Merge branch 'hn/reftable-prep-part-2'

Further preliminary change to refs API.

* hn/reftable-prep-part-2:
  Make HEAD a PSEUDOREF rather than PER_WORKTREE.
  Modify pseudo refs through ref backend storage
  t1400: use git rev-parse for testing PSEUDOREF existence

Documentation/git-update-ref.txt

@@ -148,12 +148,13 @@ still see a subset of the modifications.
 
 LOGGING UPDATES
 ---------------
-If config parameter "core.logAllRefUpdates" is true and the ref is one under
-"refs/heads/", "refs/remotes/", "refs/notes/", or the symbolic ref HEAD; or
-the file "$GIT_DIR/logs/<ref>" exists then `git update-ref` will append
-a line to the log file "$GIT_DIR/logs/<ref>" (dereferencing all
-symbolic refs before creating the log name) describing the change
-in ref value.  Log lines are formatted as:
+If config parameter "core.logAllRefUpdates" is true and the ref is one
+under "refs/heads/", "refs/remotes/", "refs/notes/", or a pseudoref
+like HEAD or ORIG_HEAD; or the file "$GIT_DIR/logs/<ref>" exists then
+`git update-ref` will append a line to the log file
+"$GIT_DIR/logs/<ref>" (dereferencing all symbolic refs before creating
+the log name) describing the change in ref value.  Log lines are
+formatted as:
 
     oldsha1 SP newsha1 SP committer LF
 

refs.c

@@ -708,10 +708,9 @@ int dwim_log(const char *str, int len, struct object_id *oid, char **log)
 
 static int is_per_worktree_ref(const char *refname)
 {
-	return !strcmp(refname, "HEAD") ||
-		starts_with(refname, "refs/worktree/") ||
-		starts_with(refname, "refs/bisect/") ||
-		starts_with(refname, "refs/rewritten/");
+	return starts_with(refname, "refs/worktree/") ||
+	       starts_with(refname, "refs/bisect/") ||
+	       starts_with(refname, "refs/rewritten/");
 }
 
 static int is_pseudoref_syntax(const char *refname)
@@ -771,102 +770,6 @@ long get_files_ref_lock_timeout_ms(void)
 	return timeout_ms;
 }
 
-static int write_pseudoref(const char *pseudoref, const struct object_id *oid,
-			   const struct object_id *old_oid, struct strbuf *err)
-{
-	const char *filename;
-	int fd;
-	struct lock_file lock = LOCK_INIT;
-	struct strbuf buf = STRBUF_INIT;
-	int ret = -1;
-
-	if (!oid)
-		return 0;
-
-	strbuf_addf(&buf, "%s\n", oid_to_hex(oid));
-
-	filename = git_path("%s", pseudoref);
-	fd = hold_lock_file_for_update_timeout(&lock, filename, 0,
-					       get_files_ref_lock_timeout_ms());
-	if (fd < 0) {
-		strbuf_addf(err, _("could not open '%s' for writing: %s"),
-			    filename, strerror(errno));
-		goto done;
-	}
-
-	if (old_oid) {
-		struct object_id actual_old_oid;
-
-		if (read_ref(pseudoref, &actual_old_oid)) {
-			if (!is_null_oid(old_oid)) {
-				strbuf_addf(err, _("could not read ref '%s'"),
-					    pseudoref);
-				rollback_lock_file(&lock);
-				goto done;
-			}
-		} else if (is_null_oid(old_oid)) {
-			strbuf_addf(err, _("ref '%s' already exists"),
-				    pseudoref);
-			rollback_lock_file(&lock);
-			goto done;
-		} else if (!oideq(&actual_old_oid, old_oid)) {
-			strbuf_addf(err, _("unexpected object ID when writing '%s'"),
-				    pseudoref);
-			rollback_lock_file(&lock);
-			goto done;
-		}
-	}
-
-	if (write_in_full(fd, buf.buf, buf.len) < 0) {
-		strbuf_addf(err, _("could not write to '%s'"), filename);
-		rollback_lock_file(&lock);
-		goto done;
-	}
-
-	commit_lock_file(&lock);
-	ret = 0;
-done:
-	strbuf_release(&buf);
-	return ret;
-}
-
-static int delete_pseudoref(const char *pseudoref, const struct object_id *old_oid)
-{
-	const char *filename;
-
-	filename = git_path("%s", pseudoref);
-
-	if (old_oid && !is_null_oid(old_oid)) {
-		struct lock_file lock = LOCK_INIT;
-		int fd;
-		struct object_id actual_old_oid;
-
-		fd = hold_lock_file_for_update_timeout(
-				&lock, filename, 0,
-				get_files_ref_lock_timeout_ms());
-		if (fd < 0) {
-			error_errno(_("could not open '%s' for writing"),
-				    filename);
-			return -1;
-		}
-		if (read_ref(pseudoref, &actual_old_oid))
-			die(_("could not read ref '%s'"), pseudoref);
-		if (!oideq(&actual_old_oid, old_oid)) {
-			error(_("unexpected object ID when deleting '%s'"),
-			      pseudoref);
-			rollback_lock_file(&lock);
-			return -1;
-		}
-
-		unlink(filename);
-		rollback_lock_file(&lock);
-	} else {
-		unlink(filename);
-	}
-
-	return 0;
-}
-
 int refs_delete_ref(struct ref_store *refs, const char *msg,
 		    const char *refname,
 		    const struct object_id *old_oid,
@@ -875,11 +778,6 @@ int refs_delete_ref(struct ref_store *refs, const char *msg,
 	struct ref_transaction *transaction;
 	struct strbuf err = STRBUF_INIT;
 
