diff --git a/.gitignore b/.gitignore
index 78a45cb5bec991..24635cf2d6f4a3 100644
--- a/.gitignore
+++ b/.gitignore
@@ -79,6 +79,7 @@
 /git-grep
 /git-hash-object
 /git-help
+/git-history
 /git-hook
 /git-http-backend
 /git-http-fetch
diff --git a/Documentation/RelNotes/2.54.0.adoc b/Documentation/RelNotes/2.54.0.adoc
index 20c660d82a40cf..59bb58e449b165 100644
--- a/Documentation/RelNotes/2.54.0.adoc
+++ b/Documentation/RelNotes/2.54.0.adoc
@@ -7,6 +7,17 @@ UI, Workflows & Features
  * "git add -p" and friends note what the current status of the hunk
    being shown is.
 
+ * "git history" history rewriting (experimental) command has been
+   added.
+
+
+ * "git replay" is taught to drop commits that become empty (not the
+   ones that are empty in the original).
+
+ * The help text and the documentation for the "--expire" option of
+   "git worktree [list|prune]" have been improved.
+
+
 
 Performance, Internal Implementation, Development Support etc.
 --------------------------------------------------------------
@@ -15,6 +26,11 @@ Performance, Internal Implementation, Development Support etc.
    each other by encoding submodule names before using them as path
    components.
 
+ * The string_list API gains a new helper, string_list_sort_u(), and
+   new unit tests to extend coverage.
+
+ * Improve set-up time of a perf test.
+
 
 Fixes since v2.53
 -----------------
@@ -31,6 +47,11 @@ Fixes since v2.53
    "-z") in the "git last-modified" command have been updated.
    (merge 9dcc09bed1 tc/last-modified-options-cleanup later to maint).
 
+ * A handful of code paths that started using batched ref update API
+   (after Git 2.51 or so) lost detailed error output, which have been
+   corrected.
+   (merge eff9299eac kn/ref-batch-output-error-reporting-fix later to maint).
+
  * Other code cleanup, docfix, build fix, etc.
    (merge d79fff4a11 jk/remote-tracking-ref-leakfix later to maint).
    (merge 7a747f972d dd/t5403-modernise later to maint).
diff --git a/Documentation/git-history.adoc b/Documentation/git-history.adoc
new file mode 100644
index 00000000000000..154e262b76a698
--- /dev/null
+++ b/Documentation/git-history.adoc
@@ -0,0 +1,73 @@
+git-history(1)
+==============
+
+NAME
+----
+git-history - EXPERIMENTAL: Rewrite history
+
+SYNOPSIS
+--------
+[synopsis]
+git history reword <commit> [--ref-action=(branches|head|print)]
+
+DESCRIPTION
+-----------
+
+Rewrite history by rearranging or modifying specific commits in the
+history.
+
+THIS COMMAND IS EXPERIMENTAL. THE BEHAVIOR MAY CHANGE.
+
+This command is related to linkgit:git-rebase[1] in that both commands can be
+used to rewrite history. There are a couple of major differences though:
+
+* linkgit:git-history[1] can work in a bare repository as it does not need to
+  touch either the index or the worktree.
+* linkgit:git-history[1] does not execute any linkgit:githooks[5] at the
+  current point in time. This may change in the future.
+* linkgit:git-history[1] by default updates all branches that are descendants
+  of the original commit to point to the rewritten commit.
+
+Overall, linkgit:git-history[1] aims to provide a more opinionated way to modify
+your commit history that is simpler to use compared to linkgit:git-rebase[1] in
+general.
+
+Use linkgit:git-rebase[1] if you want to reapply a range of commits onto a
+different base, or interactive rebases if you want to edit a range of commits
+at once.
+
+LIMITATIONS
+-----------
+
+This command does not (yet) work with histories that contain merges. You
+should use linkgit:git-rebase[1] with the `--rebase-merges` flag instead.
+
+Furthermore, the command does not support operations that can result in merge
+conflicts. This limitation is by design as history rewrites are not intended to
+be stateful operations. The limitation can be lifted once (if) Git learns about
+first-class conflicts.
+
+COMMANDS
+--------
+
+The following commands are available to rewrite history in different ways:
+
+`reword <commit>`::
+	Rewrite the commit message of the specified commit. All the other
+	details of this commit remain unchanged. This command will spawn an
+	editor with the current message of that commit.
+
+OPTIONS
+-------
+
+`--ref-action=(branches|head|print)`::
+	Control which references will be updated by the command, if any. With
+	`branches`, all local branches that point to commits which are
+	descendants of the original commit will be rewritten. With `head`, only
+	the current `HEAD` reference will be rewritten. With `print`, all
+	updates as they would be performed with `branches` are printed in a
+	format that can be consumed by linkgit:git-update-ref[1].
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/Documentation/git-replay.adoc b/Documentation/git-replay.adoc
index c3b214ec6964c7..8d696ce3abb491 100644
--- a/Documentation/git-replay.adoc
+++ b/Documentation/git-replay.adoc
@@ -62,7 +62,9 @@ The default mode can be configured via the `replay.refAction` configuration vari
 	Range of commits to replay; see "Specifying Ranges" in
 	linkgit:git-rev-parse[1]. In `--advance <branch>` mode, the
 	range should have a single tip, so that it's clear to which tip the
-	advanced <branch> should point.
+	advanced <branch> should point. Any commits in the range whose
+	changes are already present in the branch the commits are being
+	replayed onto will be dropped.
 
 :git-replay: 1
 include::rev-list-options.adoc[]
diff --git a/Documentation/git-worktree.adoc b/Documentation/git-worktree.adoc
index d74ad7b0e9bd75..fbf8426cd974e4 100644
--- a/Documentation/git-worktree.adoc
+++ b/Documentation/git-worktree.adoc
@@ -131,7 +131,13 @@ with linked worktrees if you move the main worktree manually.)
 
 `prune`::
 
-Prune worktree information in `$GIT_DIR/worktrees`.
+Remove worktree information in `$GIT_DIR/worktrees` for worktrees
+whose working trees are missing.  Useful after manually removing
+a working tree that is no longer needed (but use "git worktree
+remove" next time you want to do so).  Also, if you _moved_ a
+working tree elsewhere causing the worktree information to become
+dangling, see "git worktree repair" to reconnect the worktree to
+the new working tree location.
 
 `remove`::
 
@@ -271,7 +277,7 @@ mismatch, even if the links are correct.
 With `list`, output additional information about worktrees (see below).
 
 `--expire <time>`::
-	With `prune`, only expire unused worktrees older than _<time>_.
+	With `prune`, only prune missing worktrees if older than _<time>_.
 +
 With `list`, annotate missing worktrees as prunable if they are older than
 _<time>_.
diff --git a/Documentation/meson.build b/Documentation/meson.build
index f02dbc20cbcb86..fd2e8cc02d689f 100644
--- a/Documentation/meson.build
+++ b/Documentation/meson.build
@@ -64,6 +64,7 @@ manpages = {
   'git-gui.adoc' : 1,
   'git-hash-object.adoc' : 1,
   'git-help.adoc' : 1,
+  'git-history.adoc' : 1,
   'git-hook.adoc' : 1,
   'git-http-backend.adoc' : 1,
   'git-http-fetch.adoc' : 1,
diff --git a/Makefile b/Makefile
index 8aa489f3b6812f..4ac44331ea1ec0 100644
--- a/Makefile
+++ b/Makefile
@@ -1285,6 +1285,7 @@ LIB_OBJS += repack-geometry.o
 LIB_OBJS += repack-midx.o
 LIB_OBJS += repack-promisor.o
 LIB_OBJS += replace-object.o
+LIB_OBJS += replay.o
 LIB_OBJS += repo-settings.o
 LIB_OBJS += repository.o
 LIB_OBJS += rerere.o
@@ -1417,6 +1418,7 @@ BUILTIN_OBJS += builtin/get-tar-commit-id.o
 BUILTIN_OBJS += builtin/grep.o
 BUILTIN_OBJS += builtin/hash-object.o
 BUILTIN_OBJS += builtin/help.o
+BUILTIN_OBJS += builtin/history.o
 BUILTIN_OBJS += builtin/hook.o
 BUILTIN_OBJS += builtin/index-pack.o
 BUILTIN_OBJS += builtin/init-db.o
diff --git a/builtin.h b/builtin.h
index e5e16ecaa6c9d7..235c51f30e5380 100644
--- a/builtin.h
+++ b/builtin.h
@@ -196,6 +196,7 @@ int cmd_get_tar_commit_id(int argc, const char **argv, const char *prefix, struc
 int cmd_grep(int argc, const char **argv, const char *prefix, struct repository *repo);
 int cmd_hash_object(int argc, const char **argv, const char *prefix, struct repository *repo);
 int cmd_help(int argc, const char **argv, const char *prefix, struct repository *repo);
+int cmd_history(int argc, const char **argv, const char *prefix, struct repository *repo);
 int cmd_hook(int argc, const char **argv, const char *prefix, struct repository *repo);
 int cmd_index_pack(int argc, const char **argv, const char *prefix, struct repository *repo);
 int cmd_init_db(int argc, const char **argv, const char *prefix, struct repository *repo);
diff --git a/builtin/clone.c b/builtin/clone.c
index b40cee596804f5..b14a39a687c840 100644
--- a/builtin/clone.c
+++ b/builtin/clone.c
@@ -1136,8 +1136,7 @@ int cmd_clone(int argc,
 		int val;
 
 		/* remove duplicates */
-		string_list_sort(&option_recurse_submodules);
-		string_list_remove_duplicates(&option_recurse_submodules, 0);
+		string_list_sort_u(&option_recurse_submodules, 0);
 
 		/*
 		 * NEEDSWORK: In a multi-working-tree world, this needs to be
diff --git a/builtin/fast-export.c b/builtin/fast-export.c
index b90da5e616e0ef..0c5d2386d81b92 100644
--- a/builtin/fast-export.c
+++ b/builtin/fast-export.c
@@ -1118,8 +1118,7 @@ static void get_tags_and_duplicates(struct rev_cmdline_info *info)
 			free(full_name);
 	}
 
