builtin/refs: add "create" subcommand

The "update" subcommand cannot only update an existing reference, but it
can also create new branches and delete existing branches by specifying
the all-zeroes object ID as either old or new value. Despite that, we
already have the "delete" subcommand as a handy shortcut so that a user
can easily delete a branch. This relieves them of needing to understand
the more arcane uses of the "update" command, and of counting the number
of zeroes they need to pass.

But while we have a "delete" subcommand, we don't have an equivalent
that would allow the user to create a new branch, which creates a
certain asymmetry.

Add a new "create" subcommand to plug this gap.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/Documentation/git-refs.adoc b/Documentation/git-refs.adoc
index 6475bdcc621635aa579bceee2d501eccf5e6b4f8..e6a3528349d2698d4a15cc3ed9aba20773c94fe1 100644 (file)
--- a/Documentation/git-refs.adoc
+++ b/Documentation/git-refs.adoc
@@ -20,6 +20,7 @@ git refs list [--count=<count>] [--shell|--perl|--python|--tcl]
                   [ --stdin | (<pattern>...)]
 git refs exists <ref>
 git refs optimize [--all] [--no-prune] [--auto] [--include <pattern>] [--exclude <pattern>]
+git refs create [--message=<reason>] [--no-deref] [--create-reflog] <ref> <new-value>
 git refs delete [--message=<reason>] [--no-deref] <ref> [<old-value>]
 git refs update [--message=<reason>] [--no-deref] [--create-reflog] <ref> <new-value> [<old-value>]
 
@@ -53,6 +54,10 @@ optimize::
        usage. This subcommand is an alias for linkgit:git-pack-refs[1] and
        offers identical functionality.
 
+create::
+       Create the given reference, which must not already exist, pointing at
+       `<new-value>`.
+
 delete::
        Delete the given reference. This subcommand mirrors `git update-ref -d`
        (see linkgit:git-update-ref[1]). When `<old-value>` is given, the

diff --git a/builtin/refs.c b/builtin/refs.c
index 08453ae1c893cabf6f2a08c2de4df54a783970c1..92e62fd5df933af430d1a49d46c4890a25e34fe0 100644 (file)
--- a/builtin/refs.c
+++ b/builtin/refs.c
@@ -21,6 +21,9 @@
 #define REFS_OPTIMIZE_USAGE \
        N_("git refs optimize " PACK_REFS_OPTS)
 
+#define REFS_CREATE_USAGE \
+       N_("git refs create [--message=<reason>] [--no-deref] [--create-reflog] <ref> <new-value>")
+
 #define REFS_DELETE_USAGE \
        N_("git refs delete [--message=<reason>] [--no-deref] <ref> [<old-value>]")
 
@@ -181,6 +184,53 @@ static int cmd_refs_optimize(int argc, const char **argv, const char *prefix,
        return pack_refs_core(argc, argv, prefix, repo, refs_optimize_usage);
 }
 
+static int cmd_refs_create(int argc, const char **argv, const char *prefix,
+                          struct repository *repo)
+{
+       static char const * const refs_create_usage[] = {
+               REFS_CREATE_USAGE,
+               NULL
+       };
+       const char *message = NULL;
+       unsigned flags = 0;
+       struct option opts[] = {
+               OPT_STRING(0, "message", &message, N_("reason"),
+                          N_("reason of the update")),
+               OPT_BIT(0 ,"no-deref", &flags,
+                       N_("update <refname> not the one it points to"),
+                       REF_NO_DEREF),
+               OPT_BIT(0, "create-reflog", &flags, N_("create a reflog"),
+                       REF_FORCE_CREATE_REFLOG),
+               OPT_END(),
+       };
+       struct object_id newoid;
+       const char *refname;
+       int ret;
+
+       argc = parse_options(argc, argv, prefix, opts, refs_create_usage, 0);
+       if (argc != 2)
+               usage(_("create requires reference name and an object ID"));
+
+       if (message && !*message)
+               die(_("refusing to perform update with empty message"));
+
+       repo_config(repo, git_default_config, NULL);
+
+       refname = argv[0];
+       if (repo_get_oid_with_flags(repo, argv[1], &newoid, GET_OID_SKIP_AMBIGUITY_CHECK))
+               die(_("invalid object ID: '%s'"), argv[1]);
+       if (is_null_oid(&newoid))
+               die(_("cannot create reference with null old object ID"));
+
+       ret = refs_update_ref(get_main_ref_store(repo), message, refname,
+                             &newoid, null_oid(repo->hash_algo), flags,
+                             UPDATE_REFS_MSG_ON_ERR);
+
+       if (ret < 0)
+               ret = 1;
+       return ret;
+}
+
 static int cmd_refs_delete(int argc, const char **argv, const char *prefix,
                           struct repository *repo)
 {
@@ -288,6 +338,7 @@ int cmd_refs(int argc,
                "git refs list " COMMON_USAGE_FOR_EACH_REF,
                REFS_EXISTS_USAGE,
                REFS_OPTIMIZE_USAGE,
+               REFS_CREATE_USAGE,
                REFS_DELETE_USAGE,
                REFS_UPDATE_USAGE,
                NULL,
@@ -299,6 +350,7 @@ int cmd_refs(int argc,
                OPT_SUBCOMMAND("list", &fn, cmd_refs_list),
                OPT_SUBCOMMAND("exists", &fn, cmd_refs_exists),
                OPT_SUBCOMMAND("optimize", &fn, cmd_refs_optimize),
+               OPT_SUBCOMMAND("create", &fn, cmd_refs_create),
                OPT_SUBCOMMAND("delete", &fn, cmd_refs_delete),
                OPT_SUBCOMMAND("update", &fn, cmd_refs_update),
                OPT_END(),

