SVG pattern inconsistency between chrome and firefox

Question

I have a gradient overlaying a solid color (red) specified as a pattern:

<svg width="480" height="480">
    <defs>

        <pattern width="1" height="1" x="0" y="0" id="pattern">
            <rect width="240" height="240" x="0" y="0" fill="rgba(255,0,0,1)"/>
            <rect width="240" height="240" x="0" y="0" fill="url(#gradient)"/>
        </pattern>

        <linearGradient id="gradient" x1="0" y1="1" x2="0" y2="0">
            <stop offset="0%" stop-color="rgb(0,0,0)" stop-opacity="1"/>
            <stop offset="100%" stop-color="rgb(0,0,0)" stop-opacity="0"/>
        </linearGradient>

    </defs>
    <path
      transform="matrix(1,0,0,1,200,200)"
      d="M0 0M 120 0 A 120 120 0 0 0 -120 0 A 120 120 0 0 0 120 0"
      fill="url(#pattern)"
    />
</svg>

Left: Firefox. Right: Chrome

The one on the right (Chrome) is correct.

Does anyone know how to make this work in Firefox?

See it live: http://jsbin.com/eyenoh/edit#html,live

Answer 1

I was able to get it working by using the object bounding box as coordinate system for the pattern content.

<pattern width="1" height="1" x="0" y="0" id="pattern" patternContentUnits="objectBoundingBox">
    <rect width="1" height="1" x="0" y="0" fill="rgba(255,0,0,1)"/>
    <rect width="1" height="1" x="0" y="0" fill="url(#gradient)"/>
</pattern>

See it here: http://jsbin.com/efesev/edit#html,live

I'll try to investigate further. Looks like a good candidate for a bug report.