git-reflog: add exists command

This is necessary because alternate ref backends might store reflogs
somewhere other than .git/logs.  Code that now directly manipulates
.git/logs should instead go through git-reflog.

Signed-off-by: David Turner <dturner@twopensource.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/Documentation/git-reflog.txt b/Documentation/git-reflog.txt
index 5e7908e4f705d858dca8483069fd3b89c8f7e31c..44c736f1a8e581bc072d5de3b719284f7376ec3b 100644 (file)
--- a/Documentation/git-reflog.txt
+++ b/Documentation/git-reflog.txt
@@ -23,6 +23,7 @@ depending on the subcommand:
        [--dry-run] [--verbose] [--all | <refs>...]
 'git reflog delete' [--rewrite] [--updateref]
        [--dry-run] [--verbose] ref@\{specifier\}...
        [--dry-run] [--verbose] [--all | <refs>...]
 'git reflog delete' [--rewrite] [--updateref]
        [--dry-run] [--verbose] ref@\{specifier\}...

+'git reflog exists' <ref>

 
 Reference logs, or "reflogs", record when the tips of branches and
 other references were updated in the local repository. Reflogs are
 
 Reference logs, or "reflogs", record when the tips of branches and
 other references were updated in the local repository. Reflogs are


@@ -52,6 +53,9 @@ argument must be an _exact_ entry (e.g. "`git reflog delete
 master@{2}`"). This subcommand is also typically not used directly by
 end users.
 
 master@{2}`"). This subcommand is also typically not used directly by
 end users.
 

+The "exists" subcommand checks whether a ref has a reflog.  It exits
+with zero status if the reflog exists, and non-zero status if it does
+not.

 
 OPTIONS
 -------
 
 OPTIONS
 -------

diff --git a/builtin/reflog.c b/builtin/reflog.c
index c2eb8ff8402068d7480a3afd262219cb03841ae1..7ed0e8501c149312676c0bce6fa52372a11b6fff 100644 (file)
--- a/builtin/reflog.c
+++ b/builtin/reflog.c
@@ -13,6 +13,8 @@ static const char reflog_expire_usage[] =
 "git reflog expire [--expire=<time>] [--expire-unreachable=<time>] [--rewrite] [--updateref] [--stale-fix] [--dry-run | -n] [--verbose] [--all] <refs>...";
 static const char reflog_delete_usage[] =
 "git reflog delete [--rewrite] [--updateref] [--dry-run | -n] [--verbose] <refs>...";
 "git reflog expire [--expire=<time>] [--expire-unreachable=<time>] [--rewrite] [--updateref] [--stale-fix] [--dry-run | -n] [--verbose] [--all] <refs>...";
 static const char reflog_delete_usage[] =
 "git reflog delete [--rewrite] [--updateref] [--dry-run | -n] [--verbose] <refs>...";

+static const char reflog_exists_usage[] =
+"git reflog exists <ref>";

 
 static unsigned long default_reflog_expire;
 static unsigned long default_reflog_expire_unreachable;
 
 static unsigned long default_reflog_expire;
 static unsigned long default_reflog_expire_unreachable;


@@ -699,12 +701,38 @@ static int cmd_reflog_delete(int argc, const char **argv, const char *prefix)
        return status;
 }
 
        return status;
 }
 

+static int cmd_reflog_exists(int argc, const char **argv, const char *prefix)
+{
+       int i, start = 0;
+
+       for (i = 1; i < argc; i++) {
+               const char *arg = argv[i];
+               if (!strcmp(arg, "--")) {
+                       i++;
+                       break;
+               }
+               else if (arg[0] == '-')
+                       usage(reflog_exists_usage);
+               else
+                       break;
+       }
+
+       start = i;
+
+       if (argc - start != 1)
+               usage(reflog_exists_usage);
+
+       if (check_refname_format(argv[start], REFNAME_ALLOW_ONELEVEL))
+               die("invalid ref format: %s", argv[start]);
+       return !reflog_exists(argv[start]);
+}
+

 /*
  * main "reflog"
  */
 
 static const char reflog_usage[] =
 /*
  * main "reflog"
  */
 
 static const char reflog_usage[] =

-"git reflog [ show | expire | delete ]";
+"git reflog [ show | expire | delete | exists ]";

 
 int cmd_reflog(int argc, const char **argv, const char *prefix)
 {
 
 int cmd_reflog(int argc, const char **argv, const char *prefix)
 {


@@ -724,5 +752,8 @@ int cmd_reflog(int argc, const char **argv, const char *prefix)
        if (!strcmp(argv[1], "delete"))
                return cmd_reflog_delete(argc - 1, argv + 1, prefix);
 
        if (!strcmp(argv[1], "delete"))
                return cmd_reflog_delete(argc - 1, argv + 1, prefix);
 

+       if (!strcmp(argv[1], "exists"))
+               return cmd_reflog_exists(argc - 1, argv + 1, prefix);
+

        return cmd_log_reflog(argc, argv, prefix);
 }
        return cmd_log_reflog(argc, argv, prefix);
 }

diff --git a/t/t1411-reflog-show.sh b/t/t1411-reflog-show.sh
index 6f47c0dd0ec9b5e59205ca98eea9bd729605e004..3eb4f102e505445041a3772404523a99245a8346 100755 (executable)
--- a/t/t1411-reflog-show.sh
+++ b/t/t1411-reflog-show.sh
@@ -166,4 +166,9 @@ test_expect_success 'git log -g -p shows diffs vs. parents' '
        test_cmp expect actual
 '
 
        test_cmp expect actual
 '
 

+test_expect_success 'reflog exists works' '
+       git reflog exists refs/heads/master &&
+       ! git reflog exists refs/heads/nonexistent
+'
+

 test_done
 test_done