Merge branch 'ms/refs-optimize' into next

"git refs optimize" is added for not very well explained reason
despite it does the same thing as "git pack-refs"...

* ms/refs-optimize:
  t: add test for git refs optimize subcommand
  t0601: refactor tests to be shareable
  builtin/refs: add optimize subcommand
  doc: pack-refs: factor out common options
  builtin/pack-refs: factor out core logic into a shared library
  builtin/pack-refs: convert to use the generic refs_optimize() API
  reftable-backend: implement 'optimize' action
  files-backend: implement 'optimize' action
  refs: add a generic 'optimize' API

diff --cc Documentation/git-refs.adoc
index bfa9b3ea2d8b19770fe43f5623af8c6266512da5,e233f21eeb528af6ae49f1e3438b00246ca94e95..fa33680cc781fe279d123eb1643c96fda0780433
--- 1/Documentation/git-refs.adoc
--- 2/Documentation/git-refs.adoc
+++ b/Documentation/git-refs.adoc
@@@ -18,7 -18,7 +18,8 @@@ git refs list [--count=<count>] [--shel
                   [--contains[=<object>]] [--no-contains[=<object>]]
                   [(--exclude=<pattern>)...] [--start-after=<marker>]
                   [ --stdin | (<pattern>...)]
 +git refs exists <ref>
+ git refs optimize [--all] [--no-prune] [--auto] [--include <pattern>] [--exclude <pattern>]
  
  DESCRIPTION
  -----------
@@@ -39,12 -39,11 +40,17 @@@ list:
        formatting, and sorting. This subcommand is an alias for
        linkgit:git-for-each-ref[1] and offers identical functionality.
  
 +exists::
 +      Check whether the given reference exists. Returns an exit code of 0 if
 +      it does, 2 if it is missing, and 1 in case looking up the reference
 +      failed with an error other than the reference being missing. This does
 +      not verify whether the reference resolves to an actual object.
 +
+ optimize::
+       Optimizes references to improve repository performance and reduce disk
+       usage. This subcommand is an alias for linkgit:git-pack-refs[1] and
+       offers identical functionality.
+ 
  OPTIONS
  -------
  

diff --cc Makefile
Simple merge

diff --cc builtin/refs.c
index 91548783b75b589b957bf0cce8f5b425ffab56fb,785f476e4b9f9aacf05202e0e2512d87b6fbbbcd..3064f888b24304ce07dba107be137ad8d420e731
--- 1/builtin/refs.c
--- 2/builtin/refs.c
+++ b/builtin/refs.c
@@@ -15,9 -15,9 +16,12 @@@
  #define REFS_VERIFY_USAGE \
        N_("git refs verify [--strict] [--verbose]")
  
 +#define REFS_EXISTS_USAGE \
 +      N_("git refs exists <ref>")
 +
+ #define REFS_OPTIMIZE_USAGE \
+       N_("git refs optimize " PACK_REFS_OPTS)
+ 
  static int cmd_refs_migrate(int argc, const char **argv, const char *prefix,
                            struct repository *repo UNUSED)
  {
@@@ -117,48 -117,17 +121,59 @@@ static int cmd_refs_list(int argc, cons
        return for_each_ref_core(argc, argv, prefix, repo, refs_list_usage);
  }
  
 +static int cmd_refs_exists(int argc, const char **argv, const char *prefix,
 +                         struct repository *repo UNUSED)
 +{
 +      struct strbuf unused_referent = STRBUF_INIT;
 +      struct object_id unused_oid;
 +      unsigned int unused_type;
 +      int failure_errno = 0;
 +      const char *ref;
 +      int ret = 0;
 +      const char * const exists_usage[] = {
 +              REFS_EXISTS_USAGE,
 +              NULL,
 +      };
 +      struct option options[] = {
 +              OPT_END(),
 +      };
 +
 +      argc = parse_options(argc, argv, prefix, options, exists_usage, 0);
 +      if (argc != 1)
 +              die(_("'git refs exists' requires a reference"));
 +
 +      ref = *argv++;
 +      if (refs_read_raw_ref(get_main_ref_store(the_repository), ref,
 +                            &unused_oid, &unused_referent, &unused_type,
 +                            &failure_errno)) {
 +              if (failure_errno == ENOENT || failure_errno == EISDIR) {
 +                      error(_("reference does not exist"));
 +                      ret = 2;
 +              } else {
 +                      errno = failure_errno;
 +                      error_errno(_("failed to look up reference"));
 +                      ret = 1;
 +              }
 +
 +              goto out;
 +      }
 +
 +out:
 +      strbuf_release(&unused_referent);
 +      return ret;
 +}
 +
+ static int cmd_refs_optimize(int argc, const char **argv, const char *prefix,
+                            struct repository *repo)
+ {
+       static char const * const refs_optimize_usage[] = {
+               REFS_OPTIMIZE_USAGE,
+               NULL
+       };
+ 
+       return pack_refs_core(argc, argv, prefix, repo, refs_optimize_usage);
+ }
+ 
  int cmd_refs(int argc,
             const char **argv,
             const char *prefix,
@@@ -168,7 -137,7 +183,8 @@@
                REFS_MIGRATE_USAGE,
                REFS_VERIFY_USAGE,
                "git refs list " COMMON_USAGE_FOR_EACH_REF,
 +              REFS_EXISTS_USAGE,
+               REFS_OPTIMIZE_USAGE,
                NULL,
        };
        parse_opt_subcommand_fn *fn = NULL;
@@@ -176,7 -145,7 +192,8 @@@
                OPT_SUBCOMMAND("migrate", &fn, cmd_refs_migrate),
                OPT_SUBCOMMAND("verify", &fn, cmd_refs_verify),
                OPT_SUBCOMMAND("list", &fn, cmd_refs_list),
 +              OPT_SUBCOMMAND("exists", &fn, cmd_refs_exists),
+               OPT_SUBCOMMAND("optimize", &fn, cmd_refs_optimize),
                OPT_END(),
        };
  

diff --cc meson.build
Simple merge

diff --cc refs.c
Simple merge

diff --cc refs.h
Simple merge

diff --cc refs/files-backend.c
Simple merge

diff --cc refs/reftable-backend.c
Simple merge

diff --cc t/meson.build
index 7974795fe48c3a3684b5f14addd167648c364727,92327aabdfb44ba5f622038eb78187ffe19bad44..d87166c0db7806fcbee8a23b1996b4fa31a6db28
--- 1/t/meson.build
--- 2/t/meson.build
+++ b/t/meson.build
@@@ -212,7 -211,7 +212,8 @@@ integration_tests = 
    't1451-fsck-buffer.sh',
    't1460-refs-migrate.sh',
    't1461-refs-list.sh',
 +  't1462-refs-exists.sh',
+   't1463-refs-optimize.sh',
    't1500-rev-parse.sh',
    't1501-work-tree.sh',
    't1502-rev-parse-parseopt.sh',