[Proposal] Keep/add `xmlns` attribute for generated SVG images

[wxiaoguang]

Feature Description

Gitea's SVG files do not have the xmlns attribute. Without it, these SVG images couldn't be display correctly.

• Browsers (Safari/Chrome/Firefox) only display the XML content, but no the image
• VSCode shows 0 x 0 broken images
• macOS Finder show blank page

Then developers couldn't browse these images, they couldn't know what the images look like before rendering them as inline SVG in a page.

So it's better to keep/add the xmlns attribute for the generated SVG files.

https://stackoverflow.com/questions/18467982/are-svg-parameters-such-as-xmlns-and-version-needed

cc @silverwind

Screenshots

[silverwind]

Yes it would be welcome to add xmlns to SVGs before rendering. GitHub also recently did this change.

[silverwind]

Actually I misread. You are talking about SVG assets, I'm talking about user content SVG image rendering.

xmlns is optional for SVG embedded inside HTML. It's only necessary when a SVG is rendered as it's own document, which we don't do. Adding it into HTML rendering would blow up our HTML unnecessarily by a few kilobytes, GitHub also does not do this.

[wxiaoguang]

Yup, for rendering, they do not need the xmlns.

We can remove the attribute before rendering, how do you think?

[wxiaoguang]

The PR: Keep/add xmlns attribute for generated SVG images #23410

The output is still clear, and developers could understand/choose SVG images quickly.