Serialization/Deserialization fails for large objects with ArrayIndexOutOfBoundsException

I have a custom serializer:

class CustomSerializerDesc implements Serializer<DescribeSObjectResult>
	{
		private final XStream xstream = new XStream();

		@Override
		public void serialize(final DataOutput2 out, final DescribeSObjectResult sObject) throws IOException
		{
			xstream.toXML(sObject, out);
		}

		@Override
		public DescribeSObjectResult deserialize(final DataInput2 input, final int available) throws IOException
		{
			final DataInputToStream input2 = new DataInput2.DataInputToStream(input);
			return (DescribeSObjectResult) xstream.fromXML(input2);
		}

	}

where the usage drops across

final DB db = DBMaker
				.fileDB(SalesforceOptions.cachePath.resolve("SalesforceObjects").toFile())
				.fileMmapEnable()
				.fileDeleteAfterClose()
				.cleanerHackEnable()
				.make();
		final CustomSerializerDesc customSerializer = new CustomSerializerDesc();
		final List<DescribeSObjectResult> finalDescs = db.indexTreeList("test", customSerializer).createOrOpen();

However, when iterating through the lists, it throws an exception
Exception in thread "main" with the root cause pointing here:

Caused by: java.lang.ArrayIndexOutOfBoundsException
	at java.lang.System.arraycopy(Native Method)
	at org.mapdb.DataInput2$ByteArray.readFully(DataInput2.java:28)
	at org.mapdb.DataInput2$DataInputToStream.read(DataInput2.java:242)
	at java.io.FilterInputStream.read(FilterInputStream.java:133)
	at java.io.PushbackInputStream.read(PushbackInputStream.java:186)
	at sun.nio.cs.StreamDecoder.readBytes(StreamDecoder.java:284)
	at sun.nio.cs.StreamDecoder.implRead(StreamDecoder.java:326)
	at sun.nio.cs.StreamDecoder.read(StreamDecoder.java:178)
	at java.io.InputStreamReader.read(InputStreamReader.java:184)

This doesn't happen to small objects. I tried a custom serializer with a different class that works fine. However, this is a large class and somehow fails. Does serialization/deserialization have any limits on the buffer size?

Start with DataInput2.java, especially ByteArray.readFully and DataInputToStream.read, then reproduce the failure using the custom serializer, file-backed DB, and large DescribeSObjectResult shown here. Determine whether large-object deserialization exceeds a buffer or exposes another read-boundary problem; done means iteration completes without ArrayIndexOutOfBoundsException for the large object.