Re: a few remaining issues...

Junio C Hamano writes:
 > * Handling paths that are unknown to the index.
 > 
 > I sent out patches tonight to teach "git reset <tree> -- <path>"
 > to restore the absense of path in the index from the tree
 > tonight.  There was another one recently brought up on the list:
 > "git commit -- <path>" for path that is no longer known to the
 > index.  While jumping the index is a practice I particularly do
 > not want to encourage by extending git to support it, we already
 > have support for most of the cases, so I think it makes sense to
 > do this for consistency.  I haven't thought about the necessary
 > changes yet, so people can beat me if they want to.  My vague
 > idea is to check HEAD to see if <path> exists and if so refrain
 > from complaining.

This looks like a job for your para-walk topic. For this git-commit case we just need a

  git-ls --no-workdir --error-unmatch HEAD -- <pattern>...

to replace git-ls-files. To my untrained eyes it looks like this is mostly there (AFAICS it doesn't do pattern matching and the --error-unmatch thingy).