引用功能会剥离内容中的一些有用的 HTML 标签

[Canapin (Coin-coin le Canapin)]

Using the quote or copy quote button strips out some HTML tags that should be kept.

Reproduction steps:

1. Quote or copy quote this sentence:

   There are 10⁸⁰ atoms in the observable universe and the glucose molecule formula is ₆H₁₂O₆. this however won’t be stripped out.

2. The copied content in the composer will appear as:

   There are 1080 atoms in the observable universe and the glucose molecule formula is 6H12O6. this however won’t be stripped out.

The removed HTML tags are <sup> and <sub>. I suppose there are others I’m not aware of, which should also be kept.

It looks more like an oversight than a bug.

[Canapin (Coin-coin le Canapin)]

Here’s the current list of allowed HTML tags when converting the selected content to markdown: https://github.com/discourse/discourse/blob/85773eee21a476e89fcab89213a5b827a7fa6d8e/app/assets/javascripts/discourse/app/lib/to-markdown.js#L147

  static allowedTags() {
    return [
      "ins",
      "del",
      "small",
      "big",
      "kbd",
      "ruby",
      "rt",
      "rb",
      "rp",
      "mark",
    ];
  }

It could be expanded a bit. I don’t think allowing <sup> and <sub> would cause issues, but what do I know, I’m not a programmer.