From 87b173818a69f8d7e032bdd814b54661de60e9c1 Mon Sep 17 00:00:00 2001
From: David Ho <70000000+davidh44@users.noreply.github.com>
Date: Wed, 9 Aug 2023 12:11:25 -0700
Subject: [PATCH] Fix immutableCopyOf bug (#4266)

* Set limit when cloning ByteBuffer

* Add changelog
---
 .../next-release/bugfix-AWSSDKforJavav2-5ae7899.json  |  6 ++++++
 .../software/amazon/awssdk/utils/BinaryUtils.java     |  4 ++--
 .../software/amazon/awssdk/utils/BinaryUtilsTest.java | 11 +++++++++++
 3 files changed, 19 insertions(+), 2 deletions(-)
 create mode 100644 .changes/next-release/bugfix-AWSSDKforJavav2-5ae7899.json

diff --git a/.changes/next-release/bugfix-AWSSDKforJavav2-5ae7899.json b/.changes/next-release/bugfix-AWSSDKforJavav2-5ae7899.json
new file mode 100644
index 000000000000..45f374c0377c
--- /dev/null
+++ b/.changes/next-release/bugfix-AWSSDKforJavav2-5ae7899.json
@@ -0,0 +1,6 @@
+{
+    "category": "AWS SDK for Java v2", 
+    "contributor": "", 
+    "type": "bugfix", 
+    "description": "Fixed bug where limit was not copied over when cloning ByteBuffer using immutableCopyOf()"
+}
diff --git a/utils/src/main/java/software/amazon/awssdk/utils/BinaryUtils.java b/utils/src/main/java/software/amazon/awssdk/utils/BinaryUtils.java
index 192ea7cead9b..e8d9271f3b65 100644
--- a/utils/src/main/java/software/amazon/awssdk/utils/BinaryUtils.java
+++ b/utils/src/main/java/software/amazon/awssdk/utils/BinaryUtils.java
@@ -133,12 +133,12 @@ public static ByteBuffer immutableCopyOf(ByteBuffer bb) {
         if (bb == null) {
             return null;
         }
-        int sourceBufferPosition = bb.position();
         ByteBuffer readOnlyCopy = bb.asReadOnlyBuffer();
         readOnlyCopy.rewind();
         ByteBuffer cloned = ByteBuffer.allocate(readOnlyCopy.capacity())
                                       .put(readOnlyCopy);
-        cloned.position(sourceBufferPosition);
+        cloned.position(bb.position());
+        cloned.limit(bb.limit());
         return cloned.asReadOnlyBuffer();
     }
 
diff --git a/utils/src/test/java/software/amazon/awssdk/utils/BinaryUtilsTest.java b/utils/src/test/java/software/amazon/awssdk/utils/BinaryUtilsTest.java
index 4e416ea9e3b6..b1287e2990ec 100644
--- a/utils/src/test/java/software/amazon/awssdk/utils/BinaryUtilsTest.java
+++ b/utils/src/test/java/software/amazon/awssdk/utils/BinaryUtilsTest.java
@@ -226,6 +226,17 @@ public void testImmutableCopyOfByteBuffer() {
         assertArrayEquals(bytesInSourceAfterCopy, fromSource);
     }
 
+    @Test
+    public void immutableCopyOf_retainsOriginalLimit() {
+        ByteBuffer sourceBuffer = ByteBuffer.allocate(10);
+        byte[] bytes = {1, 2, 3, 4};
+        sourceBuffer.put(bytes);
+        sourceBuffer.rewind();
+        sourceBuffer.limit(bytes.length);
+        ByteBuffer copy = BinaryUtils.immutableCopyOf(sourceBuffer);
+        assertThat(copy.limit()).isEqualTo(sourceBuffer.limit());
+    }
+
     @Test
     public void testImmutableCopyOfByteBuffer_nullBuffer() {
         assertNull(BinaryUtils.immutableCopyOf(null));