Fix test-failure on macOS with JDK versions < 20 (netty#12597)

Motivation:

Calling DatagramChannel.disconnect() on JDK versions < 20 with mapped ipv6 addresses throw an exception, we should workaround this bug.

Modifications:

Only try to call disconnect() when the DatagramChannel is not using NIO when using mapped ipv6 addresses

Result:

No more build failures on macOS

testsuite/src/main/java/io/netty/testsuite/transport/socket/DatagramUnicastIPv6MappedTest.java

@@ -15,7 +15,10 @@
  */
 package io.netty.testsuite.transport.socket;
 
+import io.netty.channel.socket.DatagramChannel;
+import io.netty.channel.socket.nio.NioDatagramChannel;
 import io.netty.util.NetUtil;
+import io.netty.util.internal.PlatformDependent;
 
 import java.net.InetAddress;
 import java.net.InetSocketAddress;
@@ -36,4 +39,13 @@ protected InetSocketAddress sendToAddress(InetSocketAddress serverAddress) {
         }
         return serverAddress;
     }
+
+    @Override
+    protected boolean disconnectMightFail(DatagramChannel channel) {
+        // See https://bugs.openjdk.org/browse/JDK-8285515
+        if (channel instanceof NioDatagramChannel && PlatformDependent.javaVersion() < 20) {
+            return true;
+        }
+        return super.disconnectMightFail(channel);
+    }
 }

testsuite/src/main/java/io/netty/testsuite/transport/socket/DatagramUnicastTest.java

@@ -24,6 +24,7 @@
 import io.netty.channel.ChannelHandlerContext;
 import io.netty.channel.ChannelOption;
 import io.netty.channel.SimpleChannelInboundHandler;
+import io.netty.channel.socket.DatagramChannel;
 import io.netty.util.NetUtil;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.TestInfo;
@@ -32,6 +33,7 @@
 import java.net.InetAddress;
 import java.net.InetSocketAddress;
 import java.net.SocketAddress;
+import java.net.SocketException;
 import java.nio.channels.NotYetConnectedException;
 import java.util.ArrayList;
 import java.util.List;
@@ -302,8 +304,17 @@ private void testSimpleSendWithConnect0(Bootstrap sb, Bootstrap cb, ByteBuf buf,
             assertNotNull(cc.remoteAddress());
 
             if (supportDisconnect()) {
-                // Test what happens when we call disconnect()
-                cc.disconnect().syncUninterruptibly();
+                try {
+                    // Test what happens when we call disconnect()
+                    cc.disconnect().syncUninterruptibly();
+                } catch (Throwable e) {
+                    if (e instanceof SocketException) {
+                        if (disconnectMightFail((DatagramChannel) cc)) {
+                            return;
+                        }
+                    }
+                    throw e;
+                }
                 assertFalse(isConnected(cc));
                 assertNotNull(cc.localAddress());
                 assertNull(cc.remoteAddress());
@@ -348,6 +359,10 @@ protected abstract Channel setupServerChannel(Bootstrap sb, byte[] bytes, Socket
 
     protected abstract boolean supportDisconnect();
 
+    protected boolean disconnectMightFail(DatagramChannel channel) {
+        return false;
+    }
+
     protected abstract ChannelFuture write(Channel cc, ByteBuf buf, SocketAddress remote, WrapType wrapType);
 
     protected static void closeChannel(Channel channel) throws Exception {