Italics with underscores (e.g. _a_) don't render correctly with short strings (1 and 2 chars)

[kaelig]

Note: could be a duplicate of #1178 (the following issue may be more detailed though)

Marked version: 0.3.19

Markdown flavor: not sure

What pain point are you perceiving?

Short strings in italics don't render properly:

_a_

_ab_

See https://marked.js.org/demo/?text=Short%20strings%20in%20italics%20don%27t%20render%0A%0A_a_%0A%0A_ab_%0A%0AAll%20of%20these%20do%20render%20properly%3A%0A%0A*%20_abc_%0A*%20*a*%0A*%20*ab*%0A*%20*abc*%0A*%20__a__%0A*%20__ab__%0A*%20__abc__%0A*%20**a**%0A*%20**ab**%0A*%20**abc**%0A

What solution are you suggesting?

n/a

Expectation

<p><em>a</em></p>
<p><em>ab</em></p>

Result

<p>_a_</p>
<p>_ab_</p>

What was attempted

The workaround is to use * instead of _ to wrap italics. Unfortunately, formatters like Prettier enforces _ so you end up with having to do this (works in Prettier 1.12+):

<!-- prettier-ignore-start -->

_a_

_ab_

<!-- prettier-ignore-end -->

Or this if you're using prettier < 1.12

<i>a<i>

<i>ab</i>

[UziTech]

duplicate of #1178

should be fixed by #1181