Merge branch 'tn/stash-avoid-sparse-index-expansion'

Merge branch 'tn/stash-avoid-sparse-index-expansion'

The 'git stash push' command has been optimized to avoid unnecessary
sparse index expansion when pathspecs are wholly inside the
sparse-checkout cone.  Also, a potential out-of-bounds read in the
sparse-index expansion check helper pathspec_needs_expanded_index()
has been fixed by consistently using the parsed, prefixed path.

* tn/stash-avoid-sparse-index-expansion:
  stash: avoid sparse-index expansion for in-cone paths
  pathspec: use match for sparse-index expansion checks