Good morning Frank, *,

vcs_info git false-negatives to detect staged changes in a repository that has
no commits.  Attached a patch for that.

The patch includes two variants for computing the "has staged changes?" bit in
empty repositories: one via 'git ls-files' and one via git's empty tree.

- The output of ls-files isn't O(1), but I tested with a 3000-file tree and
  didn't notice a slowdown, so I suppose it's acceptable.

- 'diff-index --cached --quiet $empty_tree' is an O(1) operation, but I am not
  sure whether it is forwards compatible with future versions of Git, i.e.,
  whether it's a hack that happens to work or a legitimate use of git's API.

WDYT?

Daniel