Steps to reproduce (this PDF):
[page4.pdf](https://github.com/mozilla/pdf.js/files/5990272/page4.pdf)

````
npm install
node_modules/.bin/gulp dist-install
node examples/node/pdf2svg.js /tmp/page4.pdf
````

Error:
````
Error: Invalid SVG dimensions
    at unreachable (/tmp/pdf.js/build/dist/legacy/build/pdf.js:2086:9)
    at assert (/tmp/pdf.js/build/dist/legacy/build/pdf.js:2091:5)
    at DOMSVGFactory.create (/tmp/pdf.js/build/dist/legacy/build/pdf.js:640:24)
    at SVGGraphics._makeTilingPattern (/tmp/pdf.js/build/dist/legacy/build/pdf.js:24178:36)
    at SVGGraphics._makeColorN_Pattern (/tmp/pdf.js/build/dist/legacy/build/pdf.js:24127:23)
    at SVGGraphics.setFillColorN (/tmp/pdf.js/build/dist/legacy/build/pdf.js:24088:39)
    at SVGGraphics.executeOpTree (/tmp/pdf.js/build/dist/legacy/build/pdf.js:23634:22)
    at /tmp/pdf.js/build/dist/legacy/build/pdf.js:23508:18
    at process._tickCallback (internal/process/next_tick.js:68:7)
    at Function.Module.runMain (internal/modules/cjs/loader.js:834:11)
````
this.current.lineCap = LINE_CAP_STYLES[style];
    }
    setLineJoin(style) {
      this.current.lineJoin = LINE_JOIN_STYLES[style];
    }
    setMiterLimit(limit) {
      this.current.miterLimit = limit;
    }
    setStrokeAlpha(strokeAlpha) {
      this.current.strokeAlpha = strokeAlpha;
    }
    setStrokeRGBColor(r, g, b) {
      this.current.strokeColor = Util.makeHexColor(r, g, b);
    }
    setFillAlpha(fillAlpha) {
      this.current.fillAlpha = fillAlpha;
    }
    setFillRGBColor(r, g, b) {
      this.current.fillColor = Util.makeHexColor(r, g, b);
      this.current.tspan = this.svgFactory.createElement("svg:tspan");
      this.current.xcoords = [];
      this.current.ycoords = [];
    }
    setStrokeColorN(args) {
      this.current.strokeColor = this._makeColorN_Pattern(args);
    }
    setFillColorN(args) {