How can I make Firefox word-wrap text/plain files?

When I view this IRC log in Firefox, long lines do not wrap. But I wish they would! Anyone know how to make Firefox word-wrap text/plain files?

• this file is served as gzipped plain text; try HEAD http://ci.mifos.org/irclogs/%23mifos/archive/2010/2010-01-04.log.gz and you should see Content-Type: text/plain
• when the same resource is viewed in Google Chrome, long lines wrap
• this might be a related question on doctype, but the "accepted answer" contains a broken link
• this didn't work for me (even the alternate version using pre-wrap as opposed to -moz-pre-wrap mentioned in a comment by user "Idran")
• using "View → Page Source", then toggling word wrap is a suitable workaround

Solution 1:

The Toggle Word Wrap Firefox extension might work for you.

Solution 2:

FF 31. Open a new tab.

Enter about:config in the Awesome Bar.

Search for view_source.wrap_long_lines and set value to true.

Solution 3:

If you just need to wrap plaintext files, try Ctrl-U (then View -> Wrap Long Lines, if not already checked). This solution is cleaner than an add-in with plaintext files, but sloppier with text embedded in html.