Link to PDF file (or attach file here):
[pages4.pdf](https://github.com/mozilla/pdf.js/files/1128300/pages4.pdf)

Configuration:
- Web browser and its version: Firefox 54
- Operating system and its version: Win 10
- PDF.js version: 1.8.522
- Is an extension: no

What is the expected behavior? (add screenshot)
![chrome1-1 1](https://user-images.githubusercontent.com/146436/27918380-2f74512a-6245-11e7-8525-d0038fa6c2e8.jpg)
![chrome1-2 1](https://user-images.githubusercontent.com/146436/27918425-54f8e47e-6245-11e7-9bff-127f79ad0511.jpg)


What went wrong? (add screenshot)
![screenshot from 2017-07-06 12-10-30](https://user-images.githubusercontent.com/146436/27918442-5d57624e-6245-11e7-9436-5ba31cc8bd1a.png)
![screenshot from 2017-07-06 12-10-44](https://user-images.githubusercontent.com/146436/27918454-63b486da-6245-11e7-9eb5-c03aa5c40943.png)



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);
          break;
        case OPS.curveTo:
          x = args[j + 4];
          y = args[j + 5];
          ctx.bezierCurveTo(
            args[j],
            args[j + 1],
            args[j + 2],
            args[j + 3],
            x,
            y