Merge branch 'js/maint-graft-unhide-true-parents'

* js/maint-graft-unhide-true-parents:
git repack: keep commits hidden by a graft
Add a test showing that 'git repack' throws away grafted-away parents

Conflicts:
git-repack.sh

diff --cc builtin-pack-objects.c
Simple merge

diff --cc cache.h
Simple merge

diff --cc commit.c
Simple merge

diff --cc environment.c
Simple merge

diff --cc git-repack.sh
index 1bf239499c7bdb04622ea6fa239bd7c0ace42065,be0c8435dccabd686ec07808c67f5cf569209ee2..1eb3bca352f38ec3807383cc5fff7f7e62731b2b
--- 1/git-repack.sh
--- 2/git-repack.sh
+++ b/git-repack.sh
@@@ -80,11 -80,13 +80,11 @@@ case ",$all_into_one," i
        ;;
  esac
  
 -args="$args $local $quiet $no_reuse$extra"
 +args="$args $local ${GIT_QUIET:+-q} $no_reuse$extra"
- names=$(git pack-objects --honor-pack-keep --non-empty --all --reflog $args </dev/null "$PACKTMP") ||
+ names=$(git pack-objects --keep-true-parents --honor-pack-keep --non-empty --all --reflog $args </dev/null "$PACKTMP") ||
        exit 1
  if [ -z "$names" ]; then
 -      if test -z "$quiet"; then
 -              echo Nothing new to pack.
 -      fi
 +      say Nothing new to pack.
  fi
  
  # Ok we have prepared all new packfiles.