ADDITIONAL SYSTEM INFORMATION :
java -version:
openjdk version "13-ea" 2019-09-17
OpenJDK Runtime Environment (build 13-ea+9)
OpenJDK 64-Bit Server VM (build 13-ea+9, mixed mode, sharing)

Windows 10 Home, Version 1803, Build 17134.590

A DESCRIPTION OF THE PROBLEM :
If the underlying WritableByteChannel errors when closing a sun.nio.cs.StreamEncoder (as returned by Channels.newWriter), then the channel is not closed.

This is somewhat similar to JDK-6266377, but is not dependent on using a BufferedWriter.

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
 - Create a subclass of WritableByteChannel which errors when calling .write, and prints some debugging message when closing.
 - Use Channels.newWriter to wrap an instance of this channel.
 - Write to the writer, and then close it.

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
The channel would be closed the exception thrown from .write() is propagated.
ACTUAL -
The channel is not closed, and the error from .write() is thrown.

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import java.io.IOException;
import java.io.Writer;
import java.nio.ByteBuffer;
import java.nio.channels.Channels;
import java.nio.channels.WritableByteChannel;
import java.nio.charset.StandardCharsets;

class Scratch
{
    public static void main( String[] args )
    {
        ErroringByteChannel channel = new ErroringByteChannel();
        try( Writer writer = Channels.newWriter( channel, StandardCharsets.UTF_8.newEncoder(), -1 ) )
        {
            writer.write( "Test" );
        }
        catch( IOException e )
        {
            e.printStackTrace();
        }
    }

    private static class ErroringByteChannel implements WritableByteChannel
    {
        private boolean open = true;

        @Override
        public int write( ByteBuffer src ) throws IOException
        {
            throw new IOException();
        }

        @Override
        public boolean isOpen()
        {
            return open;
        }

        @Override
        public void close()
        {
            open = false;
            System.out.println( "Closing" );
        }
    }
}

---------- END SOURCE ----------