-	string_list_sort(&extra_refs);
-	string_list_remove_duplicates(&extra_refs, 0);
+	string_list_sort_u(&extra_refs, 0);
 }
 
 static void handle_tags_and_duplicates(struct string_list *extras)
diff --git a/builtin/fetch.c b/builtin/fetch.c
index 288d3772eaeabe..a3bc7e9380b9b6 100644
--- a/builtin/fetch.c
+++ b/builtin/fetch.c
@@ -861,12 +861,87 @@ static void display_ref_update(struct display_state *display_state, char code,
 	fputs(display_state->buf.buf, f);
 }
 
+struct ref_update_display_info {
+	bool failed;
+	char success_code;
+	char fail_code;
+	char *summary;
+	char *fail_detail;
+	char *success_detail;
+	char *ref;
+	char *remote;
+	struct object_id old_oid;
+	struct object_id new_oid;
+};
+
+struct ref_update_display_info_array {
+	struct ref_update_display_info *info;
+	size_t alloc, nr;
+};
+
+static struct ref_update_display_info *ref_update_display_info_append(
+					   struct ref_update_display_info_array *array,
+					   char success_code,
+					   char fail_code,
+					   const char *summary,
+					   const char *success_detail,
+					   const char *fail_detail,
+					   const char *ref,
+					   const char *remote,
+					   const struct object_id *old_oid,
+					   const struct object_id *new_oid)
+{
+	struct ref_update_display_info *info;
+
+	ALLOC_GROW(array->info, array->nr + 1, array->alloc);
+	info = &array->info[array->nr++];
+
+	info->failed = false;
+	info->success_code = success_code;
+	info->fail_code = fail_code;
+	info->summary = xstrdup(summary);
+	info->success_detail = xstrdup_or_null(success_detail);
+	info->fail_detail = xstrdup_or_null(fail_detail);
+	info->remote = xstrdup(remote);
+	info->ref = xstrdup(ref);
+
+	oidcpy(&info->old_oid, old_oid);
+	oidcpy(&info->new_oid, new_oid);
+
+	return info;
+}
+
+static void ref_update_display_info_set_failed(struct ref_update_display_info *info)
+{
+	info->failed = true;
+}
+
+static void ref_update_display_info_free(struct ref_update_display_info *info)
+{
+	free(info->summary);
+	free(info->success_detail);
+	free(info->fail_detail);
+	free(info->remote);
+	free(info->ref);
+}
+
+static void ref_update_display_info_display(struct ref_update_display_info *info,
+					    struct display_state *display_state,
+					    int summary_width)
+{
+	display_ref_update(display_state,
+			   info->failed ? info->fail_code : info->success_code,
+			   info->summary,
+			   info->failed ? info->fail_detail : info->success_detail,
+			   info->remote, info->ref, &info->old_oid,
+			   &info->new_oid, summary_width);
+}
+
 static int update_local_ref(struct ref *ref,
 			    struct ref_transaction *transaction,
-			    struct display_state *display_state,
 			    const struct ref *remote_ref,
-			    int summary_width,
-			    const struct fetch_config *config)
+			    const struct fetch_config *config,
+			    struct ref_update_display_info_array *display_array)
 {
 	struct commit *current = NULL, *updated;
 	int fast_forward = 0;
@@ -877,41 +952,56 @@ static int update_local_ref(struct ref *ref,
 
 	if (oideq(&ref->old_oid, &ref->new_oid)) {
 		if (verbosity > 0)
-			display_ref_update(display_state, '=', _("[up to date]"), NULL,
-					   remote_ref->name, ref->name,
-					   &ref->old_oid, &ref->new_oid, summary_width);
+			ref_update_display_info_append(display_array, '=', '=',
+						       _("[up to date]"), NULL,
+						       NULL, ref->name,
+						       remote_ref->name, &ref->old_oid,
+						       &ref->new_oid);
 		return 0;
 	}
 
 	if (!update_head_ok &&
 	    !is_null_oid(&ref->old_oid) &&
 	    branch_checked_out(ref->name)) {
+		struct ref_update_display_info *info;
 		/*
 		 * If this is the head, and it's not okay to update
 		 * the head, and the old value of the head isn't empty...
 		 */
-		display_ref_update(display_state, '!', _("[rejected]"),
-				   _("can't fetch into checked-out branch"),
-				   remote_ref->name, ref->name,
-				   &ref->old_oid, &ref->new_oid, summary_width);
+		info = ref_update_display_info_append(display_array, '!', '!',
+						      _("[rejected]"), NULL,
+						      _("can't fetch into checked-out branch"),
+						      ref->name, remote_ref->name,
+						      &ref->old_oid, &ref->new_oid);
+		ref_update_display_info_set_failed(info);
 		return 1;
 	}
 
 	if (!is_null_oid(&ref->old_oid) &&
 	    starts_with(ref->name, "refs/tags/")) {
+		struct ref_update_display_info *info;
+
 		if (force || ref->force) {
 			int r;
+
 			r = s_update_ref("updating tag", ref, transaction, 0);
-			display_ref_update(display_state, r ? '!' : 't', _("[tag update]"),
-					   r ? _("unable to update local ref") : NULL,
-					   remote_ref->name, ref->name,
-					   &ref->old_oid, &ref->new_oid, summary_width);
+
+			info = ref_update_display_info_append(display_array, 't', '!',
+							      _("[tag update]"), NULL,
+							      _("unable to update local ref"),
+							      ref->name, remote_ref->name,
+							      &ref->old_oid, &ref->new_oid);
+			if (r)
+				ref_update_display_info_set_failed(info);
+
 			return r;
 		} else {
-			display_ref_update(display_state, '!', _("[rejected]"),
-					   _("would clobber existing tag"),
-					   remote_ref->name, ref->name,
-					   &ref->old_oid, &ref->new_oid, summary_width);
+			info = ref_update_display_info_append(display_array, '!', '!',
+							      _("[rejected]"), NULL,
+							      _("would clobber existing tag"),
+							      ref->name, remote_ref->name,
+							      &ref->old_oid, &ref->new_oid);
+			ref_update_display_info_set_failed(info);
 			return 1;
 		}
 	}
@@ -921,6 +1011,7 @@ static int update_local_ref(struct ref *ref,
 	updated = lookup_commit_reference_gently(the_repository,
 						 &ref->new_oid, 1);
 	if (!current || !updated) {
+		struct ref_update_display_info *info;
 		const char *msg;
 		const char *what;
 		int r;
@@ -941,10 +1032,15 @@ static int update_local_ref(struct ref *ref,
 		}
 
 		r = s_update_ref(msg, ref, transaction, 0);
-		display_ref_update(display_state, r ? '!' : '*', what,
-				   r ? _("unable to update local ref") : NULL,
-				   remote_ref->name, ref->name,
-				   &ref->old_oid, &ref->new_oid, summary_width);
+
+		info = ref_update_display_info_append(display_array, '*', '!',
+						      what, NULL,
+						      _("unable to update local ref"),
+						      ref->name, remote_ref->name,
+						      &ref->old_oid, &ref->new_oid);
+		if (r)
+			ref_update_display_info_set_failed(info);
+
 		return r;
 	}
 
@@ -960,6 +1056,7 @@ static int update_local_ref(struct ref *ref,
 	}
 
 	if (fast_forward) {
+		struct ref_update_display_info *info;
 		struct strbuf quickref = STRBUF_INIT;
 		int r;
 
@@ -967,29 +1064,46 @@ static int update_local_ref(struct ref *ref,
 		strbuf_addstr(&quickref, "..");
 		strbuf_add_unique_abbrev(&quickref, &ref->new_oid, DEFAULT_ABBREV);
 		r = s_update_ref("fast-forward", ref, transaction, 1);
-		display_ref_update(display_state, r ? '!' : ' ', quickref.buf,
-				   r ? _("unable to update local ref") : NULL,
-				   remote_ref->name, ref->name,
-				   &ref->old_oid, &ref->new_oid, summary_width);
+
+		info = ref_update_display_info_append(display_array, ' ', '!',
+						      quickref.buf, NULL,
+						      _("unable to update local ref"),
+						      ref->name, remote_ref->name,
+						      &ref->old_oid, &ref->new_oid);
+		if (r)
+			ref_update_display_info_set_failed(info);
+
 		strbuf_release(&quickref);
 		return r;
 	} else if (force || ref->force) {
+		struct ref_update_display_info *info;
 		struct strbuf quickref = STRBUF_INIT;
 		int r;
+
 		strbuf_add_unique_abbrev(&quickref, &current->object.oid, DEFAULT_ABBREV);
 		strbuf_addstr(&quickref, "...");
 		strbuf_add_unique_abbrev(&quickref, &ref->new_oid, DEFAULT_ABBREV);
 		r = s_update_ref("forced-update", ref, transaction, 1);
-		display_ref_update(display_state, r ? '!' : '+', quickref.buf,
-				   r ? _("unable to update local ref") : _("forced update"),
-				   remote_ref->name, ref->name,
-				   &ref->old_oid, &ref->new_oid, summary_width);
+
+		info = ref_update_display_info_append(display_array, '+', '!',
+						      quickref.buf, _("forced update"),
+						      _("unable to update local ref"),
+						      ref->name, remote_ref->name,
+						      &ref->old_oid, &ref->new_oid);
+
+		if (r)
+			ref_update_display_info_set_failed(info);
+
 		strbuf_release(&quickref);
 		return r;
 	} else {
-		display_ref_update(display_state, '!', _("[rejected]"), _("non-fast-forward"),
-				   remote_ref->name, ref->name,
-				   &ref->old_oid, &ref->new_oid, summary_width);
+		struct ref_update_display_info *info;
+		info = ref_update_display_info_append(display_array, '!', '!',
+						      _("[rejected]"), NULL,
+						      _("non-fast-forward"),
+						      ref->name, remote_ref->name,
+						      &ref->old_oid, &ref->new_oid);
+		ref_update_display_info_set_failed(info);
 		return 1;
 	}
 }
@@ -1103,17 +1217,14 @@ static int store_updated_refs(struct display_state *display_state,
 			      int connectivity_checked,
 			      struct ref_transaction *transaction, struct ref *ref_map,
 			      struct fetch_head *fetch_head,
-			      const struct fetch_config *config)
+			      const struct fetch_config *config,
+			      struct ref_update_display_info_array *display_array)
 {
 	int rc = 0;
 	struct strbuf note = STRBUF_INIT;
 	const char *what, *kind;
 	struct ref *rm;
 	int want_status;
-	int summary_width = 0;
-
-	if (verbosity >= 0)
-		summary_width = transport_summary_width(ref_map);
 
