[Bug report] reloading markdown language will add wrap hook multiple times

Information:

• Prism version: 1.23.0
• Plugins: 'none'
• Environment: Node

Description

The reload logic is described here:

https://github.com/PrismJS/prism/blob/4e7b2a82d733fc705bc4a50192fb1bbe552bc687/dependencies.js#L383-L388

So the prism-markdown is possible to be reloaded multiple times, and the wrap hook will be added multiple times, too:

https://github.com/PrismJS/prism/blob/4e7b2a82d733fc705bc4a50192fb1bbe552bc687/components/prism-markdown.js#L320

For example:

1. Load markdown and javascript
2. Load jsdoc
   • jsdoc modifies javascript
   • javascript modifies markup
   • markup is depended by markdown
3. So javascript, markup and markdown will also be reloaded

Then, syntax highlighting inside markdown code block will be triggered multiple times.

Example

1. I tried to highlight markdown code:

2. The wrap hooks are:

3. Then the highlighted code:

Start with the reload logic in dependencies.js at the linked lines, then inspect the wrap hook registration in components/prism-markdown.js. Reproduce the markdown, javascript, and jsdoc reload sequence described in the issue; done means reloading dependencies does not register duplicate hooks or trigger repeated highlighting.