Users send each other links such as https://secure.phabricator.com/diffusion/P/browse/master/README.md$22, expecting to direct the precipitant to line 22 in the file; If the recipient has somehow disabled source highlighting on the file, the link just shows the file, confusing both users.

I'm pretty sure the user disabled this either by mistake, or in order to copy something (ie, they assume that "copy" will not work correctly out of a formatted page).

I don't think we can realistically highlight part of the plain-text view, but maybe there's some way we can reduce the confusion here?

Some random ideas:

• if the link has $22, turn on highlighting?
• revert the settings back to highlight + blame after a week / browser session?
• disable plain-text mode for diffusion?