 	if (!connectivity_checked) {
 		struct check_connected_options opt = CHECK_CONNECTED_INIT;
@@ -1218,8 +1329,8 @@ static int store_updated_refs(struct display_state *display_state,
 					  display_state->url_len);
 
 			if (ref) {
-				rc |= update_local_ref(ref, transaction, display_state,
-						       rm, summary_width, config);
+				rc |= update_local_ref(ref, transaction, rm,
+						       config, display_array);
 				free(ref);
 			} else if (write_fetch_head || dry_run) {
 				/*
@@ -1227,12 +1338,12 @@ static int store_updated_refs(struct display_state *display_state,
 				 * would be written to FETCH_HEAD, if --dry-run
 				 * is set).
 				 */
-				display_ref_update(display_state, '*',
-						   *kind ? kind : "branch", NULL,
-						   rm->name,
-						   "FETCH_HEAD",
-						   &rm->new_oid, &rm->old_oid,
-						   summary_width);
+
+				ref_update_display_info_append(display_array, '*', '*',
+							       *kind ? kind : "branch",
+							       NULL, NULL, "FETCH_HEAD",
+							       rm->name, &rm->new_oid,
+							       &rm->old_oid);
 			}
 		}
 	}
@@ -1300,7 +1411,8 @@ static int fetch_and_consume_refs(struct display_state *display_state,
 				  struct ref_transaction *transaction,
 				  struct ref *ref_map,
 				  struct fetch_head *fetch_head,
-				  const struct fetch_config *config)
+				  const struct fetch_config *config,
+				  struct ref_update_display_info_array *display_array)
 {
 	int connectivity_checked = 1;
 	int ret;
@@ -1322,7 +1434,8 @@ static int fetch_and_consume_refs(struct display_state *display_state,
 
 	trace2_region_enter("fetch", "consume_refs", the_repository);
 	ret = store_updated_refs(display_state, connectivity_checked,
-				 transaction, ref_map, fetch_head, config);
+				 transaction, ref_map, fetch_head, config,
+				 display_array);
 	trace2_region_leave("fetch", "consume_refs", the_repository);
 
 out:
@@ -1493,7 +1606,8 @@ static int backfill_tags(struct display_state *display_state,
 			 struct ref_transaction *transaction,
 			 struct ref *ref_map,
 			 struct fetch_head *fetch_head,
-			 const struct fetch_config *config)
+			 const struct fetch_config *config,
+			 struct ref_update_display_info_array *display_array)
 {
 	int retcode, cannot_reuse;
 
@@ -1515,7 +1629,7 @@ static int backfill_tags(struct display_state *display_state,
 	transport_set_option(transport, TRANS_OPT_DEPTH, "0");
 	transport_set_option(transport, TRANS_OPT_DEEPEN_RELATIVE, NULL);
 	retcode = fetch_and_consume_refs(display_state, transport, transaction, ref_map,
-					 fetch_head, config);
+					 fetch_head, config, display_array);
 
 	if (gsecondary) {
 		transport_disconnect(gsecondary);
@@ -1641,6 +1755,7 @@ struct ref_rejection_data {
 	bool conflict_msg_shown;
 	bool case_sensitive_msg_shown;
 	const char *remote_name;
+	struct strmap *rejected_refs;
 };
 
 static void ref_transaction_rejection_handler(const char *refname,
@@ -1649,6 +1764,7 @@ static void ref_transaction_rejection_handler(const char *refname,
 					      const char *old_target UNUSED,
 					      const char *new_target UNUSED,
 					      enum ref_transaction_error err,
+					      const char *details,
 					      void *cb_data)
 {
 	struct ref_rejection_data *data = cb_data;
@@ -1673,11 +1789,14 @@ static void ref_transaction_rejection_handler(const char *refname,
 			"branches"), data->remote_name);
 		data->conflict_msg_shown = true;
 	} else {
-		const char *reason = ref_transaction_error_msg(err);
-
-		error(_("fetching ref %s failed: %s"), refname, reason);
+		if (details)
+			error("%s", details);
+		else
+			error(_("fetching ref %s failed: %s"),
+			      refname, ref_transaction_error_msg(err));
 	}
 
+	strmap_put(data->rejected_refs, refname, NULL);
 	*data->retcode = 1;
 }
 
@@ -1687,6 +1806,7 @@ static void ref_transaction_rejection_handler(const char *refname,
  */
 static int commit_ref_transaction(struct ref_transaction **transaction,
 				  bool is_atomic, const char *remote_name,
+				  struct strmap *rejected_refs,
 				  struct strbuf *err)
 {
 	int retcode = ref_transaction_commit(*transaction, err);
@@ -1698,6 +1818,7 @@ static int commit_ref_transaction(struct ref_transaction **transaction,
 			.conflict_msg_shown = 0,
 			.remote_name = remote_name,
 			.retcode = &retcode,
+			.rejected_refs = rejected_refs,
 		};
 
 		ref_transaction_for_each_rejected_update(*transaction,
@@ -1726,6 +1847,9 @@ static int do_fetch(struct transport *transport,
 	struct fetch_head fetch_head = { 0 };
 	struct strbuf err = STRBUF_INIT;
 	int do_set_head = 0;
+	struct ref_update_display_info_array display_array = { 0 };
+	struct strmap rejected_refs = STRMAP_INIT;
+	int summary_width = 0;
 
 	if (tags == TAGS_DEFAULT) {
 		if (transport->remote->fetch_tags == 2)
@@ -1850,7 +1974,7 @@ static int do_fetch(struct transport *transport,
 	}
 
 	if (fetch_and_consume_refs(&display_state, transport, transaction, ref_map,
-				   &fetch_head, config)) {
+				   &fetch_head, config, &display_array)) {
 		retcode = 1;
 		goto cleanup;
 	}
@@ -1873,7 +1997,7 @@ static int do_fetch(struct transport *transport,
 			 * the transaction and don't commit anything.
 			 */
 			if (backfill_tags(&display_state, transport, transaction, tags_ref_map,
-					  &fetch_head, config))
+					  &fetch_head, config, &display_array))
 				retcode = 1;
 		}
 
@@ -1883,8 +2007,12 @@ static int do_fetch(struct transport *transport,
 	if (retcode)
 		goto cleanup;
 
+	if (verbosity >= 0)
+		summary_width = transport_summary_width(ref_map);
+
 	retcode = commit_ref_transaction(&transaction, atomic_fetch,
-					 transport->remote->name, &err);
+					 transport->remote->name,
+					 &rejected_refs, &err);
 	/*
 	 * With '--atomic', bail out if the transaction fails. Without '--atomic',
 	 * continue to fetch head and perform other post-fetch operations.
@@ -1962,7 +2090,17 @@ static int do_fetch(struct transport *transport,
 	 */
 	if (retcode && !atomic_fetch && transaction)
 		commit_ref_transaction(&transaction, false,
-				       transport->remote->name, &err);
+				       transport->remote->name,
+				       &rejected_refs, &err);
+
+	for (size_t i = 0; i < display_array.nr; i++) {
+		struct ref_update_display_info *info = &display_array.info[i];
+
+		if (!info->failed && strmap_contains(&rejected_refs, info->ref))
+			ref_update_display_info_set_failed(info);
+		ref_update_display_info_display(info, &display_state, summary_width);
+		ref_update_display_info_free(info);
+	}
 
 	if (retcode) {
 		if (err.len) {
@@ -1977,6 +2115,9 @@ static int do_fetch(struct transport *transport,
 