diff --git a/t/meson.build b/t/meson.build
index 2063962dabae67c19ce416c5918e91e3efba0f65..541e6f919c5561bc4254e47011fe0914d3efa3b6 100644 (file)
--- a/t/meson.build
+++ b/t/meson.build
@@ -225,6 +225,7 @@ integration_tests = [
   't1463-refs-optimize.sh',
   't1464-refs-delete.sh',
   't1465-refs-update.sh',
+  't1466-refs-create.sh',
   't1500-rev-parse.sh',
   't1501-work-tree.sh',
   't1502-rev-parse-parseopt.sh',

diff --git a/t/t1466-refs-create.sh b/t/t1466-refs-create.sh
new file mode 100755 (executable)
index 0000000..85c8bd6
--- /dev/null
+++ b/t/t1466-refs-create.sh
@@ -0,0 +1,151 @@
+#!/bin/sh
+
+test_description='git refs create'
+
+. ./test-lib.sh
+
+setup_repo () {
+       git init "$1" &&
+       test_commit -C "$1" A &&
+       test_commit -C "$1" B
+}
+
+test_ref_matches () {
+       git rev-parse "$1" >expect &&
+       echo "$2" >actual &&
+       test_cmp expect actual
+}
+
+test_expect_success 'create a new reference' '
+       test_when_finished "rm -rf repo" &&
+       setup_repo repo &&
+       (
+               cd repo &&
+               A=$(git rev-parse A) &&
+               git refs create refs/heads/foo $A &&
+               test_ref_matches refs/heads/foo "$A"
+       )
+'
+
+test_expect_success 'create fails when the reference already exists' '
+       test_when_finished "rm -rf repo" &&
+       setup_repo repo &&
+       (
+               cd repo &&
+               A=$(git rev-parse A) &&
+               B=$(git rev-parse B) &&
+               git refs create refs/heads/foo $A &&
+               test_must_fail git refs create refs/heads/foo $B 2>err &&
+               test_grep "reference already exists" err &&
+               test_ref_matches refs/heads/foo "$A"
+       )
+'
+
+test_expect_success 'create with null new value fails' '
+       test_when_finished "rm -rf repo" &&
+       setup_repo repo &&
+       (
+               cd repo &&
+               test_must_fail git refs create refs/heads/foo $ZERO_OID 2>err &&
+               test_grep "null old object ID" err &&
+               test_must_fail git refs exists refs/heads/foo
+       )
+'
+
+test_expect_success 'create with invalid new value fails' '
+       test_when_finished "rm -rf repo" &&
+       setup_repo repo &&
+       (
+               cd repo &&
+               test_must_fail git refs create refs/heads/foo invalid-oid 2>err &&
+               test_grep "invalid object ID" err &&
+               test_must_fail git refs exists refs/heads/foo
+       )
+'
+
+test_expect_success 'create does not create a reflog by default' '
+       test_when_finished "rm -rf repo" &&
+       setup_repo repo &&
+       (
+               cd repo &&
+               A=$(git rev-parse A) &&
+               git refs create refs/foo $A &&
+               test_must_fail git reflog exists refs/foo
+       )
+'
+
+test_expect_success 'create creates a reflog with --create-reflog' '
+       test_when_finished "rm -rf repo" &&
+       setup_repo repo &&
+       (
+               cd repo &&
+               A=$(git rev-parse A) &&
+               git refs create --create-reflog refs/foo $A &&
+               git reflog exists refs/foo
+       )
+'
+
+test_expect_success 'create with message records reason in reflog' '
+       test_when_finished "rm -rf repo" &&
+       setup_repo repo &&
+       (
+               cd repo &&
+               A=$(git rev-parse A) &&
+               git refs create --message="create reason" refs/heads/foo $A &&
+               git reflog show refs/heads/foo >actual &&
+               test_grep "create reason$" actual
+       )
+'
+
+test_expect_success 'create with symref target creates target reference' '
+       test_when_finished "rm -rf repo" &&
+       setup_repo repo &&
+       (
+               cd repo &&
+               A=$(git rev-parse A) &&
+               git symbolic-ref refs/heads/symref refs/heads/target &&
+               git refs create refs/heads/symref $A &&
+               git reflog exists refs/heads/target
+       )
+'
+
+test_expect_success 'create with symref target and --no-deref refuses to create reference' '
+       test_when_finished "rm -rf repo" &&
+       setup_repo repo &&
+       (
+               cd repo &&
+               A=$(git rev-parse A) &&
+               git symbolic-ref refs/heads/symref refs/heads/target &&
+               test_must_fail git refs create --no-deref refs/heads/symref $A 2>err &&
+               test_grep "dangling symref already exists" err &&
+               test_must_fail git reflog exists refs/heads/target
+       )
+'
+
+test_expect_success 'create with empty message fails' '
+       test_when_finished "rm -rf repo" &&
+       setup_repo repo &&
+       (
+               cd repo &&
+               A=$(git rev-parse A) &&
+               test_must_fail git refs create --message= refs/heads/foo $A 2>err &&
+               test_grep "empty message" err &&
+               test_must_fail git refs exists refs/heads/foo
+       )
+'
+
+test_expect_success 'create without arguments fails' '
+       test_when_finished "rm -rf repo" &&
+       setup_repo repo &&
+       test_must_fail git -C repo refs create 2>err &&
+       test_grep "requires reference name" err
+'
+
+test_expect_success 'create with too many arguments fails' '
+       test_when_finished "rm -rf repo" &&
+       setup_repo repo &&
+       test_must_fail git -C repo refs create refs/heads/foo a b 2>err &&
+       test_grep "requires reference name" err
+'
+
+test_done