Pull updates with git after cloned with --depth 1

I think you can use --depth 1 in git pull too, so it gets just what's needed for the newest commit in the repository.

I don't know if the default behaviour is to pull everything missing, because my git help pull shows this option:

git pull --unshallow

or

git fetch  --unshallow

--unshallow Convert a shallow repository to a complete one, removing all the limitations imposed by shallow repositories.

I'm running git version 1.8.5.2 (Apple Git-48), and maybe this is some sort-of-new behaviour, and changing a bit between versions.

Could any of the new commits be merge-commits pointing to commits not present in your tree? Perhaps --depth 1000 would work better and still be small enough.