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)
````
current.tspan.setAttributeNS(null, "fill", "transparent");
      } else {
        current.tspan.setAttributeNS(null, "fill", "none");
      }
      if (
        fillStrokeMode === TextRenderingMode.STROKE ||
        fillStrokeMode === TextRenderingMode.FILL_STROKE
      ) {
        const lineWidthScale = 1 / (current.textMatrixScale || 1);
        this._setStrokeAttributes(current.tspan, lineWidthScale);
      }
      
      
      
      let textMatrix = current.textMatrix;
      if (current.textRise !== 0) {
        textMatrix = textMatrix.slice();
        textMatrix[5] += current.textRise;
      }
      current.txtElement.setAttributeNS(
        null,
        "transform",
        `${pm(textMatrix)} scale(${pf(textHScale)}, -1)`
      );
      current.txtElement.setAttributeNS(XML_NS, "xml:space", "preserve");
      current.txtElement.appendChild(current.tspan);
      current.txtgrp.appendChild(current.txtElement);
      this._ensureTransformGroup().appendChild(current.txtElement);
    }
    setLeadingMoveText(x, y) {