-	if (ref_type(refname) == REF_TYPE_PSEUDOREF) {
-		assert(refs == get_main_ref_store(the_repository));
-		return delete_pseudoref(refname, old_oid);
-	}
-
 	transaction = ref_store_transaction_begin(refs, &err);
 	if (!transaction ||
 	    ref_transaction_delete(transaction, refname, old_oid,
@@ -1210,18 +1108,13 @@ int refs_update_ref(struct ref_store *refs, const char *msg,
 	struct strbuf err = STRBUF_INIT;
 	int ret = 0;
 
-	if (ref_type(refname) == REF_TYPE_PSEUDOREF) {
-		assert(refs == get_main_ref_store(the_repository));
-		ret = write_pseudoref(refname, new_oid, old_oid, &err);
-	} else {
-		t = ref_store_transaction_begin(refs, &err);
-		if (!t ||
-		    ref_transaction_update(t, refname, new_oid, old_oid,
-					   flags, msg, &err) ||
-		    ref_transaction_commit(t, &err)) {
-			ret = 1;
-			ref_transaction_free(t);
-		}
+	t = ref_store_transaction_begin(refs, &err);
+	if (!t ||
+	    ref_transaction_update(t, refname, new_oid, old_oid, flags, msg,
+				   &err) ||
+	    ref_transaction_commit(t, &err)) {
+		ret = 1;
+		ref_transaction_free(t);
 	}
 	if (ret) {
 		const char *str = _("update_ref failed for ref '%s': %s");

t/t1400-update-ref.sh

@@ -160,10 +160,10 @@ test_expect_success 'core.logAllRefUpdates=always creates reflog by default' '
 	git reflog exists $outside
 '
 
