Signed-off-by: Bence Ferdinandy <redacted>
---

Notes:
     v4: new patch
     
     v5: - added before_target to reftables backend
         - added an extra safety check for transaction's existence in refs.c
     
     v6: - no change
     
     v7: - remove the whole before_target concept from the backends and
           handle checking it in refs.c instead (thanks Karthik)
         - rename the before_target to referent which is how the same concept
           is called in the backends
         - change commit prefix to be more in line with project standards

  builtin/branch.c          |  2 +-
  builtin/checkout.c        |  4 ++--
  builtin/clone.c           |  6 +++---
  builtin/notes.c           |  2 +-
  builtin/remote.c          |  6 +++---
  builtin/symbolic-ref.c    |  2 +-
  builtin/worktree.c        |  2 +-
  refs.c                    | 16 +++++++++++-----
  refs.h                    |  3 ++-
  reset.c                   |  2 +-
  sequencer.c               |  2 +-
  setup.c                   |  2 +-
  t/helper/test-ref-store.c |  2 +-
  13 files changed, 29 insertions(+), 22 deletions(-)

diff --git a/builtin/branch.c b/builtin/branch.c
index fd1611ebf5..6c87690b58 100644
--- a/builtin/branch.c
+++ b/builtin/branch.c

@@ -559,7 +559,7 @@ static int replace_each_worktree_head_symref(struct worktree **worktrees,
  			continue;
  
  		refs = get_worktree_ref_store(worktrees[i]);
-		if (refs_update_symref(refs, "HEAD", newref, logmsg))
+		if (refs_update_symref(refs, "HEAD", newref, logmsg, NULL))
  			ret = error(_("HEAD of working tree %s is not updated"),
  				    worktrees[i]->path);
  	}

diff --git a/builtin/checkout.c b/builtin/checkout.c
index 9c30000d3a..356ee9bcde 100644
--- a/builtin/checkout.c
+++ b/builtin/checkout.c

@@ -1015,7 +1015,7 @@ static void update_refs_for_switch(const struct checkout_opts *opts,
  			describe_detached_head(_("HEAD is now at"), new_branch_info->commit);
  		}
  	} else if (new_branch_info->path) {	/* Switch branches. */
-		if (refs_update_symref(get_main_ref_store(the_repository), "HEAD", new_branch_info->path, msg.buf) < 0)
+		if (refs_update_symref(get_main_ref_store(the_repository), "HEAD", new_branch_info->path, msg.buf, NULL) < 0)
  			die(_("unable to update HEAD"));
  		if (!opts->quiet) {
  			if (old_branch_info->path && !strcmp(new_branch_info->path, old_branch_info->path)) {

@@ -1479,7 +1479,7 @@ static int switch_unborn_to_new_branch(const struct checkout_opts *opts)
  		die(_("You are on a branch yet to be born"));
  	strbuf_addf(&branch_ref, "refs/heads/%s", opts->new_branch);
  	status = refs_update_symref(get_main_ref_store(the_repository),
-				    "HEAD", branch_ref.buf, "checkout -b");
+				    "HEAD", branch_ref.buf, "checkout -b", NULL);
  	strbuf_release(&branch_ref);
  	if (!opts->quiet)
  		fprintf(stderr, _("Switched to a new branch '%s'\n"),

diff --git a/builtin/clone.c b/builtin/clone.c
index e77339c847..ead2af20ea 100644
--- a/builtin/clone.c
+++ b/builtin/clone.c

@@ -661,7 +661,7 @@ static void update_remote_refs(const struct ref *refs,
  		strbuf_addstr(&head_ref, "HEAD");
  		if (refs_update_symref(get_main_ref_store(the_repository), head_ref.buf,
  				       remote_head_points_at->peer_ref->name,
-				       msg) < 0)
+				       msg, NULL) < 0)
  			die(_("unable to update %s"), head_ref.buf);
  		strbuf_release(&head_ref);
  	}

@@ -673,7 +673,7 @@ static void update_head(const struct ref *our, const struct ref *remote,
  	const char *head;
  	if (our && skip_prefix(our->name, "refs/heads/", &head)) {
  		/* Local default branch link */
-		if (refs_update_symref(get_main_ref_store(the_repository), "HEAD", our->name, NULL) < 0)
+		if (refs_update_symref(get_main_ref_store(the_repository), "HEAD", our->name, NULL, NULL) < 0)
  			die(_("unable to update HEAD"));
  		if (!option_bare) {
  			refs_update_ref(get_main_ref_store(the_repository),

