<svg xmlns="http://www.w3.org/2000/svg">
<defs>
<clipPath id="clip1" clipPathUnits="objectBoundingBox">
<circle cx="0" cy="0" r="0.5" />
<circle cx="0" cy="1" r="0.5" />
</clipPath>
<clipPath id="clip2" clipPathUnits="objectBoundingBox">
<circle cx="1" cy="0" r="0.5" />
<circle cx="1" cy="1" r="0.5" />
</clipPath>
<clipPath id="clip" clipPathUnits="objectBoundingBox">
<rect x="0" y="0" width="1" height="1" clip-path="url(#clip1)"/>
<rect x="0" y="0" width="1" height="1" clip-path="url(#clip2)"/>
</clipPath>
<mask id="mask1a" x="0" y="0" width="1" height="1" maskContentUnits="objectBoundingBox">
<rect x="0" y="0" width="1" height="1" fill="white"/>
<rect x="0" y="0" width="1" height="1" fill="black" clip-path="url(#clip1)" />
</mask>
<mask id="mask1b" x="0" y="0" width="1" height="1" maskContentUnits="objectBoundingBox">
<rect x="0" y="0" width="1" height="1" fill="white"/>
<rect x="0" y="0" width="1" height="1" fill="black" clip-path="url(#clip2)" />
</mask>
<mask id="mask2" x="0" y="0" width="1" height="1" maskContentUnits="objectBoundingBox">
<rect x="0" y="0" width="1" height="1" fill="white" mask="url(#mask1a)"/>
</mask>
<mask id="mask3" x="0" y="0" width="1" height="1" maskContentUnits="objectBoundingBox">
<rect x="0" y="0" width="1" height="1" fill="white" mask="url(#mask1b)"/>
</mask>
</defs>
<!-- The mask on the <g> causes nothing to be renderer with Opera, clearly a bug -->
<g mask="url(#mask1a)">
<circle cx="50" cy="50" r="50" fill="black" mask="url(#mask1b)"/>
</g>
<!-- The mask on the <g> causes nothing to be renderer with Opera, clearly a bug -->
<g mask="url(#mask3)">
<circle cx="150" cy="150" r="50" fill="black" mask="url(#mask2)"/>
</g>
<text x="250" y="250" text-anchor="middle">The left shape should still be visible after panning<tspan x="250" dy="25">And the right shape shouldn't look distorted</tspan></text>
<script>
var translate = document.getElementsByTagName('svg')[0].currentTranslate;
translate.x = -75;
</script>
</svg>