-test_expect_success 'core.logAllRefUpdates=always creates no reflog for ORIG_HEAD' '
+test_expect_success 'core.logAllRefUpdates=always creates reflog for ORIG_HEAD' '
 	test_config core.logAllRefUpdates always &&
 	git update-ref ORIG_HEAD $A &&
-	test_must_fail git reflog exists ORIG_HEAD
+	git reflog exists ORIG_HEAD
 '
 
 test_expect_success '--no-create-reflog overrides core.logAllRefUpdates=always' '
@@ -475,57 +475,57 @@ test_expect_success 'git cat-file blob master@{2005-05-26 23:42}:F (expect OTHER
 
 test_expect_success 'given old value for missing pseudoref, do not create' '
 	test_must_fail git update-ref PSEUDOREF $A $B 2>err &&
-	test_path_is_missing .git/PSEUDOREF &&
-	test_i18ngrep "could not read ref" err
+	test_must_fail git rev-parse PSEUDOREF &&
+	test_i18ngrep "unable to resolve reference" err
 '
 
 test_expect_success 'create pseudoref' '
 	git update-ref PSEUDOREF $A &&
-	test $A = $(cat .git/PSEUDOREF)
+	test $A = $(git rev-parse PSEUDOREF)
 '
 
 test_expect_success 'overwrite pseudoref with no old value given' '
 	git update-ref PSEUDOREF $B &&
-	test $B = $(cat .git/PSEUDOREF)
+	test $B = $(git rev-parse PSEUDOREF)
 '
 
 test_expect_success 'overwrite pseudoref with correct old value' '
 	git update-ref PSEUDOREF $C $B &&
-	test $C = $(cat .git/PSEUDOREF)
+	test $C = $(git rev-parse PSEUDOREF)
 '
 
 test_expect_success 'do not overwrite pseudoref with wrong old value' '
 	test_must_fail git update-ref PSEUDOREF $D $E 2>err &&
-	test $C = $(cat .git/PSEUDOREF) &&
-	test_i18ngrep "unexpected object ID" err
+	test $C = $(git rev-parse PSEUDOREF) &&
+	test_i18ngrep "cannot lock ref.*expected" err
 '
 
 test_expect_success 'delete pseudoref' '
 	git update-ref -d PSEUDOREF &&
-	test_path_is_missing .git/PSEUDOREF
+	test_must_fail git rev-parse PSEUDOREF
 '
 
 test_expect_success 'do not delete pseudoref with wrong old value' '
 	git update-ref PSEUDOREF $A &&
 	test_must_fail git update-ref -d PSEUDOREF $B 2>err &&
-	test $A = $(cat .git/PSEUDOREF) &&
-	test_i18ngrep "unexpected object ID" err
+	test $A = $(git rev-parse PSEUDOREF) &&
+	test_i18ngrep "cannot lock ref.*expected" err
 '
 
 test_expect_success 'delete pseudoref with correct old value' '
 	git update-ref -d PSEUDOREF $A &&
-	test_path_is_missing .git/PSEUDOREF
+	test_must_fail git rev-parse PSEUDOREF
 '
 
 test_expect_success 'create pseudoref with old OID zero' '
 	git update-ref PSEUDOREF $A $Z &&
-	test $A = $(cat .git/PSEUDOREF)
+	test $A = $(git rev-parse PSEUDOREF)
 '
 
 test_expect_success 'do not overwrite pseudoref with old OID zero' '
 	test_when_finished git update-ref -d PSEUDOREF &&
 	test_must_fail git update-ref PSEUDOREF $B $Z 2>err &&
-	test $A = $(cat .git/PSEUDOREF) &&
+	test $A = $(git rev-parse PSEUDOREF) &&
 	test_i18ngrep "already exists" err
 '
 

t/t1405-main-ref-store.sh

@@ -31,7 +31,10 @@ test_expect_success 'create_symref(FOO, refs/heads/master)' '
 test_expect_success 'delete_refs(FOO, refs/tags/new-tag)' '
 	git rev-parse FOO -- &&
 	git rev-parse refs/tags/new-tag -- &&
-	$RUN delete-refs 0 nothing FOO refs/tags/new-tag &&
+	m=$(git rev-parse master) &&
+	REF_NO_DEREF=1 &&
+	$RUN delete-refs $REF_NO_DEREF nothing FOO refs/tags/new-tag &&
+	test_must_fail git rev-parse --symbolic-full-name FOO &&
 	test_must_fail git rev-parse FOO -- &&
 	test_must_fail git rev-parse refs/tags/new-tag --
 '