bing search plugin shipped with tor browser should use https
If I use the search window in tor browser to do a bing web search, the search is done via an HTTP. If I manually change the URL to HTTPS the search also works.
It seems that https-everywhere has a rule for bing, but it is marked as buggy and disabled by default.
I don't see why the search plugin shouldn't use a HTTPS url though, as it apparently works without problems.