 driver.
-	 * Some JTA providers might support nested transactions as well.
+	 * DataSourceTransactionManager. Some JTA providers might support nested
+	 * transactions as well.
 	 * @see org.springframework.jdbc.datasource.DataSourceTransactionManager
 	 */
 	NESTED(TransactionDefinition.PROPAGATION_NESTED);

spring-tx/src/main/java/org/springframework/transaction/support/AbstractPlatformTransactionManager.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2018 the original author or authors.
+ * Copyright 2002-2019 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -553,7 +553,7 @@ public abstract class AbstractPlatformTransactionManager implements PlatformTran
 		if (definition.getTimeout() != TransactionDefinition.TIMEOUT_DEFAULT) {
 			return definition.getTimeout();
 		}
-		return this.defaultTimeout;
+		return getDefaultTimeout();
 	}
 
 
@@ -1099,6 +1099,8 @@ public abstract class AbstractPlatformTransactionManager implements PlatformTran
 	 * @param definition a TransactionDefinition instance, describing propagation
 	 * behavior, isolation level, read-only flag, timeout, and transaction name
 	 * @throws TransactionException in case of creation or system errors
+	 * @throws org.springframework.transaction.NestedTransactionNotSupportedException
+	 * if the underlying transaction does not support nesting
 	 */
 	protected abstract void doBegin(Object transaction, TransactionDefinition definition)
 			throws TransactionException;

spring-tx/src/main/java/org/springframework/transaction/support/TransactionSynchronizationManager.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2019 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -292,10 +292,11 @@ public abstract class TransactionSynchronizationManager {
 			throws IllegalStateException {
 
 		Assert.notNull(synchronization, "TransactionSynchronization must not be null");
-		if (!isSynchronizationActive()) {
+		Set<TransactionSynchronization> synchs = synchronizations.get();
+		if (synchs == null) {
 			throw new IllegalStateException("Transaction synchronization is not active");
 		}
-		synchronizations.get().add(synchronization);
+		synchs.add(synchronization);
 	}
 
 	/**