Check dirty flag of step execution context before update in inner loop

Author: hpoettker

spring-batch-core/src/main/java/org/springframework/batch/core/step/tasklet/TaskletStep.java

@@ -425,7 +425,9 @@ public RepeatStatus doInTransaction(TransactionStatus status) {
 				try {
 					// Going to attempt a commit. If it fails this flag will
 					// stay false and we can use that later.
-					getJobRepository().updateExecutionContext(stepExecution);
+					if (stepExecution.getExecutionContext().isDirty()) {
+						getJobRepository().updateExecutionContext(stepExecution);
+					}
 					stepExecution.incrementCommitCount();
 					if (logger.isDebugEnabled()) {
 						logger.debug("Saving step execution before commit: " + stepExecution);