Extra empty newlines causes arguments to be split up when they should be left intact as one

[rcjsuen]

The below Dockerfile is valid and builds without any problems save for the warning about the empty continuation line.

FROM alp\

ine

$ docker build .
Sending build context to Docker daemon  1.695MB
[WARNING]: Empty continuation line found in:
    FROM alpine
[WARNING]: Empty continuation lines will become errors in a future release.
Step 1/1 : FROM alpine
 ---> 3fd9065eaf02
Successfully built 3fd9065eaf02
[node1] (local) root@192.168.0.8 ~

We expect only one argument to FROM but the parser thinks there are two!

import { DockerfileParser, Label } from './main';

const content = "FROM alp\\\n\nine";

let dockerfile = DockerfileParser.parse(content);
console.log(dockerfile.getInstructions()[0].getArguments().length);

2