Expand/Collapse full source code links don't work on comments list

[morganestes]

When viewing the comments list and previewing the submitted code, I get "Expand full source codeCollapse full source code" at the bottom of the code, above the moderation links. There are two separate links there smushed together, and neither one affect the code view at all, they just jump back to the top of the page.

[morganestes]

Expand/Collapse links

[atimmer]

This is probably because the syntax highlighter script doesn't get loaded in the admin. I think we have two options:

• Enqueue the syntax highlighter scripts ourselves on the comment moderation page(s).
• Add an if ( ! is_admin ) { clause around this code to prevent the collapsing from taking place in the admin.

[coffee2code]

In 1822:

developer.wordpress.org: Don't show expand/collapse source code links in admin.

Fixes #1179.
Props atimmer.