From 8f5207e6ca28e58f4bde331a7e74034c83703a71 Mon Sep 17 00:00:00 2001
From: Ludovic Orban <lorban@bitronix.be>
Date: Wed, 10 Jul 2024 16:52:51 +0200
Subject: [PATCH] Fix broken client tls negotiation (#11999)

#11965 make EMPTY_BUFFER not read-only anymore

Signed-off-by: Ludovic Orban <lorban@bitronix.be>
---
 .../jetty-io/src/main/java/org/eclipse/jetty/io/Content.java | 2 +-
 .../org/eclipse/jetty/quic/common/QuicStreamEndPoint.java    | 3 +--
 .../eclipse/jetty/server/NegotiatingServerConnection.java    | 5 ++---
 .../src/main/java/org/eclipse/jetty/util/BufferUtil.java     | 2 +-
 4 files changed, 5 insertions(+), 7 deletions(-)

diff --git a/jetty-core/jetty-io/src/main/java/org/eclipse/jetty/io/Content.java b/jetty-core/jetty-io/src/main/java/org/eclipse/jetty/io/Content.java
index e491e3e34bc..d622481f5ed 100644
--- a/jetty-core/jetty-io/src/main/java/org/eclipse/jetty/io/Content.java
+++ b/jetty-core/jetty-io/src/main/java/org/eclipse/jetty/io/Content.java
@@ -1024,7 +1024,7 @@ public class Content
          */
         default Chunk asReadOnly()
         {
-            if (getByteBuffer().isReadOnly())
+            if (!getByteBuffer().hasRemaining() || getByteBuffer().isReadOnly())
                 return this;
             if (canRetain())
                 return asChunk(getByteBuffer().asReadOnlyBuffer(), isLast(), this);
diff --git a/jetty-core/jetty-quic/jetty-quic-common/src/main/java/org/eclipse/jetty/quic/common/QuicStreamEndPoint.java b/jetty-core/jetty-quic/jetty-quic-common/src/main/java/org/eclipse/jetty/quic/common/QuicStreamEndPoint.java
index 227af953034..a86d7cd011c 100644
--- a/jetty-core/jetty-quic/jetty-quic-common/src/main/java/org/eclipse/jetty/quic/common/QuicStreamEndPoint.java
+++ b/jetty-core/jetty-quic/jetty-quic-common/src/main/java/org/eclipse/jetty/quic/common/QuicStreamEndPoint.java
@@ -42,7 +42,6 @@ public class QuicStreamEndPoint extends AbstractEndPoint
 {
     private static final Logger LOG = LoggerFactory.getLogger(QuicStreamEndPoint.class);
     private static final ByteBuffer LAST_FLAG = ByteBuffer.allocate(0);
-    private static final ByteBuffer EMPTY_WRITABLE_BUFFER = ByteBuffer.allocate(0);
 
     private final QuicSession session;
     private final long streamId;
@@ -272,7 +271,7 @@ public class QuicStreamEndPoint extends AbstractEndPoint
                 // Check if the stream was finished normally.
                 try
                 {
-                    fill(EMPTY_WRITABLE_BUFFER);
+                    fill(BufferUtil.EMPTY_BUFFER);
                 }
                 catch (EOFException x)
                 {
diff --git a/jetty-core/jetty-server/src/main/java/org/eclipse/jetty/server/NegotiatingServerConnection.java b/jetty-core/jetty-server/src/main/java/org/eclipse/jetty/server/NegotiatingServerConnection.java
index 038e02d48c3..59b1f6eb981 100644
--- a/jetty-core/jetty-server/src/main/java/org/eclipse/jetty/server/NegotiatingServerConnection.java
+++ b/jetty-core/jetty-server/src/main/java/org/eclipse/jetty/server/NegotiatingServerConnection.java
@@ -14,7 +14,6 @@
 package org.eclipse.jetty.server;
 
 import java.io.IOException;
-import java.nio.ByteBuffer;
 import java.util.List;
 import javax.net.ssl.SSLEngine;
 import javax.net.ssl.SSLEngineResult;
@@ -22,13 +21,13 @@ import javax.net.ssl.SSLEngineResult;
 import org.eclipse.jetty.io.AbstractConnection;
 import org.eclipse.jetty.io.Connection;
 import org.eclipse.jetty.io.EndPoint;
+import org.eclipse.jetty.util.BufferUtil;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 public abstract class NegotiatingServerConnection extends AbstractConnection
 {
     private static final Logger LOG = LoggerFactory.getLogger(NegotiatingServerConnection.class);
-    private static final ByteBuffer EMPTY_WRITABLE_BUFFER = ByteBuffer.allocate(0);
 
     public interface CipherDiscriminator
     {
@@ -145,7 +144,7 @@ public abstract class NegotiatingServerConnection extends AbstractConnection
     {
         try
         {
-            return getEndPoint().fill(EMPTY_WRITABLE_BUFFER);
+            return getEndPoint().fill(BufferUtil.EMPTY_BUFFER);
         }
         catch (IOException x)
         {
diff --git a/jetty-core/jetty-util/src/main/java/org/eclipse/jetty/util/BufferUtil.java b/jetty-core/jetty-util/src/main/java/org/eclipse/jetty/util/BufferUtil.java
index 82d39988bcd..39d22fb451e 100644
--- a/jetty-core/jetty-util/src/main/java/org/eclipse/jetty/util/BufferUtil.java
+++ b/jetty-core/jetty-util/src/main/java/org/eclipse/jetty/util/BufferUtil.java
@@ -107,7 +107,7 @@ public class BufferUtil
         };
 
     public static final byte[] EMPTY_BYTES = new byte[0];
-    public static final ByteBuffer EMPTY_BUFFER = ByteBuffer.wrap(EMPTY_BYTES).asReadOnlyBuffer();
+    public static final ByteBuffer EMPTY_BUFFER = ByteBuffer.wrap(EMPTY_BYTES);
 
     /**
      * Allocate ByteBuffer in flush mode.