CSHARP-717: Fix regression where reading from a socket that has been closed by the server is now hanging instead of throwing an EndOfStreamException.

Author: rstam

MongoDB.Bson/IO/ByteArrayBuffer.cs

@@ -275,6 +275,10 @@ public void LoadFrom(Stream stream, int count)
             while (count > 0)
             {
                 var bytesRead = stream.Read(_bytes, _sliceOffset + position, count);
+                if (bytesRead == 0)
+                {
+                    throw new EndOfStreamException();
+                }
                 position += bytesRead;
                 count -= bytesRead;
             }

MongoDB.Bson/IO/ByteBufferFactory.cs

@@ -78,6 +78,10 @@ public static IByteBuffer LoadFrom(Stream stream)
             while (count > 0)
             {
                 var bytesRead = stream.Read(lengthBytes, offset, count);
+                if (bytesRead == 0)
+                {
+                    throw new EndOfStreamException();
+                }
                 offset += bytesRead;
                 count -= bytesRead;
             }

MongoDB.Bson/IO/MultiChunkBuffer.cs

@@ -351,6 +351,10 @@ public void LoadFrom(Stream stream, int count)
                 var chunkRemaining = _chunkSize - chunkOffset;
                 var bytesToRead = (count <= chunkRemaining) ? count : chunkRemaining;
                 var bytesRead = stream.Read(_chunks[chunkIndex].Bytes, chunkOffset, bytesToRead);
+                if (bytesRead == 0)
+                {
+                    throw new EndOfStreamException();
+                }
                 position += bytesRead;
                 count -= bytesRead;
             }