 	if (transaction)
 		ref_transaction_free(transaction);
+
+	free(display_array.info);
+	strmap_clear(&rejected_refs, 0);
 	display_state_release(&display_state);
 	close_fetch_head(&fetch_head);
 	strbuf_release(&err);
diff --git a/builtin/history.c b/builtin/history.c
new file mode 100644
index 00000000000000..8dcb9a604665f8
--- /dev/null
+++ b/builtin/history.c
@@ -0,0 +1,427 @@
+#define USE_THE_REPOSITORY_VARIABLE
+
+#include "builtin.h"
+#include "commit.h"
+#include "commit-reach.h"
+#include "config.h"
+#include "editor.h"
+#include "environment.h"
+#include "gettext.h"
+#include "hex.h"
+#include "parse-options.h"
+#include "refs.h"
+#include "replay.h"
+#include "revision.h"
+#include "sequencer.h"
+#include "strvec.h"
+#include "tree.h"
+#include "wt-status.h"
+
+#define GIT_HISTORY_REWORD_USAGE \
+	N_("git history reword <commit> [--ref-action=(branches|head|print)]")
+
+static void change_data_free(void *util, const char *str UNUSED)
+{
+	struct wt_status_change_data *d = util;
+	free(d->rename_source);
+	free(d);
+}
+
+static int fill_commit_message(struct repository *repo,
+			       const struct object_id *old_tree,
+			       const struct object_id *new_tree,
+			       const char *default_message,
+			       const char *action,
+			       struct strbuf *out)
+{
+	const char *path = git_path_commit_editmsg();
+	const char *hint =
+		_("Please enter the commit message for the %s changes."
+		  " Lines starting\nwith '%s' will be ignored, and an"
+		  " empty message aborts the commit.\n");
+	struct wt_status s;
+
+	strbuf_addstr(out, default_message);
+	strbuf_addch(out, '\n');
+	strbuf_commented_addf(out, comment_line_str, hint, action, comment_line_str);
+	write_file_buf(path, out->buf, out->len);
+
+	wt_status_prepare(repo, &s);
+	FREE_AND_NULL(s.branch);
+	s.ahead_behind_flags = AHEAD_BEHIND_QUICK;
+	s.commit_template = 1;
+	s.colopts = 0;
+	s.display_comment_prefix = 1;
+	s.hints = 0;
+	s.use_color = 0;
+	s.whence = FROM_COMMIT;
+	s.committable = 1;
+
+	s.fp = fopen(git_path_commit_editmsg(), "a");
+	if (!s.fp)
+		return error_errno(_("could not open '%s'"), git_path_commit_editmsg());
+
+	wt_status_collect_changes_trees(&s, old_tree, new_tree);
+	wt_status_print(&s);
+	wt_status_collect_free_buffers(&s);
+	string_list_clear_func(&s.change, change_data_free);
+
+	strbuf_reset(out);
+	if (launch_editor(path, out, NULL)) {
+		fprintf(stderr, _("Aborting commit as launching the editor failed.\n"));
+		return -1;
+	}
+	strbuf_stripspace(out, comment_line_str);
+
+	cleanup_message(out, COMMIT_MSG_CLEANUP_ALL, 0);
+
+	if (!out->len) {
+		fprintf(stderr, _("Aborting commit due to empty commit message.\n"));
+		return -1;
+	}
+
+	return 0;
+}
+
+static int commit_tree_with_edited_message(struct repository *repo,
+					   const char *action,
+					   struct commit *original,
+					   struct commit **out)
+{
+	const char *exclude_gpgsig[] = {
+		/* We reencode the message, so the encoding needs to be stripped. */
+		"encoding",
+		/* We need to strip signatures as those will become invalid. */
+		"gpgsig",
+		"gpgsig-sha256",
+		NULL,
+	};
+	const char *original_message, *original_body, *ptr;
+	struct commit_extra_header *original_extra_headers = NULL;
+	struct strbuf commit_message = STRBUF_INIT;
+	struct object_id rewritten_commit_oid;
+	struct object_id original_tree_oid;
+	struct object_id parent_tree_oid;
+	char *original_author = NULL;
+	struct commit *parent;
+	size_t len;
+	int ret;
+
+	original_tree_oid = repo_get_commit_tree(repo, original)->object.oid;
+
+	parent = original->parents ? original->parents->item : NULL;
+	if (parent) {
+		if (repo_parse_commit(repo, parent)) {
+			ret = error(_("unable to parse parent commit %s"),
+				    oid_to_hex(&parent->object.oid));
+			goto out;
+		}
+
+		parent_tree_oid = repo_get_commit_tree(repo, parent)->object.oid;
+	} else {
+		oidcpy(&parent_tree_oid, repo->hash_algo->empty_tree);
+	}
+
+	/* We retain authorship of the original commit. */
+	original_message = repo_logmsg_reencode(repo, original, NULL, NULL);
+	ptr = find_commit_header(original_message, "author", &len);
+	if (ptr)
+		original_author = xmemdupz(ptr, len);
+	find_commit_subject(original_message, &original_body);
+
+	ret = fill_commit_message(repo, &parent_tree_oid, &original_tree_oid,
+				  original_body, action, &commit_message);
+	if (ret < 0)
+		goto out;
+
+	original_extra_headers = read_commit_extra_headers(original, exclude_gpgsig);
+
+	ret = commit_tree_extended(commit_message.buf, commit_message.len, &original_tree_oid,
+				   original->parents, &rewritten_commit_oid, original_author,
+				   NULL, NULL, original_extra_headers);
+	if (ret < 0)
+		goto out;
+
+	*out = lookup_commit_or_die(&rewritten_commit_oid, "rewritten commit");
+
+out:
+	free_commit_extra_headers(original_extra_headers);
+	strbuf_release(&commit_message);
+	free(original_author);
+	return ret;
+}
+
+enum ref_action {
+	REF_ACTION_DEFAULT,
+	REF_ACTION_BRANCHES,
+	REF_ACTION_HEAD,
+	REF_ACTION_PRINT,
+};
+
+static int parse_ref_action(const struct option *opt, const char *value, int unset)
+{
+	enum ref_action *action = opt->value;
+
+	BUG_ON_OPT_NEG_NOARG(unset, value);
+	if (!strcmp(value, "branches")) {
+		*action = REF_ACTION_BRANCHES;
+	} else if (!strcmp(value, "head")) {
+		*action = REF_ACTION_HEAD;
+	} else if (!strcmp(value, "print")) {
+		*action = REF_ACTION_PRINT;
+	} else {
+		return error(_("%s expects one of 'branches', 'head' or 'print'"),
+			     opt->long_name);
+	}
+
+	return 0;
+}
+
+static int handle_reference_updates(enum ref_action action,
+				    struct repository *repo,
+				    struct commit *original,
+				    struct commit *rewritten,
+				    const char *reflog_msg)
+{
+	const struct name_decoration *decoration;
+	struct replay_revisions_options opts = { 0 };
+	struct replay_result result = { 0 };
+	struct ref_transaction *transaction = NULL;
+	struct strvec args = STRVEC_INIT;
+	struct strbuf err = STRBUF_INIT;
+	struct commit *head = NULL;
+	struct rev_info revs;
+	char hex[GIT_MAX_HEXSZ + 1];
+	bool detached_head;
+	int head_flags = 0;
+	int ret;
+
+	refs_read_ref_full(get_main_ref_store(repo), "HEAD",
+			   RESOLVE_REF_NO_RECURSE, NULL, &head_flags);
+	detached_head = !(head_flags & REF_ISSYMREF);
+
+	repo_init_revisions(repo, &revs, NULL);
+	strvec_push(&args, "ignored");
+	strvec_push(&args, "--reverse");
+	strvec_push(&args, "--topo-order");
+	strvec_push(&args, "--full-history");
+
+	/* We only want to see commits that are descendants of the old commit. */
+	strvec_pushf(&args, "--ancestry-path=%s",
+		     oid_to_hex(&original->object.oid));
+
+	/*
+	 * Ancestry path may also show ancestors of the old commit, but we
+	 * don't want to see those, either.
+	 */
+	strvec_pushf(&args, "^%s", oid_to_hex(&original->object.oid));
+
+	/*
+	 * When we're asked to update HEAD we need to verify that the commit
+	 * that we want to rewrite is actually an ancestor of it and, if so,
+	 * update it. Otherwise we'll update (or print) all descendant
+	 * branches.
+	 */
+	if (action == REF_ACTION_HEAD) {
+		struct commit_list *from_list = NULL;
+
+		head = lookup_commit_reference_by_name("HEAD");
+		if (!head) {
+			ret = error(_("cannot look up HEAD"));
+			goto out;
+		}
+
+		commit_list_insert(original, &from_list);
+		ret = repo_is_descendant_of(repo, head, from_list);
+		free_commit_list(from_list);
+
+		if (ret < 0) {
+			ret = error(_("cannot determine descendance"));
+			goto out;
+		} else if (!ret) {
+			ret = error(_("rewritten commit must be an ancestor "
+				      "of HEAD when using --ref-action=head"));
+			goto out;
+		}
+
+		strvec_push(&args, "HEAD");
+	} else {
+		strvec_push(&args, "--branches");
+		strvec_push(&args, "HEAD");
+	}
+
+	setup_revisions_from_strvec(&args, &revs, NULL);
+	if (args.nr != 1)
+		BUG("revisions were set up with invalid argument");
+
+	opts.onto = oid_to_hex_r(hex, &rewritten->object.oid);
+
+	ret = replay_revisions(&revs, &opts, &result);
+	if (ret)
+		goto out;
+
+	switch (action) {
+	case REF_ACTION_BRANCHES:
+	case REF_ACTION_HEAD:
+		transaction = ref_store_transaction_begin(get_main_ref_store(repo), 0, &err);
+		if (!transaction) {
+			ret = error(_("failed to begin ref transaction: %s"), err.buf);
+			goto out;
+		}
+
+		for (size_t i = 0; i < result.updates_nr; i++) {
+			ret = ref_transaction_update(transaction,
+						     result.updates[i].refname,
+						     &result.updates[i].new_oid,
+						     &result.updates[i].old_oid,
+						     NULL, NULL, 0, reflog_msg, &err);
+			if (ret) {
+				ret = error(_("failed to update ref '%s': %s"),
+					    result.updates[i].refname, err.buf);
+				goto out;
+			}
+		}
+
+		/*
+		 * `replay_revisions()` only updates references that are
+		 * ancestors of `rewritten`, so we need to manually
+		 * handle updating references that point to `original`.
+		 */
+		for (decoration = get_name_decoration(&original->object);
+		     decoration;
+		     decoration = decoration->next)
+		{
+			if (decoration->type != DECORATION_REF_LOCAL &&
+			    decoration->type != DECORATION_REF_HEAD)
+				continue;
+
+			if (action == REF_ACTION_HEAD &&
+			    decoration->type != DECORATION_REF_HEAD)
+				continue;
+
+			/*
+			 * We only need to update HEAD separately in case it's
+			 * detached. If it's not we'd already update the branch
+			 * it is pointing to.
+			 */
+			if (action == REF_ACTION_BRANCHES &&
+			    decoration->type == DECORATION_REF_HEAD &&
+			    !detached_head)
+				continue;
+
+			ret = ref_transaction_update(transaction,
+						     decoration->name,
+						     &rewritten->object.oid,
+						     &original->object.oid,
+						     NULL, NULL, 0, reflog_msg, &err);
+			if (ret) {
+				ret = error(_("failed to update ref '%s': %s"),
+					    decoration->name, err.buf);
+				goto out;
+			}
+		}
+
+		if (ref_transaction_commit(transaction, &err)) {
+			ret = error(_("failed to commit ref transaction: %s"), err.buf);
+			goto out;
+		}
+
+		break;
+	case REF_ACTION_PRINT:
+		for (size_t i = 0; i < result.updates_nr; i++)
+			printf("update %s %s %s\n",
+			       result.updates[i].refname,
+			       oid_to_hex(&result.updates[i].new_oid),
+			       oid_to_hex(&result.updates[i].old_oid));
+		break;
+	default:
+		BUG("unsupported ref action %d", action);
+	}
+
+	ret = 0;
+
+out:
+	ref_transaction_free(transaction);
+	replay_result_release(&result);
+	release_revisions(&revs);
+	strbuf_release(&err);
+	strvec_clear(&args);
+	return ret;
+}
+
+static int cmd_history_reword(int argc,
+			      const char **argv,
+			      const char *prefix,
+			      struct repository *repo)
+{
+	const char * const usage[] = {
+		GIT_HISTORY_REWORD_USAGE,
+		NULL,
+	};
+	enum ref_action action = REF_ACTION_DEFAULT;
+	struct option options[] = {
+		OPT_CALLBACK_F(0, "ref-action", &action, N_("<action>"),
+			       N_("control ref update behavior (branches|head|print)"),
+			       PARSE_OPT_NONEG, parse_ref_action),
+		OPT_END(),
+	};
+	struct strbuf reflog_msg = STRBUF_INIT;
+	struct commit *original, *rewritten;
+	int ret;
+
+	argc = parse_options(argc, argv, prefix, options, usage, 0);
+	if (argc != 1) {
+		ret = error(_("command expects a single revision"));
+		goto out;
+	}
+	repo_config(repo, git_default_config, NULL);
+
+	if (action == REF_ACTION_DEFAULT)
+		action = REF_ACTION_BRANCHES;
+
+	original = lookup_commit_reference_by_name(argv[0]);
+	if (!original) {
+		ret = error(_("commit cannot be found: %s"), argv[0]);
+		goto out;
+	}
+
+	ret = commit_tree_with_edited_message(repo, "reworded", original, &rewritten);
+	if (ret < 0) {
+		ret = error(_("failed writing reworded commit"));
+		goto out;
+	}
+
+	strbuf_addf(&reflog_msg, "reword: updating %s", argv[0]);
+
+	ret = handle_reference_updates(action, repo, original, rewritten,
+				       reflog_msg.buf);
+	if (ret < 0) {
+		ret = error(_("failed replaying descendants"));
+		goto out;
+	}
+
+	ret = 0;
+
+out:
+	strbuf_release(&reflog_msg);
+	return ret;
+}
+
+int cmd_history(int argc,
+		const char **argv,
+		const char *prefix,
+		struct repository *repo)
+{
+	const char * const usage[] = {
+		GIT_HISTORY_REWORD_USAGE,
+		NULL,
+	};
+	parse_opt_subcommand_fn *fn = NULL;
+	struct option options[] = {
+		OPT_SUBCOMMAND("reword", &fn, cmd_history_reword),
+		OPT_END(),
+	};
+
+	argc = parse_options(argc, argv, prefix, options, usage, 0);
+	return fn(argc, argv, prefix, repo);
+}
diff --git a/builtin/pack-objects.c b/builtin/pack-objects.c
index 5846b6a293a27b..9807dd0eff0f6a 100644
--- a/builtin/pack-objects.c
+++ b/builtin/pack-objects.c
@@ -3855,10 +3855,8 @@ static void read_packs_list_from_stdin(struct rev_info *revs)
 		strbuf_reset(&buf);
 	}
 
