Don't pass through zero-length requests

src/net/stream.c

 		return;
 	}
 
+	/* Ignore zero-length blocks */
+	if ( len == 0 )
+		return;
+
 	/* Hand off to application */
 	if ( app->op->acked )
 		app->op->acked ( app, len );
 		return;
 	}
 
+	/* Ignore zero-length blocks */
+	if ( len == 0 )
+		return;
+
 	/* Hand off to application */
 	if ( app->op->newdata )
 		app->op->newdata ( app, data, len );
 		return -ENOTCONN;
 	}
 
+	/* Ignore zero-length blocks */
+	if ( len == 0 )
+		return 0;
+
 	/* Hand off to connection */
 	if ( ! conn->op->send )
 		return -ENOTSUP;