Reproduction steps:
* In a comment enter the content of this paste : P2029
* See the preview
* Notice that the `foobar10` is fully visible while only 2 lines were expected to be seen
Use case:
When deploying, a bot post a message in conpherence. Some part of the message are quite rarely used, so we would like to have it hidden by default.
Maybe the solution is something different from this bug.
Versions:
```
phabricator 71de5f2da2551a687657ca16cec83c42e95e05e2 (Sun, Jan 1)
arcanist c243cbbd9fc701ca9555672ea5c1666ea154898f (Thu, Dec 29)
phutil 5ac2ca1214890d865bc57fab2715a322fdf02ab6 (Tue, Dec 6)
```