Here's my (truncated) example SVG image (made with Highcharts, http://www.highcharts.com/ ) - when I render that onto a canvas (with canvg (https://github.com/gabelerner/canvg and code adapted from here: https://stackoverflow.com/a/8997520/2067690) all text in the resulting PNG is duplicated, meaning that it's output double, one piece of text immediately followed by the same text once again. How can I ensure it appears once only?
<svg height="400" width="1170" version="1.1" xmlns="http://www.w3.org/1999/svg">
<text zIndex="8" text-anchor="end" style="font-family:"Lucida Grande", "Lucida Sans Unicode", Verdana, Arial, Helvetica, sans-serif;font-size:9px;cursor:pointer;color:#909090;fill:#909090;" y="22" x="220">
<tspan x="220">Highcharts.com</tspan>
</text>
</svg>
After much deleting parts of my example SVG image, to find when the error would go away, I found that it's the tspan tags - once I leave them out, canvg will display text only once as intended.