Merge branch 'ah/doc-filter-branch-export-env' into maint

Docfix. * ah/doc-filter-branch-export-env: doc: filter-branch does not require re-export of vars

Junio C Hamano committed Jun 5, 2017 at 09:03 UTC f166aab8bf877d7448f5bc7257fd43db66983a55

No changes.