@@ -702,7 +702,7 @@ static void update_head(const struct ref *our, const struct ref *remote,
  		 * Unborn head from remote; same as "our" case above except
  		 * that we have no ref to update.
  		 */
-		if (refs_update_symref(get_main_ref_store(the_repository), "HEAD", unborn, NULL) < 0)
+		if (refs_update_symref(get_main_ref_store(the_repository), "HEAD", unborn, NULL, NULL) < 0)
  			die(_("unable to update HEAD"));
  		if (!option_bare)
  			install_branch_config(0, head, remote_name, unborn);

diff --git a/builtin/notes.c b/builtin/notes.c
index 8c26e45526..ba646f06ff 100644
--- a/builtin/notes.c
+++ b/builtin/notes.c

@@ -980,7 +980,7 @@ static int merge(int argc, const char **argv, const char *prefix)
  			die(_("a notes merge into %s is already in-progress at %s"),
  			    notes_ref, wt->path);
  		free_worktrees(worktrees);
-		if (refs_update_symref(get_main_ref_store(the_repository), "NOTES_MERGE_REF", notes_ref, NULL))
+		if (refs_update_symref(get_main_ref_store(the_repository), "NOTES_MERGE_REF", notes_ref, NULL, NULL))
  			die(_("failed to store link to current notes ref (%s)"),
  			    notes_ref);
  		fprintf(stderr, _("Automatic notes merge failed. Fix conflicts in %s "

diff --git a/builtin/remote.c b/builtin/remote.c
index 76670ddd8b..d8ff440027 100644
--- a/builtin/remote.c
+++ b/builtin/remote.c

@@ -244,7 +244,7 @@ static int add(int argc, const char **argv, const char *prefix)
  		strbuf_reset(&buf2);
  		strbuf_addf(&buf2, "refs/remotes/%s/%s", name, master);
  
-		if (refs_update_symref(get_main_ref_store(the_repository), buf.buf, buf2.buf, "remote add"))
+		if (refs_update_symref(get_main_ref_store(the_repository), buf.buf, buf2.buf, "remote add", NULL))
  			result = error(_("Could not setup master '%s'"), master);
  	}
  

@@ -864,7 +864,7 @@ static int mv(int argc, const char **argv, const char *prefix)
  		strbuf_reset(&buf3);
  		strbuf_addf(&buf3, "remote: renamed %s to %s",
  				item->string, buf.buf);
-		if (refs_update_symref(get_main_ref_store(the_repository), buf.buf, buf2.buf, buf3.buf))
+		if (refs_update_symref(get_main_ref_store(the_repository), buf.buf, buf2.buf, buf3.buf, NULL))
  			die(_("creating '%s' failed"), buf.buf);
  		display_progress(progress, ++refs_renamed_nr);
  	}

@@ -1444,7 +1444,7 @@ static int set_head(int argc, const char **argv, const char *prefix)
  		/* make sure it's valid */
  		if (!refs_ref_exists(get_main_ref_store(the_repository), buf2.buf))
  			result |= error(_("Not a valid ref: %s"), buf2.buf);
-		else if (refs_update_symref(get_main_ref_store(the_repository), buf.buf, buf2.buf, "remote set-head"))
+		else if (refs_update_symref(get_main_ref_store(the_repository), buf.buf, buf2.buf, "remote set-head", NULL))
  			result |= error(_("Could not setup %s"), buf.buf);
  		else if (opt_a)
  			printf("%s/HEAD set to %s\n", argv[0], head_name);

diff --git a/builtin/symbolic-ref.c b/builtin/symbolic-ref.c
index 299d23d76a..7728fbc3c1 100644
--- a/builtin/symbolic-ref.c
+++ b/builtin/symbolic-ref.c

@@ -88,7 +88,7 @@ int cmd_symbolic_ref(int argc,
  		if (check_refname_format(argv[1], REFNAME_ALLOW_ONELEVEL) < 0)
  			die("Refusing to set '%s' to invalid ref '%s'", argv[0], argv[1]);
  		ret = !!refs_update_symref(get_main_ref_store(the_repository),
-					   argv[0], argv[1], msg);
+					   argv[0], argv[1], msg, NULL);
  		break;
  	default:
  		usage_with_options(git_symbolic_ref_usage, options);

diff --git a/builtin/worktree.c b/builtin/worktree.c
index fc31d072a6..a7ab4193c1 100644
--- a/builtin/worktree.c
+++ b/builtin/worktree.c

@@ -517,7 +517,7 @@ static int add_worktree(const char *path, const char *refname,
  		ret = refs_update_ref(wt_refs, NULL, "HEAD", &commit->object.oid,
  				      NULL, 0, UPDATE_REFS_MSG_ON_ERR);
  	else
-		ret = refs_update_symref(wt_refs, "HEAD", symref.buf, NULL);
+		ret = refs_update_symref(wt_refs, "HEAD", symref.buf, NULL, NULL);
  	if (ret)
  		goto done;
  

diff --git a/refs.c b/refs.c
index 5f729ed412..b964ac44d0 100644
--- a/refs.c
+++ b/refs.c

