preview before merge in git
git log ..otherbranch
#=> list of changes that will be merged into current branch.
git diff ...otherbranch
#=> diff from common ancestor (merge base) to the head of what will be merged. Note the three dots.
gitk ...otherbranch
#=> graphical representation of the branches since they were merged last time.
### For the fainted heart (not quite) #####
merge --no-ff --no-commit, and then diff HEAD.
### Push to a branch in origin if not being tracked ###
git push origin HEAD:<remote-branch-name>