Conditional text elements cause crash when accessing their bounding box

[ygra]

E.g.:

<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN" "http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">
<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" version="1.1" viewBox="0 0 170 337" width="340" height="674">
<defs>
  <pattern id="p" patternUnits="userSpaceOnUse" width="170" height="24">
    <path fill="none" stroke="#a9a9a9" d='M113 0.5V25H169V0.5H0.5V25H113z'/>
  </pattern>
</defs>
<g transform='translate(.5,.5)'>
<rect fill='white' width='169' height='336'/>
<rect fill='#f2f2f2' width='169' height='24'/>
<g transform='translate(113,0)'>
<rect fill='#630000' width='56' height='24' y='24'/>
<rect fill='#770000' width='56' height='24' y='48'/>
<rect fill='#960000' width='56' height='24' y='72'/>
<rect fill='#a90000' width='56' height='24' y='96'/>
<rect fill='#cc0000' width='56' height='24' y='120'/>
<rect fill='#dd0000' width='56' height='24' y='144'/>
<rect fill='#ee0000' width='56' height='24' y='168'/>
<rect fill='#fa0103' width='56' height='24' y='192'/>
<rect fill='#ff9933' width='56' height='24' y='216'/>
<rect fill='#fdcc00' width='56' height='24' y='240'/>
<rect fill='#fdfe33' width='56' height='24' y='264'/>
<rect fill='#f2f88e' width='56' height='24' y='288'/>
<rect fill='#ffffff' width='56' height='24' y='312'/>
</g>
<g text-anchor='end' font-family='sans-serif' font-size='11px' transform='translate(70,0)'>

<switch text-anchor='middle' font-weight='bold' transform='translate(-70,0) translate(56.5,17)'>
<text systemLanguage='en'>Temperature (°C)</text>
<text systemLanguage='de'>Temperatur (°C)</text>
<text systemLanguage='ru' font-size='10px'>Температура (°C)</text>
<text>Temperature (°C)</text>
</switch>

<switch text-anchor='middle' font-weight='bold' transform='translate(-70,0) translate(141,17)'>
<text systemLanguage='en'>Color</text>
<text systemLanguage='de'>Farbe</text>
<text systemLanguage='ru' font-size='10px'>Цвет</text>
<text>Temperature (°C)</text>
</switch>

<text y='40'>550</text>
<text y='64'>630</text>
<text y='88'>680</text>
<text y='112'>740</text>
<text y='136'>770</text>
<text y='160'>800</text>
<text y='184'>850</text>
<text y='208'>900</text>
<text y='232'>950</text>
<text y='256'>1000</text>
<text y='280'>1100</text>
<text y='304'>1200</text>
<text y='328'>1300</text>
</g>
</g>
<rect fill='url(#p)' width='170' height='337'/>
</svg>

Within each switch only one element is actually rendered. In this case based on the system language. Perhaps we don't have to support switch properly (or just always use the fallback element), but at least we shouldn't crash on elements that simply aren't there because the browser does support switch properly).

[ygra]

Only in Firefox, apparently. In Chrome we don't crash.

[ygra]

Fixed by not calling getBBox() anymore, but instead getComputedTextLength() which returns 0 on Firefox for not rendered elements.

Doesn't quite work for switch yet, since the fallback element is always rendered, but that's another issue for later ...