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)
````
const width = imgData.width;
      const height = imgData.height;
      const imgSrc = convertImgDataToPng(imgData, this.forceDataSchema, !!mask);
      const cliprect = this.svgFactory.createElement("svg:rect");
      cliprect.setAttributeNS(null, "x", "0");
      cliprect.setAttributeNS(null, "y", "0");
      cliprect.setAttributeNS(null, "width", pf(width));
      cliprect.setAttributeNS(null, "height", pf(height));
      this.current.element = cliprect;
      this.clip("nonzero");
      const imgEl = this.svgFactory.createElement("svg:image");
      imgEl.setAttributeNS(XLINK_NS, "xlink:href", imgSrc);
      imgEl.setAttributeNS(null, "x", "0");
      imgEl.setAttributeNS(null, "y", pf(-height));
      imgEl.setAttributeNS(null, "width", pf(width) + "px");
      imgEl.setAttributeNS(null, "height", pf(height) + "px");
      imgEl.setAttributeNS(
        null,
        "transform",
        `scale(${pf(1 / width)} ${pf(-1 / height)})`
      );
      if (mask) {
        mask.appendChild(imgEl);
      } else {
        this._ensureTransformGroup().appendChild(imgEl);
      }
    }
    paintImageMaskXObject(imgData) {