I have already asked a question about it some time ago in “How to”.
Maybe it doesn’t qualify as a bug, but as a “feature”. But this feature makes the option of using SVG icons unusable in certain contexts: when the SVG has rectangles or other shapes with defined dimensions. I don’t see a way to size them (without editing the files), because they are rendered as inline SVG. Reducing the width/height hides parts of the SVG.
Examples of SVGs that are currently unusable as icons:
I guess the solution is to output them as files <img src='/example.svg'> and not inline.
This will also allow to cache the files.