@@ -2114,7 +2114,8 @@ int peel_iterated_oid(struct repository *r, const struct object_id *base, struct
  }
  
  int refs_update_symref(struct ref_store *refs, const char *ref,
-		       const char *target, const char *logmsg)
+		       const char *target, const char *logmsg,
+		       struct strbuf *referent)
  {
  	struct ref_transaction *transaction;
  	struct strbuf err = STRBUF_INIT;

@@ -2122,17 +2123,23 @@ int refs_update_symref(struct ref_store *refs, const char *ref,
  
  	transaction = ref_store_transaction_begin(refs, &err);
  	if (!transaction ||
-	    ref_transaction_update(transaction, ref, NULL, NULL,
+		ref_transaction_update(transaction, ref, NULL, NULL,
  				   target, NULL, REF_NO_DEREF,
  				   logmsg, &err) ||
-	    ref_transaction_commit(transaction, &err)) {
+		ref_transaction_prepare(transaction, &err)) {
  		ret = error("%s", err.buf);
+		goto cleanup;
  	}
+	if (referent)
+		refs_read_symbolic_ref(refs, ref, referent);
+
+	if (ref_transaction_commit(transaction, &err))
+		ret = error("%s", err.buf);
  
+cleanup:
  	strbuf_release(&err);
  	if (transaction)
  		ref_transaction_free(transaction);
-
  	return ret;
  }
  

@@ -2948,4 +2955,3 @@ int ref_update_expects_existing_old_ref(struct ref_update *update)
  	return (update->flags & REF_HAVE_OLD) &&
  		(!is_null_oid(&update->old_oid) || update->old_target);
  }
-

diff --git a/refs.h b/refs.h
index 108dfc93b3..b09a3a4384 100644
--- a/refs.h
+++ b/refs.h

@@ -571,7 +571,8 @@ int refs_copy_existing_ref(struct ref_store *refs, const char *oldref,
  		    const char *newref, const char *logmsg);
  
  int refs_update_symref(struct ref_store *refs, const char *refname,
-		       const char *target, const char *logmsg);
+		       const char *target, const char *logmsg,
+		       struct strbuf *referent);
  
  enum action_on_err {
  	UPDATE_REFS_MSG_ON_ERR,

diff --git a/reset.c b/reset.c
index b22b1be792..cc36a9ed56 100644
--- a/reset.c
+++ b/reset.c

@@ -76,7 +76,7 @@ static int update_refs(const struct reset_head_opts *opts,
  		if (!ret)
  			ret = refs_update_symref(get_main_ref_store(the_repository),
  						 "HEAD", switch_to_branch,
-						 reflog_head);
+						 reflog_head, NULL);
  	}
  	if (!ret && run_hook)
  		run_hooks_l(the_repository, "post-checkout",

diff --git a/sequencer.c b/sequencer.c
index 8d01cd50ac..23b162924c 100644
--- a/sequencer.c
+++ b/sequencer.c

@@ -5107,7 +5107,7 @@ static int pick_commits(struct repository *r,
  			}
  			msg = reflog_message(opts, "finish", "returning to %s",
  				head_ref.buf);
-			if (refs_update_symref(get_main_ref_store(the_repository), "HEAD", head_ref.buf, msg)) {
+			if (refs_update_symref(get_main_ref_store(the_repository), "HEAD", head_ref.buf, msg, NULL)) {
  				res = error(_("could not update HEAD to %s"),
  					head_ref.buf);
  				goto cleanup_head_ref;

diff --git a/setup.c b/setup.c
index 94e79b2e48..d95f051465 100644
--- a/setup.c
+++ b/setup.c

@@ -2275,7 +2275,7 @@ void create_reference_database(enum ref_storage_format ref_storage_format,
  			die(_("invalid initial branch name: '%s'"),
  			    initial_branch);
  
-		if (refs_update_symref(get_main_ref_store(the_repository), "HEAD", ref, NULL) < 0)
+		if (refs_update_symref(get_main_ref_store(the_repository), "HEAD", ref, NULL, NULL) < 0)
  			exit(1);
  		free(ref);
  	}

diff --git a/t/helper/test-ref-store.c b/t/helper/test-ref-store.c
index 65346dee55..a911302bea 100644
--- a/t/helper/test-ref-store.c
+++ b/t/helper/test-ref-store.c

@@ -120,7 +120,7 @@ static int cmd_create_symref(struct ref_store *refs, const char **argv)
  	const char *target = notnull(*argv++, "target");
  	const char *logmsg = *argv++;
  
-	return refs_update_symref(refs, refname, target, logmsg);
+	return refs_update_symref(refs, refname, target, logmsg, NULL);
  }
  
  static struct flag_definition transaction_flags[] = {