There is something a bit odd with PL/SQL (or SQL - I'm not sure whether PL/SQL is actually supported. It seems to be sadly unpopular with syntax highlighting plugins.)

A quoted SQL statement seems to defeat the quoting, but only when an earlier line ends with a semicolon.

``` lang-sql
select blah into blahblah from blahblahblah;  -- Semicolon here seems to do it

xxx := 'select select';

Quoting is now reversed.
```

Screenshot for posterity:

![highlight-js glitch with SQL](https://i.sstatic.net/wLDTK.png)

The actual post where this came up is here: https://stackoverflow.com/a/64183788/230471