Re: [PATCH v2 2/2] completion: add a GIT_COMPLETION_SHOW_ALL_COMMANDS

SZEDER Gábor [off-list ref] writes:

Superficial testing shows that it appears to work in common cases, but
we'll have to think it through when and how to clear these variables.
E.g.:

  $ git d<TAB><TAB>
  describe   diff   difftool
  # Oh, but I wanted to disable the pager
  $ git --no-p<TAB>
  # this completes the option uniquely
  $ git --no-pager d<TAB><TAB>
  daemon     diff         diff-index   diff-tree
  describe   diff-files   difftool

I think here it should list only porcelains, but because both those
last_cur variables still contain 'd', it lists plumbing as well.

Yup, it always is tricky to "invalidate" a cached value.