[PULL maint] two fast-import "ls" fixes

Jonathan Nieder wrote:

After sleeping on it, here are two patches for 'maint'.

For your convenience, these changes can also be found at:

  git://repo.or.cz/git/jrn.git tags/fast-import-ls-fixes

      fast-import: leakfix for 'ls' of dirty trees
      fast-import: don't allow 'ls' of path with empty components

 fast-import.c          |    4 ++++
 t/t9300-fast-import.sh |   39 +++++++++++++++++++++++++++++++++++++++
 2 files changed, 43 insertions(+)