buffer stuck in right-to-left mode

[afukumoto]

Using GNU Emacs 25.2.1, I experienced that the twittering-mode buffer is stuck in right-to-left mode when a tweet contained persian characters, and all later tweets are displayed right-to-left. In particular, it occured when http://twitter.com/mojimojicafe/status/969212556794478594 was displayed.

Setting the variable bidi-paragraph-direction explicitly to left-to-right resolved this particular case for me, though I don't know what's the correct fix.