Attach (recommended) or Link to PDF file here:
[Test file.pdf](https://github.com/mozilla/pdf.js/files/4656226/Test.file.pdf)

Configuration:
- Web browser and its version: Chrome Version 81.0.4044.138 (Official Build) (64-bit)
- Operating system and its version: Windows 10
- PDF.js version: latest
- Is a browser extension: no

Steps to reproduce the problem:
1. Open [https://mozilla.github.io/pdf.js/web/viewer.html](https://mozilla.github.io/pdf.js/web/viewer.html)
2. Load the provided .pdf file

What is the expected behavior? (add screenshot)
![image](https://user-images.githubusercontent.com/5569382/82438616-02c3fe80-9aa2-11ea-9003-b75ea1e7aac6.png)

What went wrong? (add screenshot)
![image](https://user-images.githubusercontent.com/5569382/82438640-09527600-9aa2-11ea-810b-071da7e37896.png)


let x = current.x,
        y = current.y;
      for (let i = 0, j = 0, ii = ops.length; i < ii; i++) {
        switch (ops[i] | 0) {
          case OPS.rectangle:
            x = args[j++];
            y = args[j++];
            const width = args[j++];
            const height = args[j++];
            const xw = x + width;
            const yh = y + height;
            ctx.moveTo(x, y);
            if (width === 0 || height === 0) {
              ctx.lineTo(xw, yh);
            } else {
              ctx.lineTo(xw, y);
              ctx.lineTo(xw, yh);
              ctx.lineTo(x, yh);
            }
            ctx.closePath();
            break;
          case OPS.moveTo:
            x = args[j++];
            y = args[j++];
            ctx.moveTo(x, y);
            break;
          case OPS.lineTo:
            x = args[j++];
            y = args[j++];
            ctx.lineTo(x, y);