Fix dirty flag set to false on same value put

spring-batch-infrastructure/src/main/java/org/springframework/batch/item/ExecutionContext.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2006-2023 the original author or authors.
+ * Copyright 2006-2024 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.
@@ -37,6 +37,7 @@
  * @author Lucas Ward
  * @author Douglas Kaminsky
  * @author Mahmoud Ben Hassine
+ * @author Seokmun Heo
  */
 public class ExecutionContext implements Serializable {
 
@@ -124,7 +125,11 @@ public void putDouble(String key, double value) {
 	public void put(String key, @Nullable Object value) {
 		if (value != null) {
 			Object result = this.map.put(key, value);
-			this.dirty = result == null || !result.equals(value);
+			boolean newDirty = result == null || !result.equals(value);
+
+			if (!this.dirty) {
+				this.dirty = newDirty;
+			}
 		}
 		else {
 			Object result = this.map.remove(key);

spring-batch-infrastructure/src/test/java/org/springframework/batch/item/ExecutionContextTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2006-2023 the original author or authors.
+ * Copyright 2006-2024 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.
@@ -30,7 +30,7 @@
 /**
  * @author Lucas Ward
  * @author Mahmoud Ben Hassine
- *
+ * @author Seokmun Heo
  */
 class ExecutionContextTests {
 
@@ -161,6 +161,15 @@ void testCopyConstructorNullInput() {
 		assertTrue(context.isEmpty());
 	}
 
+	@Test
+	void testDirtyWithDuplicate() {
+		ExecutionContext context = new ExecutionContext();
+		context.put("1", "testString1");
+		assertTrue(context.isDirty());
+		context.put("1", "testString1"); // put the same value
+		assertTrue(context.isDirty());
+	}
+
 	/**
 	 * Value object for testing serialization
 	 */