If you just want to "view the patch", you should not do "pull". In general, I recommend against "pull", as I think it is somewhat distressingly magical. I recommend "fetch" and "merge" (or rebase) as separate steps. I'm also not sure the instructions as given here actually work.

I would do:

# Add a new git remote

git remote add otherpersonname https://github.com/otherpersonname/oh-mainline.g
git fetch otherpersonname

git checkout otherpersonname/theirbranchname -b theirbranchname