LineHighlighter doesn't work for multiple lines

Summary

Line highligther doesn't work for multiple lines. And also gitlab is using it's own format, if I undersand the code right: https://gitlab.com/trakt/script.trakt/blob/master/changelog.txt#L12-20 vs https://github.com/trakt/script.trakt/blob/master/changelog.txt#L12-L20

(the L at the end)

Steps to reproduce

• Call this link https://gitlab.com/trakt/script.trakt/blob/master/changelog.txt#L12-20
• See that it only highlights one line

Example Project

https://gitlab.com/trakt/script.trakt/blob/master/changelog.txt#L12-20

What is the current bug behavior?

Only the first line get highlighted

What is the expected correct behavior?

All lines from XX-YY should highlight when passing LXX-YY

Output of checks

This bug happens on GitLab.com

Possible fixes

It has to be somewhere around here https://gitlab.com/gitlab-org/gitlab-ce/blob/master/app/assets/javascripts/line_highlighter.js#L121