Attach (recommended) or Link to PDF file here: https://www.recom-power.com/pdf/Powerline-AC-DC/RAC05-K.pdf

Configuration:
- Web browser and its version: Firefox 56.0 (64-bit)
- Operating system and its version: Windows 10 with OS Build 15063.632
- PDF.js version: ?
- Is an extension: Built-in

Steps to reproduce the problem:
1. Open Page

What is the expected behavior? To properly render the first page. 
![image](https://user-images.githubusercontent.com/1151969/31415345-b1504022-add7-11e7-855b-8030a308f7a2.png)

What went wrong? Renders poorly.
![image](https://user-images.githubusercontent.com/1151969/31415363-d8842096-add7-11e7-818d-728c1102891b.png)

Link to a viewer (if hosted on a site other than mozilla.github.io/pdf.js or as Firefox/Chrome extension): ?

this.ctx.closePath();
  }
  stroke(consumePath) {
    consumePath = typeof consumePath !== "undefined" ? consumePath : true;
    const ctx = this.ctx;
    const strokeColor = this.current.strokeColor;
    
    
    ctx.globalAlpha = this.current.strokeAlpha;
    if (this.contentVisible) {
      if (typeof strokeColor === "object" && strokeColor?.getPattern) {
        const lineWidth = this.getSinglePixelWidth();
        ctx.save();
        ctx.strokeStyle = strokeColor.getPattern(
          ctx,
          this,
          ctx.mozCurrentTransformInverse
        );
        
        ctx.lineWidth = Math.max(lineWidth, this.current.lineWidth);