When you did this:
$ git fetch origin
you did not receive the origin / master branch. Suppose you got an origin / other. Then when you are done:
$ git merge remotes/origin/master
because there was nothing new in origin / master (you never brought it), there was nothing to merge. You have "already updated". As you know, when you did this:
$ git pull origin
, 'pull' (origin/other), (of origin/other). , "pull" "push"
$ git remote show origin
:
$ git checkout master
$ git branch --track master origin/master