My 2c on this:
1) "If the --keep-index option is used, all changes already added to the
index are left intact" (manpage git stash)
That appears to be correct and clear
2) "$ git stash push --keep-index # save *all other* changes to the
stash" (manpage git stash)
That is either not correct or misleading. "All other" implies in my
opinion all changes
except the ones that were already added. *"All changes including already
staged changes"*
might be a better choice.
Please also see open question on StackOverflow:
https://stackoverflow.com/questions/50242489/how-to-ignore-added-hunks-in-git-stash-p/