-	string_list_sort(&include_packs);
-	string_list_remove_duplicates(&include_packs, 0);
-	string_list_sort(&exclude_packs);
-	string_list_remove_duplicates(&exclude_packs, 0);
+	string_list_sort_u(&include_packs, 0);
+	string_list_sort_u(&exclude_packs, 0);
 
 	repo_for_each_pack(the_repository, p) {
 		const char *pack_name = pack_basename(p);
diff --git a/builtin/receive-pack.c b/builtin/receive-pack.c
index 9c491746168a6f..d1aacf8b2a9b9e 100644
--- a/builtin/receive-pack.c
+++ b/builtin/receive-pack.c
@@ -1853,10 +1853,14 @@ static void ref_transaction_rejection_handler(const char *refname,
 					      const char *old_target UNUSED,
 					      const char *new_target UNUSED,
 					      enum ref_transaction_error err,
+					      const char *details,
 					      void *cb_data)
 {
 	struct strmap *failed_refs = cb_data;
 
+	if (details)
+		rp_error("%s", details);
+
 	strmap_put(failed_refs, refname, (char *)ref_transaction_error_msg(err));
 }
 
@@ -1923,6 +1927,7 @@ static void execute_commands_non_atomic(struct command *commands,
 		}
 
 		ref_transaction_for_each_rejected_update(transaction,
+
 							 ref_transaction_rejection_handler,
 							 &failed_refs);
 
@@ -1934,7 +1939,7 @@ static void execute_commands_non_atomic(struct command *commands,
 			if (reported_error)
 				cmd->error_string = reported_error;
 			else if (strmap_contains(&failed_refs, cmd->ref_name))
-				cmd->error_string = strmap_get(&failed_refs, cmd->ref_name);
+				cmd->error_string = cmd->error_string_owned = xstrdup(strmap_get(&failed_refs, cmd->ref_name));
 		}
 
 	cleanup:
diff --git a/builtin/replay.c b/builtin/replay.c
index 1960bbbee8685d..2cdde830a8a0f4 100644
--- a/builtin/replay.c
+++ b/builtin/replay.c
@@ -2,257 +2,22 @@
  * "git replay" builtin command
  */
 
-#define USE_THE_REPOSITORY_VARIABLE
-#define DISABLE_SIGN_COMPARE_WARNINGS
-
 #include "git-compat-util.h"
 
 #include "builtin.h"
 #include "config.h"
-#include "environment.h"
 #include "hex.h"
-#include "lockfile.h"
-#include "merge-ort.h"
 #include "object-name.h"
 #include "parse-options.h"
 #include "refs.h"
+#include "replay.h"
 #include "revision.h"
-#include "strmap.h"
-#include <oidset.h>
-#include <tree.h>
 
 enum ref_action_mode {
 	REF_ACTION_UPDATE,
 	REF_ACTION_PRINT,
 };
 
