as far as i remember this regex is coming from https://github.com/sveltejs/svelte/blob/9926347ad9dbdd0f3324d5538e25dcb7f5e442f8/packages/svelte/src/compiler/preprocess/index.js#L257 and the part you removed here is used to consume comments to avoid processing style blocks inside comments.

do you have a reproduction where a commented style is matched and processed by this? kind of reluctant to diverge from sveltes regex here (ultimately i'd love to get rid of it entirely, it is much too complex)

I pushed a fixup commit 69a2e0b that would preserver the regex, and here is a demo of the issue https://github.com/maxlath/vite-plugin-svelte-demo/

Thank you for working on this! to be able to release it we have to add a changeset. you can do that by running pnpm changeset and following the prompts. (select vite-plugin-svelte, patch and add a short description)

I ran pnpm changeset, squashed the fixup commits, and force pushed

Thanks, i'm in the middle of preparing 6.0.0, so this might go out after as 6.0.1 to not derail the already generated changelogs etc.