Parsing error when parsing nested bold+ital

[ShadiestGoat]

I want to parse the following text: **bold *ital***, expecting bold ital, but I'm getting bold *ital*.

This is caused by close the strong tag on the first instance of 2 *s, even though there is an open ital tag *.

what its being parsed as now:

[
	{
		"content": "bold *ital",
		"type": "bold"
	},
	{
		"content": "*",
		"type": "text"
	}
]

what it should be parsed as:

[
	{
		"type": "bold",
                "children": [
	           {
		     "content": "bold ",
		     "type": "text"
	           },
	           {
		     "content": "ital",
		     "type": "ital"
	           }
                ]
	}
]

[miekg]

the above is also what babelmark thinks https://babelmark.github.io/?text=**bold+*ital***

[vnykmshr]

helperDoubleEmphasis consumes *** as **, leaving the inner *ital without a closer. Fix shifts the content boundary when the last * in content is an unmatched opener. Fix with tests in PR #355.