-static const char *short_commit_name(struct repository *repo,
-				     struct commit *commit)
-{
-	return repo_find_unique_abbrev(repo, &commit->object.oid,
-				       DEFAULT_ABBREV);
-}
-
-static struct commit *peel_committish(struct repository *repo,
-				      const char *name,
-				      const char *mode)
-{
-	struct object *obj;
-	struct object_id oid;
-
-	if (repo_get_oid(repo, name, &oid))
-		die(_("'%s' is not a valid commit-ish for %s"), name, mode);
-	obj = parse_object_or_die(repo, &oid, name);
-	return (struct commit *)repo_peel_to_type(repo, name, 0, obj,
-						  OBJ_COMMIT);
-}
-
-static char *get_author(const char *message)
-{
-	size_t len;
-	const char *a;
-
-	a = find_commit_header(message, "author", &len);
-	if (a)
-		return xmemdupz(a, len);
-
-	return NULL;
-}
-
-static struct commit *create_commit(struct repository *repo,
-				    struct tree *tree,
-				    struct commit *based_on,
-				    struct commit *parent)
-{
-	struct object_id ret;
-	struct object *obj = NULL;
-	struct commit_list *parents = NULL;
-	char *author;
-	char *sign_commit = NULL; /* FIXME: cli users might want to sign again */
-	struct commit_extra_header *extra = NULL;
-	struct strbuf msg = STRBUF_INIT;
-	const char *out_enc = get_commit_output_encoding();
-	const char *message = repo_logmsg_reencode(repo, based_on,
-						   NULL, out_enc);
-	const char *orig_message = NULL;
-	const char *exclude_gpgsig[] = { "gpgsig", "gpgsig-sha256", NULL };
-
-	commit_list_insert(parent, &parents);
-	extra = read_commit_extra_headers(based_on, exclude_gpgsig);
-	find_commit_subject(message, &orig_message);
-	strbuf_addstr(&msg, orig_message);
-	author = get_author(message);
-	reset_ident_date();
-	if (commit_tree_extended(msg.buf, msg.len, &tree->object.oid, parents,
-				 &ret, author, NULL, sign_commit, extra)) {
-		error(_("failed to write commit object"));
-		goto out;
-	}
-
-	obj = parse_object(repo, &ret);
-
-out:
-	repo_unuse_commit_buffer(the_repository, based_on, message);
-	free_commit_extra_headers(extra);
-	free_commit_list(parents);
-	strbuf_release(&msg);
-	free(author);
-	return (struct commit *)obj;
-}
-
-struct ref_info {
-	struct commit *onto;
-	struct strset positive_refs;
-	struct strset negative_refs;
-	int positive_refexprs;
-	int negative_refexprs;
-};
-
-static void get_ref_information(struct repository *repo,
-				struct rev_cmdline_info *cmd_info,
-				struct ref_info *ref_info)
-{
-	int i;
-
-	ref_info->onto = NULL;
-	strset_init(&ref_info->positive_refs);
-	strset_init(&ref_info->negative_refs);
-	ref_info->positive_refexprs = 0;
-	ref_info->negative_refexprs = 0;
-
-	/*
-	 * When the user specifies e.g.
-	 *   git replay origin/main..mybranch
-	 *   git replay ^origin/next mybranch1 mybranch2
-	 * we want to be able to determine where to replay the commits.  In
-	 * these examples, the branches are probably based on an old version
-	 * of either origin/main or origin/next, so we want to replay on the
-	 * newest version of that branch.  In contrast we would want to error
-	 * out if they ran
-	 *   git replay ^origin/master ^origin/next mybranch
-	 *   git replay mybranch~2..mybranch
-	 * the first of those because there's no unique base to choose, and
-	 * the second because they'd likely just be replaying commits on top
-	 * of the same commit and not making any difference.
-	 */
-	for (i = 0; i < cmd_info->nr; i++) {
-		struct rev_cmdline_entry *e = cmd_info->rev + i;
-		struct object_id oid;
-		const char *refexpr = e->name;
-		char *fullname = NULL;
-		int can_uniquely_dwim = 1;
-
-		if (*refexpr == '^')
-			refexpr++;
-		if (repo_dwim_ref(repo, refexpr, strlen(refexpr), &oid, &fullname, 0) != 1)
-			can_uniquely_dwim = 0;
-
-		if (e->flags & BOTTOM) {
-			if (can_uniquely_dwim)
-				strset_add(&ref_info->negative_refs, fullname);
-			if (!ref_info->negative_refexprs)
-				ref_info->onto = lookup_commit_reference_gently(repo,
-										&e->item->oid, 1);
-			ref_info->negative_refexprs++;
-		} else {
-			if (can_uniquely_dwim)
-				strset_add(&ref_info->positive_refs, fullname);
-			ref_info->positive_refexprs++;
-		}
-
-		free(fullname);
-	}
-}
-
-static void set_up_replay_mode(struct repository *repo,
-			       struct rev_cmdline_info *cmd_info,
-			       const char *onto_name,
-			       char **advance_name,
-			       struct commit **onto,
-			       struct strset **update_refs)
-{
-	struct ref_info rinfo;
-
-	get_ref_information(repo, cmd_info, &rinfo);
-	if (!rinfo.positive_refexprs)
-		die(_("need some commits to replay"));
-
-	die_for_incompatible_opt2(!!onto_name, "--onto",
-				  !!*advance_name, "--advance");
-	if (onto_name) {
-		*onto = peel_committish(repo, onto_name, "--onto");
-		if (rinfo.positive_refexprs <
-		    strset_get_size(&rinfo.positive_refs))
-			die(_("all positive revisions given must be references"));
-		*update_refs = xcalloc(1, sizeof(**update_refs));
-		**update_refs = rinfo.positive_refs;
-		memset(&rinfo.positive_refs, 0, sizeof(**update_refs));
-	} else {
-		struct object_id oid;
-		char *fullname = NULL;
-
-		if (!*advance_name)
-			BUG("expected either onto_name or *advance_name in this function");
-
-		if (repo_dwim_ref(repo, *advance_name, strlen(*advance_name),
-			     &oid, &fullname, 0) == 1) {
-			free(*advance_name);
-			*advance_name = fullname;
-		} else {
-			die(_("argument to --advance must be a reference"));
-		}
-		*onto = peel_committish(repo, *advance_name, "--advance");
-		if (rinfo.positive_refexprs > 1)
-			die(_("cannot advance target with multiple sources because ordering would be ill-defined"));
-	}
-	strset_clear(&rinfo.negative_refs);
-	strset_clear(&rinfo.positive_refs);
-}
-
-static struct commit *mapped_commit(kh_oid_map_t *replayed_commits,
-				    struct commit *commit,
-				    struct commit *fallback)
-{
-	khint_t pos = kh_get_oid_map(replayed_commits, commit->object.oid);
-	if (pos == kh_end(replayed_commits))
-		return fallback;
-	return kh_value(replayed_commits, pos);
-}
-
-static struct commit *pick_regular_commit(struct repository *repo,
-					  struct commit *pickme,
-					  kh_oid_map_t *replayed_commits,
-					  struct commit *onto,
-					  struct merge_options *merge_opt,
-					  struct merge_result *result)
-{
-	struct commit *base, *replayed_base;
-	struct tree *pickme_tree, *base_tree;
-
-	base = pickme->parents->item;
-	replayed_base = mapped_commit(replayed_commits, base, onto);
-
-	result->tree = repo_get_commit_tree(repo, replayed_base);
-	pickme_tree = repo_get_commit_tree(repo, pickme);
-	base_tree = repo_get_commit_tree(repo, base);
-
-	merge_opt->branch1 = short_commit_name(repo, replayed_base);
-	merge_opt->branch2 = short_commit_name(repo, pickme);
-	merge_opt->ancestor = xstrfmt("parent of %s", merge_opt->branch2);
-
-	merge_incore_nonrecursive(merge_opt,
-				  base_tree,
-				  result->tree,
-				  pickme_tree,
-				  result);
-
-	free((char*)merge_opt->ancestor);
-	merge_opt->ancestor = NULL;
-	if (!result->clean)
-		return NULL;
-	return create_commit(repo, result->tree, pickme, replayed_base);
-}
-
 static enum ref_action_mode parse_ref_action_mode(const char *ref_action, const char *source)
 {
 	if (!ref_action || !strcmp(ref_action, "update"))
@@ -306,21 +71,11 @@ int cmd_replay(int argc,
 	       const char *prefix,
 	       struct repository *repo)
 {
-	const char *advance_name_opt = NULL;
-	char *advance_name = NULL;
-	struct commit *onto = NULL;
-	const char *onto_name = NULL;
-	int contained = 0;
+	struct replay_revisions_options opts = { 0 };
+	struct replay_result result = { 0 };
 	const char *ref_action = NULL;
 	enum ref_action_mode ref_mode;
-
 	struct rev_info revs;
-	struct commit *last_commit = NULL;
-	struct commit *commit;
-	struct merge_options merge_opt;
-	struct merge_result result;
-	struct strset *update_refs = NULL;
-	kh_oid_map_t *replayed_commits;
 	struct ref_transaction *transaction = NULL;
 	struct strbuf transaction_err = STRBUF_INIT;
 	struct strbuf reflog_msg = STRBUF_INIT;
@@ -333,13 +88,13 @@ int cmd_replay(int argc,
 		NULL
 	};
 	struct option replay_options[] = {
-		OPT_STRING(0, "advance", &advance_name_opt,
+		OPT_STRING(0, "advance", &opts.advance,
 			   N_("branch"),
 			   N_("make replay advance given branch")),
-		OPT_STRING(0, "onto", &onto_name,
+		OPT_STRING(0, "onto", &opts.onto,
 			   N_("revision"),
 			   N_("replay onto given commit")),
-		OPT_BOOL(0, "contained", &contained,
+		OPT_BOOL(0, "contained", &opts.contained,
 			 N_("update all branches that point at commits in <revision-range>")),
 		OPT_STRING(0, "ref-action", &ref_action,
 			   N_("mode"),
@@ -350,19 +105,19 @@ int cmd_replay(int argc,
 	argc = parse_options(argc, argv, prefix, replay_options, replay_usage,
 			     PARSE_OPT_KEEP_ARGV0 | PARSE_OPT_KEEP_UNKNOWN_OPT);
 
-	if (!onto_name && !advance_name_opt) {
+	if (!opts.onto && !opts.advance) {
 		error(_("option --onto or --advance is mandatory"));
 		usage_with_options(replay_usage, replay_options);
 	}
 
-	die_for_incompatible_opt2(!!advance_name_opt, "--advance",
-				  contained, "--contained");
+	die_for_incompatible_opt2(!!opts.advance, "--advance",
+				  opts.contained, "--contained");
+	die_for_incompatible_opt2(!!opts.advance, "--advance",
+				  !!opts.onto, "--onto");
 
 	/* Parse ref action mode from command line or config */
 	ref_mode = get_ref_action_mode(repo, ref_action);
 
-	advance_name = xstrdup_or_null(advance_name_opt);
-
 	repo_init_revisions(repo, &revs, prefix);
 
 	/*
@@ -414,18 +169,19 @@ int cmd_replay(int argc,
 		revs.simplify_history = 0;
 	}
 
-	set_up_replay_mode(repo, &revs.cmdline,
-			   onto_name, &advance_name,
-			   &onto, &update_refs);
-
-	/* FIXME: Should allow replaying commits with the first as a root commit */
+	ret = replay_revisions(&revs, &opts, &result);
+	if (ret)
+		goto cleanup;
 
 	/* Build reflog message */
-	if (advance_name_opt)
-		strbuf_addf(&reflog_msg, "replay --advance %s", advance_name_opt);
-	else
-		strbuf_addf(&reflog_msg, "replay --onto %s",
-			    oid_to_hex(&onto->object.oid));
+	if (opts.advance) {
+		strbuf_addf(&reflog_msg, "replay --advance %s", opts.advance);
+	} else {
+		struct object_id oid;
+		if (repo_get_oid_committish(repo, opts.onto, &oid))
+			BUG("--onto commit should have been resolved beforehand already");
+		strbuf_addf(&reflog_msg, "replay --onto %s", oid_to_hex(&oid));
+	}
 
 	/* Initialize ref transaction if using update mode */
 	if (ref_mode == REF_ACTION_UPDATE) {
@@ -438,78 +194,19 @@ int cmd_replay(int argc,
 		}
 	}
 
-	if (prepare_revision_walk(&revs) < 0) {
-		ret = error(_("error preparing revisions"));
-		goto cleanup;
-	}
-
-	init_basic_merge_options(&merge_opt, repo);
-	memset(&result, 0, sizeof(result));
-	merge_opt.show_rename_progress = 0;
-	last_commit = onto;
-	replayed_commits = kh_init_oid_map();
-	while ((commit = get_revision(&revs))) {
-		const struct name_decoration *decoration;
-		khint_t pos;
-		int hr;
-
-		if (!commit->parents)
-			die(_("replaying down from root commit is not supported yet!"));
-		if (commit->parents->next)
-			die(_("replaying merge commits is not supported yet!"));
-
-		last_commit = pick_regular_commit(repo, commit, replayed_commits,
-						  onto, &merge_opt, &result);
-		if (!last_commit)
-			break;
-
-		/* Record commit -> last_commit mapping */
-		pos = kh_put_oid_map(replayed_commits, commit->object.oid, &hr);
-		if (hr == 0)
-			BUG("Duplicate rewritten commit: %s\n",
-			    oid_to_hex(&commit->object.oid));
-		kh_value(replayed_commits, pos) = last_commit;
-
-		/* Update any necessary branches */
-		if (advance_name)
-			continue;
-		decoration = get_name_decoration(&commit->object);
-		if (!decoration)
-			continue;
-		while (decoration) {
-			if (decoration->type == DECORATION_REF_LOCAL &&
-			    (contained || strset_contains(update_refs,
-							  decoration->name))) {
-				if (handle_ref_update(ref_mode, transaction,
-						      decoration->name,
-						      &last_commit->object.oid,
-						      &commit->object.oid,
-						      reflog_msg.buf,
-						      &transaction_err) < 0) {
-					ret = error(_("failed to update ref '%s': %s"),
-						    decoration->name, transaction_err.buf);
-					goto cleanup;
-				}
-			}
-			decoration = decoration->next;
-		}
-	}
-
-	/* In --advance mode, advance the target ref */
-	if (result.clean == 1 && advance_name) {
-		if (handle_ref_update(ref_mode, transaction, advance_name,
-				      &last_commit->object.oid,
-				      &onto->object.oid,
-				      reflog_msg.buf,
-				      &transaction_err) < 0) {
+	for (size_t i = 0; i < result.updates_nr; i++) {
+		ret = handle_ref_update(ref_mode, transaction, result.updates[i].refname,
+					&result.updates[i].new_oid, &result.updates[i].old_oid,
+					reflog_msg.buf, &transaction_err);
+		if (ret) {
 			ret = error(_("failed to update ref '%s': %s"),
-				    advance_name, transaction_err.buf);
+				    result.updates[i].refname, transaction_err.buf);
 			goto cleanup;
 		}
 	}
 
