Fix dirty flag on ExecutionContext

Before this commit, the dirty flag was reset
on any put operation, even those that replace
existing keys with the same values.

This commit fixes the dirty flag to be cleared
only by meaningful put operations.

Resolves #4685
Resolves #4692

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 2006-2025 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 {
 
@@ -124,19 +125,21 @@ 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);
+			this.dirty = this.dirty || result == null || !result.equals(value);
 		}
 		else {
 			Object result = this.map.remove(key);
-			this.dirty = result != null;
+			this.dirty = this.dirty || result != null;
 		}
 	}
 
 	/**
 	 * Indicates if context has been changed with a "put" operation since the dirty flag
 	 * was last cleared. Note that the last time the flag was cleared might correspond to
-	 * creation of the context.
-	 * @return True if "put" operation has occurred since flag was last cleared
+	 * creation of the context. A context is only dirty if a new value is put or an old
+	 * one is removed.
+	 * @return True if a new value was put or an old one was removed since the last time
+	 * the flag was cleared
 	 */
 	public boolean isDirty() {
 		return this.dirty;

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2006-2024 the original author or authors.
+ * Copyright 2006-2025 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.
@@ -36,7 +36,7 @@
 /**
  * @author Lucas Ward
  * @author Mahmoud Ben Hassine
- *
+ * @author Seokmun Heo
  */
 class ExecutionContextTests {
 
@@ -94,11 +94,13 @@ void testNotDirtyWithDuplicate() {
 	}
 
 	@Test
-	void testNotDirtyWithRemoveMissing() {
+	void testDirtyWithRemoveMissing() {
 		context.putString("1", "test");
 		assertTrue(context.isDirty());
 		context.putString("1", null); // remove an item that was present
 		assertTrue(context.isDirty());
+
+		context.clearDirtyFlag();
 		context.putString("1", null); // remove a non-existent item
 		assertFalse(context.isDirty());
 	}
@@ -167,6 +169,15 @@ 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
 	 */