PDF with masks not rendered well on cairo backend
I have a file (generated by Chromium v97 printing a SVG file to PDF) that contains a masked object. This is an ellipse that masks a background rectangle: mask.pdf.
If I render it with cairo backend, the mask is not working and I see the whole rectangle. But with splash backend the render is ok. Here are the commands I used to generate the images:
pdftocairo -png -f 1 -l 1 mask.pdf -o cairo-output pdftoppm -png -f 1 -l 1 mask.pdf -o splash-output