 	/* Commit the ref transaction if we have one */
-	if (transaction && result.clean == 1) {
+	if (transaction) {
 		if (ref_transaction_commit(transaction, &transaction_err)) {
 			ret = error(_("failed to commit ref transaction: %s"),
 				    transaction_err.buf);
@@ -517,24 +214,18 @@ int cmd_replay(int argc,
 		}
 	}
 
-	merge_finalize(&merge_opt, &result);
-	kh_destroy_oid_map(replayed_commits);
-	if (update_refs) {
-		strset_clear(update_refs);
-		free(update_refs);
-	}
-	ret = result.clean;
+	ret = 0;
 
 cleanup:
 	if (transaction)
 		ref_transaction_free(transaction);
+	replay_result_release(&result);
 	strbuf_release(&transaction_err);
 	strbuf_release(&reflog_msg);
 	release_revisions(&revs);
-	free(advance_name);
 
 	/* Return */
 	if (ret < 0)
 		exit(128);
-	return ret ? 0 : 1;
+	return ret;
 }
diff --git a/builtin/sparse-checkout.c b/builtin/sparse-checkout.c
index 7dfb276bf01431..cccf63033190d2 100644
--- a/builtin/sparse-checkout.c
+++ b/builtin/sparse-checkout.c
@@ -293,8 +293,7 @@ static void write_cone_to_file(FILE *fp, struct pattern_list *pl)
 			string_list_append(&sl, pe->pattern);
 	}
 
-	string_list_sort(&sl);
-	string_list_remove_duplicates(&sl, 0);
+	string_list_sort_u(&sl, 0);
 
 	fprintf(fp, "/*\n!/*/\n");
 
@@ -317,8 +316,7 @@ static void write_cone_to_file(FILE *fp, struct pattern_list *pl)
 
 	strbuf_release(&parent_pattern);
 
-	string_list_sort(&sl);
-	string_list_remove_duplicates(&sl, 0);
+	string_list_sort_u(&sl, 0);
 
 	for (i = 0; i < sl.nr; i++) {
 		char *pattern = escaped_pattern(sl.items[i].string);
diff --git a/builtin/update-ref.c b/builtin/update-ref.c
index 195437e7c656ff..2d68c40ecb7010 100644
--- a/builtin/update-ref.c
+++ b/builtin/update-ref.c
@@ -573,15 +573,18 @@ static void print_rejected_refs(const char *refname,
 				const char *old_target,
 				const char *new_target,
 				enum ref_transaction_error err,
+				const char *details,
 				void *cb_data UNUSED)
 {
 	struct strbuf sb = STRBUF_INIT;
-	const char *reason = ref_transaction_error_msg(err);
+
+	if (details && *details)
+		error("%s", details);
 
 	strbuf_addf(&sb, "rejected %s %s %s %s\n", refname,
 		    new_oid ? oid_to_hex(new_oid) : new_target,
 		    old_oid ? oid_to_hex(old_oid) : old_target,
-		    reason);
+		    ref_transaction_error_msg(err));
 
 	fwrite(sb.buf, sb.len, 1, stdout);
 	strbuf_release(&sb);
diff --git a/builtin/worktree.c b/builtin/worktree.c
index fbdaf2eb2eb85c..3d6547c23b434f 100644
--- a/builtin/worktree.c
+++ b/builtin/worktree.c
@@ -252,7 +252,7 @@ static int prune(int ac, const char **av, const char *prefix,
 		OPT__DRY_RUN(&show_only, N_("do not remove, show only")),
 		OPT__VERBOSE(&verbose, N_("report pruned working trees")),
 		OPT_EXPIRY_DATE(0, "expire", &expire,
-				N_("expire working trees older than <time>")),
+				N_("prune missing working trees older than <time>")),
 		OPT_END()
 	};
 
@@ -1070,7 +1070,7 @@ static int list(int ac, const char **av, const char *prefix,
 		OPT_BOOL(0, "porcelain", &porcelain, N_("machine-readable output")),
 		OPT__VERBOSE(&verbose, N_("show extended annotations and reasons, if available")),
 		OPT_EXPIRY_DATE(0, "expire", &expire,
-				N_("add 'prunable' annotation to worktrees older than <time>")),
+				N_("add 'prunable' annotation to missing worktrees older than <time>")),
 		OPT_SET_INT('z', NULL, &line_terminator,
 			    N_("terminate records with a NUL character"), '\0'),
 		OPT_END()
diff --git a/command-list.txt b/command-list.txt
index accd3d0c4b5524..f9005cf45979f1 100644
--- a/command-list.txt
+++ b/command-list.txt
@@ -115,6 +115,7 @@ git-grep                                mainporcelain           info
 git-gui                                 mainporcelain
 git-hash-object                         plumbingmanipulators
 git-help                                ancillaryinterrogators          complete
+git-history                             mainporcelain           history
 git-hook                                purehelpers
 git-http-backend                        synchingrepositories
 git-http-fetch                          synchelpers
diff --git a/git.c b/git.c
index c5fad56813f437..744cb6527e065e 100644
--- a/git.c
+++ b/git.c
@@ -586,6 +586,7 @@ static struct cmd_struct commands[] = {
 	{ "grep", cmd_grep, RUN_SETUP_GENTLY },
 	{ "hash-object", cmd_hash_object },
 	{ "help", cmd_help },
+	{ "history", cmd_history, RUN_SETUP },
 	{ "hook", cmd_hook, RUN_SETUP },
 	{ "index-pack", cmd_index_pack, RUN_SETUP_GENTLY | NO_PARSEOPT },
 	{ "init", cmd_init_db },
diff --git a/help.c b/help.c
index 3c36d9c218f824..fefd811f7a041f 100644
--- a/help.c
+++ b/help.c
@@ -420,8 +420,7 @@ void list_cmds_by_config(struct string_list *list)
 	if (repo_config_get_string_tmp(the_repository, "completion.commands", &cmd_list))
 		return;
 
-	string_list_sort(list);
-	string_list_remove_duplicates(list, 0);
+	string_list_sort_u(list, 0);
 
 	while (*cmd_list) {
 		struct strbuf sb = STRBUF_INIT;
diff --git a/meson.build b/meson.build
index dd52efd1c87574..3a1d12caa4b94f 100644
--- a/meson.build
+++ b/meson.build
@@ -471,6 +471,7 @@ libgit_sources = [
   'repack-midx.c',
   'repack-promisor.c',
   'replace-object.c',
+  'replay.c',
   'repo-settings.c',
   'repository.c',
   'rerere.c',
@@ -609,6 +610,7 @@ builtin_sources = [
   'builtin/grep.c',
   'builtin/hash-object.c',
   'builtin/help.c',
+  'builtin/history.c',
   'builtin/hook.c',
   'builtin/index-pack.c',
   'builtin/init-db.c',
diff --git a/notes.c b/notes.c
index 8e00fd8c470dd2..090c48bbd52303 100644
--- a/notes.c
+++ b/notes.c
@@ -921,8 +921,7 @@ int combine_notes_cat_sort_uniq(struct object_id *cur_oid,
 	if (string_list_add_note_lines(&sort_uniq_list, new_oid))
 		goto out;
 	string_list_remove_empty_items(&sort_uniq_list, 0);
-	string_list_sort(&sort_uniq_list);
-	string_list_remove_duplicates(&sort_uniq_list, 0);
+	string_list_sort_u(&sort_uniq_list, 0);
 
 	/* create a new blob object from sort_uniq_list */
 	if (for_each_string_list(&sort_uniq_list,
diff --git a/refs.c b/refs.c
index 627b7f8698d044..600913b99f3f88 100644
--- a/refs.c
+++ b/refs.c
@@ -1267,6 +1267,7 @@ void ref_transaction_free(struct ref_transaction *transaction)
 		free(transaction->updates[i]->committer_info);
 		free((char *)transaction->updates[i]->new_target);
 		free((char *)transaction->updates[i]->old_target);
+		free((char *)transaction->updates[i]->rejection_details);
 		free(transaction->updates[i]);
 	}
 
@@ -1281,7 +1282,8 @@ void ref_transaction_free(struct ref_transaction *transaction)
 
 int ref_transaction_maybe_set_rejected(struct ref_transaction *transaction,
 				       size_t update_idx,
-				       enum ref_transaction_error err)
+				       enum ref_transaction_error err,
+				       struct strbuf *details)
 {
 	if (update_idx >= transaction->nr)
 		BUG("trying to set rejection on invalid update index");
@@ -1307,6 +1309,7 @@ int ref_transaction_maybe_set_rejected(struct ref_transaction *transaction,
 			   transaction->updates[update_idx]->refname, 0);
 
 	transaction->updates[update_idx]->rejection_err = err;
+	transaction->updates[update_idx]->rejection_details = strbuf_detach(details, NULL);
 	ALLOC_GROW(transaction->rejections->update_indices,
 		   transaction->rejections->nr + 1,
 		   transaction->rejections->alloc);
@@ -2698,30 +2701,33 @@ enum ref_transaction_error refs_verify_refnames_available(struct ref_store *refs
 			if (!initial_transaction &&
 			    (strset_contains(&conflicting_dirnames, dirname.buf) ||
 			     !refs_read_raw_ref(refs, dirname.buf, &oid, &referent,
-						       &type, &ignore_errno))) {
+						&type, &ignore_errno))) {
+
+				strbuf_addf(err, _("'%s' exists; cannot create '%s'"),
+					    dirname.buf, refname);
+
 				if (transaction && ref_transaction_maybe_set_rejected(
 					    transaction, *update_idx,
-					    REF_TRANSACTION_ERROR_NAME_CONFLICT)) {
+					    REF_TRANSACTION_ERROR_NAME_CONFLICT, err)) {
 					strset_remove(&dirnames, dirname.buf);
 					strset_add(&conflicting_dirnames, dirname.buf);
-					continue;
+					goto next_ref;
 				}
 
