CronSequenceGenerator prevents stack overflow in case of inverted range

Issue: SPR-14462
(cherry picked from commit da59b4d)

spring-context/src/main/java/org/springframework/scheduling/support/CronSequenceGenerator.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2015 the original author or authors.
+ * Copyright 2002-2016 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.
@@ -379,6 +379,10 @@ public class CronSequenceGenerator {
 			throw new IllegalArgumentException("Range less than minimum (" + min + "): '" +
 					field + "' in expression \"" + this.expression + "\"");
 		}
+		if (result[0] > result[1]) {
+			throw new IllegalArgumentException("Invalid inverted range: '" + field +
+					"' in expression \"" + this.expression + "\"");
+		}
 		return result;
 	}
 

spring-context/src/test/java/org/springframework/scheduling/support/CronSequenceGeneratorTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2015 the original author or authors.
+ * Copyright 2002-2016 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.
@@ -29,31 +29,51 @@ import static org.junit.Assert.*;
 public class CronSequenceGeneratorTests {
 
 	@Test
-	public void testAt50Seconds() {
+	public void at50Seconds() {
 		assertEquals(new Date(2012, 6, 2, 1, 0),
 				new CronSequenceGenerator("*/15 * 1-4 * * *").next(new Date(2012, 6, 1, 9, 53, 50)));
 	}
 
 	@Test
-	public void testAt0Seconds() {
+	public void at0Seconds() {
 		assertEquals(new Date(2012, 6, 2, 1, 0),
 				new CronSequenceGenerator("*/15 * 1-4 * * *").next(new Date(2012, 6, 1, 9, 53)));
 	}
 
 	@Test
-	public void testAt0Minutes() {
+	public void at0Minutes() {
 		assertEquals(new Date(2012, 6, 2, 1, 0),
 				new CronSequenceGenerator("0 */2 1-4 * * *").next(new Date(2012, 6, 1, 9, 0)));
 	}
 
 	@Test(expected = IllegalArgumentException.class)
-	public void testWith0Increment() {
+	public void with0Increment() {
 		new CronSequenceGenerator("*/0 * * * * *").next(new Date(2012, 6, 1, 9, 0));
 	}
 
 	@Test(expected = IllegalArgumentException.class)
-	public void testWithNegativeIncrement() {
+	public void withNegativeIncrement() {
 		new CronSequenceGenerator("*/-1 * * * * *").next(new Date(2012, 6, 1, 9, 0));
 	}
 
+	@Test(expected = IllegalArgumentException.class)
+	public void withInvertedMinuteRange() {
+		new CronSequenceGenerator("* 6-5 * * * *").next(new Date(2012, 6, 1, 9, 0));
+	}
+
+	@Test(expected = IllegalArgumentException.class)
+	public void withInvertedHourRange() {
+		new CronSequenceGenerator("* * 6-5 * * *").next(new Date(2012, 6, 1, 9, 0));
+	}
+
+	@Test
+	public void withSameMinuteRange() {
+		new CronSequenceGenerator("* 6-6 * * * *").next(new Date(2012, 6, 1, 9, 0));
+	}
+
+	@Test
+	public void withSameHourRange() {
+		new CronSequenceGenerator("* * 6-6 * * *").next(new Date(2012, 6, 1, 9, 0));
+	}
+
 }