issue_comments: 238081972

Started working on it. Still a lot of cleanup to be done. https://github.com/crusaderky/xarray/commit/8830437865c43e472101ca91a12f714ee43546cc

Observations: - I can't put any sense in the skip_single_target hack or in the whole special treatment inside align() for when there is only one arg. What's the benefit of the whole thing? What would happen if we simply removed the special logic? - DataArray.reindex(copy=False) still performs a copy, even if there's nothing to do. I'm a bit afraid to go and fix it right now as I don't want to trigger domino effects - I'm experiencing a lot of grief because assertDatasetIdentical expects both the coords and the data vars to have the same order, which in some situations it's simply impossible to control without touching vast areas of your code. As a more general and fundamental point, I cannot understand what's the benefit of using OrderedDict instead of a plain dict for coords, attrs, and Dataset.data_vars?