Pull Request button on the pulls page does not behave the same as on the repo files page

[richmahn]

Signaling intent to fix an issue we have been bothered by, where the link of the "New Pull Request" button on the Pull Request page of the upstream (main) repo will have the name of the user if the user has a fork of the repo. This should only happen if the user is on the Pull Request page of a fork, not all the time.

For example, user1 has repo1. user2 forks repo1 and thus has their own repo1. Go to user1/repo1's home page (file listing) and the "New Pull Request" button will be correct (http://localhost:3000/user1/repo1/compare/master...master)

but if you go to the "Pull Requests" page, the link of the "New Pull Request" button is http://localhost:3000/user1/repo1/compare/master...user2:repo1

This is not the desired use, nor like how GitHub works, as a user may very well be wanting to make a pull request from a branch of the current repo to the same repo (not from his/her repo). Users have to edit the URL themselves, and most of our users don't understand that.