Empty XML comment in SVG panics the minifier (500)
Author: diegoatpitchCreated Jul 13, 2026Updated Jul 13, 2026
Version 4.0.11
Processing any SVG that contains an empty XML comment (<!---->) causes the SVG minifier to panic and return to the client as HTTP 500.
Minimal reproduction
<svg xmlns="http://www.w3.org/2000/svg" width="10" height="10"><!----><rect width="10" height="10"/></svg>Replacing <!----> with any non-empty body (<!--x-->) renders fine.
Stack trace (from prod logs)
runtime error: index out of range [0] with length 0
/app/processing/svg/minify/minify.go:146 (*minifier).cleanupWalk.func1.(*minifier).cleanupWalk.1
/app/xmlparser/node.go:22 (*Node).FilterChildren.func1
/usr/local/go/src/slices/slices.go:109 slices.IndexFunc[...]
/usr/local/go/src/slices/slices.go:240 slices.DeleteFunc[...]
/app/xmlparser/node.go:21 (*Node).FilterChildren
/app/processing/svg/minify/minify.go:138 (*minifier).cleanupWalk.func1
/app/processing/svg/minify/minify.go:168 (*minifier).cleanupWalk.func1Source: imgproxy/imgproxy