File browser truncates file before a long line

When file browser is displaying a file that includes a very long line, that line and everything before it is not shown. The top of the file appears to be the next line after the very long line. There's no indication that the file was truncated and you have to download it to see the whole thing.

Desired fix would be to display the very long line, or at least some of it with an indication that the whole line could not be displayed.

From browsing the source I would guess this is a bug in:

src/main/python/apache/thermos/observer/http/file_browser.py