Coverage remained the same at 97.283% when pulling 84c4c66 on seaoak:bugfix/backtick_code_block_on_blockquote_always_terminates_the_blockquote_block into 6b329e9 on hexojs:master.

Using your example:

> This is a code-block
> 
> ```json
> {
>   "test": 123
> }
> ```
>
> This is a following paragraph

a note for anyone's new to Markdown is that, the "following paragraph" is displayed immediately after the codeblock (no newline), regardless of how many > are there. another example,

> This is a code-block
> 
> ```json
> {
>   "test": 123
> }
> ```
>
>
>
> This is a following paragraph

The above wouldn't have new lines either.

This is not a limitation of this PR (nor #3765), the behavior is rather expected for Markdown; I figure it could be rather unexpected for those who are new to Markdown.

PS:

>
>
> no new lines
>
>

would be displayed as:

no new lines

not

no new lines

@curbengh Thank you for review and advice!
Your advice is very helpful in making new patch for a bug of PR #3765