Merge branch 'jc/maint-1.6.0-keep-pack' into maint

* jc/maint-1.6.0-keep-pack:
pack-objects: don't loosen objects available in alternate or kept packs
t7700: demonstrate repack flaw which may loosen objects unnecessarily
Remove --kept-pack-only option and associated infrastructure
pack-objects: only repack or loosen objects residing in "local" packs
git-repack.sh: don't use --kept-pack-only option to pack-objects
t7700-repack: add two new tests demonstrating repacking flaws
is_kept_pack(): final clean-up
Simplify is_kept_pack()
Consolidate ignore_packed logic more
has_sha1_kept_pack(): take "struct rev_info"
has_sha1_pack(): refactor "pretend these packs do not exist" interface
git-repack: resist stray environment variable

Conflicts:
t/t7700-repack.sh

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

diff --cc builtin-fsck.c
Simple merge

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

diff --cc cache.h
index 189151de25ffd1a6671b7a70f359fa9b94b82173,23c16d0d99777cc9a6f23c6b23fb16d837b1742c..50179687b5fc9ed37933d06bb4cbfe988ce8b6c9
--- 1/cache.h
--- 2/cache.h
+++ b/cache.h
@@@ -836,10 -744,9 +836,9 @@@ extern const unsigned char *nth_packed_
  extern off_t nth_packed_object_offset(const struct packed_git *, uint32_t);
  extern off_t find_pack_entry_one(const unsigned char *, struct packed_git *);
  extern void *unpack_entry(struct packed_git *, off_t, enum object_type *, unsigned long *);
 -extern unsigned long unpack_object_header_gently(const unsigned char *buf, unsigned long len, enum object_type *type, unsigned long *sizep);
 +extern unsigned long unpack_object_header_buffer(const unsigned char *buf, unsigned long len, enum object_type *type, unsigned long *sizep);
  extern unsigned long get_size_from_delta(struct packed_git *, struct pack_window **, off_t);
  extern const char *packed_object_info_detail(struct packed_git *, off_t, unsigned long *, unsigned long *, unsigned int *, unsigned char *);
- extern int matches_pack_name(struct packed_git *p, const char *name);
  
  /* Dumb servers support */
  extern int update_server_info(int);

diff --cc diff.c
Simple merge

diff --cc git-repack.sh
Simple merge

diff --cc revision.c
Simple merge

diff --cc revision.h
Simple merge

diff --cc sha1_file.c
index a07aa4e5c491d16f65bc109673e806e24efb2274,500fd93127246fad72edca165fd4673070813f82..37e833b77d1ee556d18256154073a706ab11b3a4
--- 1/sha1_file.c
--- 2/sha1_file.c
+++ b/sha1_file.c
@@@ -2046,17 -1956,10 +2019,17 @@@ int sha1_object_info(const unsigned cha
  
                /* Not a loose object; someone else may have just packed it. */
                reprepare_packed_git();
-               if (!find_pack_entry(sha1, &e, NULL))
+               if (!find_pack_entry(sha1, &e))
                        return status;
        }
 -      return packed_object_info(e.p, e.offset, sizep);
 +
 +      status = packed_object_info(e.p, e.offset, sizep);
 +      if (status < 0) {
 +              mark_bad_packed_object(e.p, sha1);
 +              status = sha1_object_info(sha1, sizep);
 +      }
 +
 +      return status;
  }
  
  static void *read_packed_sha1(const unsigned char *sha1,

diff --cc t/t7700-repack.sh
index f5682d66db2832311774fb68b7264002dfeb091f,9ce546e3b225563279c54eb6ceafd87398a3e5cc..6b29bff782f5a46bb6970d70598fd3be82c679fa
--- 1/t/t7700-repack.sh
--- 2/t/t7700-repack.sh
+++ b/t/t7700-repack.sh
@@@ -69,24 -69,66 +69,85 @@@ test_expect_success 'packed obs in alt 
        done
  '
  
 +test_expect_failure 'packed obs in alt ODB are repacked when local repo has packs' '
 +      rm -f .git/objects/pack/* &&
 +      echo new_content >> file1 &&
 +      git add file1 &&
 +      git commit -m more_content &&
 +      git repack &&
 +      git repack -a -d &&
 +      myidx=$(ls -1 .git/objects/pack/*.idx) &&
 +      test -f "$myidx" &&
 +      for p in alt_objects/pack/*.idx; do
 +              git verify-pack -v $p | sed -n -e "/^[0-9a-f]\{40\}/p"
 +      done | while read sha1 rest; do
 +              if ! ( git verify-pack -v $myidx | grep "^$sha1" ); then
 +                      echo "Missing object in local pack: $sha1"
 +                      return 1
 +              fi
 +      done
 +'
 +
+ test_expect_success 'packed obs in alternate ODB kept pack are repacked' '
+       # swap the .keep so the commit object is in the pack with .keep
+       for p in alt_objects/pack/*.pack
+       do
+               base_name=$(basename $p .pack)
+               if test -f alt_objects/pack/$base_name.keep
+               then
+                       rm alt_objects/pack/$base_name.keep
+               else
+                       touch alt_objects/pack/$base_name.keep
+               fi
+       done
+       git repack -a -d &&
+       myidx=$(ls -1 .git/objects/pack/*.idx) &&
+       test -f "$myidx" &&
+       for p in alt_objects/pack/*.idx; do
+               git verify-pack -v $p | sed -n -e "/^[0-9a-f]\{40\}/p"
+       done | while read sha1 rest; do
+               if ! ( git verify-pack -v $myidx | grep "^$sha1" ); then
+                       echo "Missing object in local pack: $sha1"
+                       return 1
+               fi
+       done
+ '
+ 
+ test_expect_success 'packed unreachable obs in alternate ODB are not loosened' '
+       rm -f alt_objects/pack/*.keep &&
+       mv .git/objects/pack/* alt_objects/pack/ &&
+       csha1=$(git rev-parse HEAD^{commit}) &&
+       git reset --hard HEAD^ &&
+       sleep 1 &&
+       git reflog expire --expire=now --expire-unreachable=now --all &&
+       # The pack-objects call on the next line is equivalent to
+       # git repack -A -d without the call to prune-packed
+       git pack-objects --honor-pack-keep --non-empty --all --reflog \
+           --unpack-unreachable </dev/null pack &&
+       rm -f .git/objects/pack/* &&
+       mv pack-* .git/objects/pack/ &&
+       test 0 = $(git verify-pack -v -- .git/objects/pack/*.idx |
+               egrep "^$csha1 " | sort | uniq | wc -l) &&
+       echo > .git/objects/info/alternates &&
+       test_must_fail git show $csha1
+ '
+ 
+ test_expect_success 'local packed unreachable obs that exist in alternate ODB are not loosened' '
+       echo `pwd`/alt_objects > .git/objects/info/alternates &&
+       echo "$csha1" | git pack-objects --non-empty --all --reflog pack &&
+       rm -f .git/objects/pack/* &&
+       mv pack-* .git/objects/pack/ &&
+       # The pack-objects call on the next line is equivalent to
+       # git repack -A -d without the call to prune-packed
+       git pack-objects --honor-pack-keep --non-empty --all --reflog \
+           --unpack-unreachable </dev/null pack &&
+       rm -f .git/objects/pack/* &&
+       mv pack-* .git/objects/pack/ &&
+       test 0 = $(git verify-pack -v -- .git/objects/pack/*.idx |
+               egrep "^$csha1 " | sort | uniq | wc -l) &&
+       echo > .git/objects/info/alternates &&
+       test_must_fail git show $csha1
+ '
+ 
  test_done