Markdown: Too greedy italic punctuation

[RunDevelopment]

Information

• Language: Markdown
• Plugins: none

Description
The punctuation of italic text with * and _ will match any number of leading *s and _s.

Scratch and bold have similar issues.

Code snippet

*__foo__* or _**bar**_

---

I want to mention that this bug is trivial to fix using #1679.
Possible solution:

// Allow only one line break
pattern: /(^|[^\\])([*_])((?:(?:\r?\n|\r)(?!\r?\n|\r)|.)+?)(\2)/,
lookbehind: true,
greedy: true,
groups: {
	$2: 'punctuation',
	$4: 'punctuation',
}

Support for nested styles could be added with $3: Prism.languages.markdown.

[ghost]

Can confirm. The behaviour of PrismJS and GitHub markdown is the same. Both do not implement bold italics as expected:

# Chapter Title

A **bold** sample.

## Section Title

An _italicised_ sample.

### Subsection Title

A **_bold italicised_** sample.

When converted from Markdown to PDF (via pandoc and ConTeX), the output resembles:

PrismJS produces the following: