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)
````
} else {
        current.x += x * textHScale;
      }
      current.tspan.setAttributeNS(null, "font-family", current.fontFamily);
      current.tspan.setAttributeNS(
        null,
        "font-size",
        `${pf(current.fontSize)}px`
      );
      if (current.fontStyle !== SVG_DEFAULTS.fontStyle) {
        current.tspan.setAttributeNS(null, "font-style", current.fontStyle);
      }
      if (current.fontWeight !== SVG_DEFAULTS.fontWeight) {
        current.tspan.setAttributeNS(null, "font-weight", current.fontWeight);
      }
      const fillStrokeMode =
        current.textRenderingMode & TextRenderingMode.FILL_STROKE_MASK;
      if (
        fillStrokeMode === TextRenderingMode.FILL ||
        fillStrokeMode === TextRenderingMode.FILL_STROKE
      ) {
        if (current.fillColor !== SVG_DEFAULTS.fillColor) {
          current.tspan.setAttributeNS(null, "fill", current.fillColor);
        }
        if (current.fillAlpha < 1) {
          current.tspan.setAttributeNS(null, "fill-opacity", current.fillAlpha);
        }
      } else if (current.textRenderingMode === TextRenderingMode.ADD_TO_PATH) {