From d273919155cfef48d807b7f93430b52944e145f4 Mon Sep 17 00:00:00 2001
From: Greg Hogan <code@greghogan.com>
Date: Thu, 8 Sep 2016 10:35:39 -0400
Subject: [PATCH] [FLINK-4594] [core] Validate lower bound in
 MathUtils.checkedDownCast

---
 .../src/main/java/org/apache/flink/util/MathUtils.java      | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/flink-core/src/main/java/org/apache/flink/util/MathUtils.java b/flink-core/src/main/java/org/apache/flink/util/MathUtils.java
index 49056ccd80f96..074e8aea66f9c 100644
--- a/flink-core/src/main/java/org/apache/flink/util/MathUtils.java
+++ b/flink-core/src/main/java/org/apache/flink/util/MathUtils.java
@@ -80,12 +80,14 @@ public static int roundDownToPowerOf2(int value) {
 	 * 
 	 * @param value The value to be cast to an integer.
 	 * @return The given value as an integer.
+	 * @see Math#toIntExact(long)
 	 */
 	public static int checkedDownCast(long value) {
-		if (value > Integer.MAX_VALUE) {
+		int downCast = (int) value;
+		if (downCast != value) {
 			throw new IllegalArgumentException("Cannot downcast long value " + value + " to integer.");
 		}
-		return (int) value;
+		return downCast;
 	}
 
 	/**