CSS Minify Option Breaks inline SVG XML

[jvreeken]

Preconditions

1. Magento 2.1.1

Steps to reproduce

1. In your css, use an svg as an background image
2. Example:
   background:url('data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" id="Layer_1" viewBox="0 0 38 40"><style>.st0{fill:none;stroke:%23ffffff;stroke-width:2;stroke-linecap:round;stroke-miterlimit:10;}</style><circle cx="14.7" cy="14.7" r="13.7" class="st0"/><path d="M23.9 24.7L37 39" class="st0"/></svg>') no-repeat left center;
   (Note that Colors with hex values need # to be url encoded to %23 to not break firefox and safari)
3. Turn on css minify in the backend
4. deploy static content

Expected result

1. The svg xml should not be minified / should be minified and url encoded hash symbols for colors to work in all browsers
   background:url('data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" id="Layer_1" viewBox="0 0 38 40"><style>.st0{fill:none;stroke:%23ffffff;stroke-width:2;stroke-linecap:round;stroke-miterlimit:10;}</style><circle cx="14.7" cy="14.7" r="13.7" class="st0"/><path d="M23.9 24.7L37 39" class="st0"/></svg>') no-repeat left center;

Actual result

1. The svg xml is not properly parsed and breaks the image and does not display:
   Spaces are removed that should not be removed (marked in bold below)...

background:url('data:image/svg+xml;utf8,<svgxmlns="http://www.w3.org/2000/svg"id="Layer_1"viewBox="**003840**"><style>.st0{fill:none;stroke:%23ffffff;stroke-width:2;stroke-linecap:round;stroke-miterlimit:10;}</style><circlecx="14.7"cy="14.7"r="13.7"class="st0"/><pathd="**M23.924.7L3739**"class="st0"/></svg>') no-repeat left center;

There is a similar example here with other css minify libraries:
yui/yuicompressor#141

I'd like to be able to use inline svgs as background images to reduce http requests.
For now I've just changed them to use svg files in the meantime...

[magento-team]

Internal ticket to track issue progress: MAGETWO-67487

[magento-engcom-team]

@jvreeken, thank you for your report.
The issue is already fixed in 2.2.0

[Green2Matter]

Magento 2.4.3-p2 there's exactly same issue: svg (xml) included in custom css file as background is wrongly minified...