Inline HTML inside a block component loses its content (0.8) #505

Environment

• Operating System: Linux
• Node Version: v24.21.0
• Package Manager: pnpm@11.18.0
• Comark Version: 0.8.1
• Framework: None

Comark Version

v0.8.1

Reproduction

import { parseMarkdown } from "comark";

const { nodes } = await parseMarkdown("::foo\nNote <b>x</b> end\n::");
console.log(JSON.stringify(nodes));

The text inside <b> moves out of it. 0.7.0 (-) against 0.8.1 (+):

-[["foo",{},"Note ",["b",{"$":{"html":1,"block":0}},"x"]," end"]]
+[["foo",{},"Note x",["b",{"$":{"html":1,"block":0}}]," end"]]

Rendered with @comark/html:

-<div class="foo">Note <b>x</b> end</div>
+<div class="foo">Note x<b></b> end</div>

The same line outside a block is fine on both versions:

await parseMarkdown("Note <b>x</b> end");
// [["p",{},"Note ",["b",{"$":{"html":1,"block":0}},"x"]," end"]]

Description

Inside a :: block component, inline HTML loses its content. The text between the tags joins the text before it, and the element is left empty. The same line in a paragraph or a blockquote parses correctly. It happens with every inline tag I tried (b, kbd, sub, script).

It started in 0.8.0 with the token processor refactor (#401). In packages/comark/src/internal/parse/tree.ts, paragraph_open passes nestHtml = state.insideMarkdownContainer === 0 to processChildren. Inside a block component that's false, so the inline text isn't delivered into the open HTML element, while the element itself is still created.

Additional context

Found while moving comark-plugins to 0.8.1: inline HTML inside annotate's notes and inside tabs renders wrong.