-				strbuf_addf(err, _("'%s' exists; cannot create '%s'"),
-					    dirname.buf, refname);
 				goto cleanup;
 			}
 
 			if (extras && string_list_has_string(extras, dirname.buf)) {
+				strbuf_addf(err, _("cannot process '%s' and '%s' at the same time"),
+					    refname, dirname.buf);
+
 				if (transaction && ref_transaction_maybe_set_rejected(
 					    transaction, *update_idx,
-					    REF_TRANSACTION_ERROR_NAME_CONFLICT)) {
+					    REF_TRANSACTION_ERROR_NAME_CONFLICT, err)) {
 					strset_remove(&dirnames, dirname.buf);
-					continue;
+					goto next_ref;
 				}
 
-				strbuf_addf(err, _("cannot process '%s' and '%s' at the same time"),
-					    refname, dirname.buf);
 				goto cleanup;
 			}
 		}
@@ -2751,14 +2757,14 @@ enum ref_transaction_error refs_verify_refnames_available(struct ref_store *refs
 				if (skip &&
 				    string_list_has_string(skip, iter->ref.name))
 					continue;
+				strbuf_addf(err, _("'%s' exists; cannot create '%s'"),
+					    iter->ref.name, refname);
 
 				if (transaction && ref_transaction_maybe_set_rejected(
 					    transaction, *update_idx,
-					    REF_TRANSACTION_ERROR_NAME_CONFLICT))
-					continue;
+					    REF_TRANSACTION_ERROR_NAME_CONFLICT, err))
+					goto next_ref;
 
-				strbuf_addf(err, _("'%s' exists; cannot create '%s'"),
-					    iter->ref.name, refname);
 				goto cleanup;
 			}
 
@@ -2768,15 +2774,17 @@ enum ref_transaction_error refs_verify_refnames_available(struct ref_store *refs
 
 		extra_refname = find_descendant_ref(dirname.buf, extras, skip);
 		if (extra_refname) {
+			strbuf_addf(err, _("cannot process '%s' and '%s' at the same time"),
+				    refname, extra_refname);
+
 			if (transaction && ref_transaction_maybe_set_rejected(
 				    transaction, *update_idx,
-				    REF_TRANSACTION_ERROR_NAME_CONFLICT))
-				continue;
+				    REF_TRANSACTION_ERROR_NAME_CONFLICT, err))
+				goto next_ref;
 
-			strbuf_addf(err, _("cannot process '%s' and '%s' at the same time"),
-				    refname, extra_refname);
 			goto cleanup;
 		}
+next_ref:;
 	}
 
 	ret = 0;
@@ -2905,7 +2913,7 @@ void ref_transaction_for_each_rejected_update(struct ref_transaction *transactio
 		   (update->flags & REF_HAVE_OLD) ? &update->old_oid : NULL,
 		   (update->flags & REF_HAVE_NEW) ? &update->new_oid : NULL,
 		   update->old_target, update->new_target,
-		   update->rejection_err, cb_data);
+		   update->rejection_err, update->rejection_details, cb_data);
 	}
 }
 
diff --git a/refs.h b/refs.h
index f0abfa1d93633e..f16b1b697b2bf8 100644
--- a/refs.h
+++ b/refs.h
@@ -993,6 +993,7 @@ typedef void ref_transaction_for_each_rejected_update_fn(const char *refname,
 							 const char *old_target,
 							 const char *new_target,
 							 enum ref_transaction_error err,
+							 const char *details,
 							 void *cb_data);
 void ref_transaction_for_each_rejected_update(struct ref_transaction *transaction,
 					      ref_transaction_for_each_rejected_update_fn cb,
diff --git a/refs/files-backend.c b/refs/files-backend.c
index 240d3c3b26e0b5..b1b13b41f6c7d1 100644
--- a/refs/files-backend.c
+++ b/refs/files-backend.c
@@ -2978,10 +2978,9 @@ static int files_transaction_prepare(struct ref_store *ref_store,
 					  head_ref, &refnames_to_check,
 					  err);
 		if (ret) {
-			if (ref_transaction_maybe_set_rejected(transaction, i, ret)) {
-				strbuf_reset(err);
+			if (ref_transaction_maybe_set_rejected(transaction, i,
+							       ret, err)) {
 				ret = 0;
-
 				continue;
 			}
 			goto cleanup;
diff --git a/refs/packed-backend.c b/refs/packed-backend.c
index 4ea0c1229946bd..59b3ecb9d64716 100644
--- a/refs/packed-backend.c
+++ b/refs/packed-backend.c
@@ -1437,8 +1437,8 @@ static enum ref_transaction_error write_with_updates(struct packed_ref_store *re
 						    update->refname);
 					ret = REF_TRANSACTION_ERROR_CREATE_EXISTS;
 
-					if (ref_transaction_maybe_set_rejected(transaction, i, ret)) {
-						strbuf_reset(err);
+					if (ref_transaction_maybe_set_rejected(transaction, i,
+									       ret, err)) {
 						ret = 0;
 						continue;
 					}
@@ -1452,8 +1452,8 @@ static enum ref_transaction_error write_with_updates(struct packed_ref_store *re
 						    oid_to_hex(&update->old_oid));
 					ret = REF_TRANSACTION_ERROR_INCORRECT_OLD_VALUE;
 
-					if (ref_transaction_maybe_set_rejected(transaction, i, ret)) {
-						strbuf_reset(err);
+					if (ref_transaction_maybe_set_rejected(transaction, i,
+									       ret, err)) {
 						ret = 0;
 						continue;
 					}
@@ -1496,8 +1496,8 @@ static enum ref_transaction_error write_with_updates(struct packed_ref_store *re
 					    oid_to_hex(&update->old_oid));
 				ret = REF_TRANSACTION_ERROR_NONEXISTENT_REF;
 
-				if (ref_transaction_maybe_set_rejected(transaction, i, ret)) {
-					strbuf_reset(err);
+				if (ref_transaction_maybe_set_rejected(transaction, i,
+								       ret, err)) {
 					ret = 0;
 					continue;
 				}
diff --git a/refs/refs-internal.h b/refs/refs-internal.h
index c7d2a6e50b7696..191a25683fdf31 100644
--- a/refs/refs-internal.h
+++ b/refs/refs-internal.h
@@ -128,6 +128,7 @@ struct ref_update {
 	 * was rejected.
 	 */
 	enum ref_transaction_error rejection_err;
+	const char *rejection_details;
 
 	/*
 	 * If this ref_update was split off of a symref update via
@@ -153,7 +154,8 @@ int refs_read_raw_ref(struct ref_store *ref_store, const char *refname,
  */
 int ref_transaction_maybe_set_rejected(struct ref_transaction *transaction,
 				       size_t update_idx,
-				       enum ref_transaction_error err);
+				       enum ref_transaction_error err,
+				       struct strbuf *details);
 
 /*
  * Add a ref_update with the specified properties to transaction, and
diff --git a/refs/reftable-backend.c b/refs/reftable-backend.c
index fe74af73afdb7a..5611808ad75a8b 100644
--- a/refs/reftable-backend.c
+++ b/refs/reftable-backend.c
@@ -1418,10 +1418,9 @@ static int reftable_be_transaction_prepare(struct ref_store *ref_store,
 					    &refnames_to_check, head_type,
 					    &head_referent, &referent, err);
 		if (ret) {
-			if (ref_transaction_maybe_set_rejected(transaction, i, ret)) {
-				strbuf_reset(err);
+			if (ref_transaction_maybe_set_rejected(transaction, i,
+							       ret, err)) {
 				ret = 0;
-
 				continue;
 			}
 			goto done;
diff --git a/replay.c b/replay.c
new file mode 100644
index 00000000000000..f97d652f338f1d
--- /dev/null
+++ b/replay.c
@@ -0,0 +1,375 @@
+#define USE_THE_REPOSITORY_VARIABLE
+
+#include "git-compat-util.h"
+#include "environment.h"
+#include "hex.h"
+#include "merge-ort.h"
+#include "object-name.h"
+#include "refs.h"
+#include "replay.h"
+#include "revision.h"
+#include "strmap.h"
+#include "tree.h"
+
+static const char *short_commit_name(struct repository *repo,
+				     struct commit *commit)
+{
+	return repo_find_unique_abbrev(repo, &commit->object.oid,
+				       DEFAULT_ABBREV);
+}
+
+static struct commit *peel_committish(struct repository *repo,
+				      const char *name,
+				      const char *mode)
+{
+	struct object *obj;
+	struct object_id oid;
+
+	if (repo_get_oid(repo, name, &oid))
+		die(_("'%s' is not a valid commit-ish for %s"), name, mode);
+	obj = parse_object_or_die(repo, &oid, name);
+	return (struct commit *)repo_peel_to_type(repo, name, 0, obj,
+						  OBJ_COMMIT);
+}
+
+static char *get_author(const char *message)
+{
+	size_t len;
+	const char *a;
+
+	a = find_commit_header(message, "author", &len);
+	if (a)
+		return xmemdupz(a, len);
+
+	return NULL;
+}
+
+static struct commit *create_commit(struct repository *repo,
+				    struct tree *tree,
+				    struct commit *based_on,
+				    struct commit *parent)
+{
+	struct object_id ret;
+	struct object *obj = NULL;
+	struct commit_list *parents = NULL;
+	char *author;
+	char *sign_commit = NULL; /* FIXME: cli users might want to sign again */
+	struct commit_extra_header *extra = NULL;
+	struct strbuf msg = STRBUF_INIT;
+	const char *out_enc = get_commit_output_encoding();
+	const char *message = repo_logmsg_reencode(repo, based_on,
+						   NULL, out_enc);
+	const char *orig_message = NULL;
+	const char *exclude_gpgsig[] = { "gpgsig", "gpgsig-sha256", NULL };
+
+	commit_list_insert(parent, &parents);
+	extra = read_commit_extra_headers(based_on, exclude_gpgsig);
+	find_commit_subject(message, &orig_message);
+	strbuf_addstr(&msg, orig_message);
+	author = get_author(message);
+	reset_ident_date();
+	if (commit_tree_extended(msg.buf, msg.len, &tree->object.oid, parents,
+				 &ret, author, NULL, sign_commit, extra)) {
+		error(_("failed to write commit object"));
+		goto out;
+	}
+
+	obj = parse_object(repo, &ret);
+
+out:
+	repo_unuse_commit_buffer(repo, based_on, message);
+	free_commit_extra_headers(extra);
+	free_commit_list(parents);
+	strbuf_release(&msg);
+	free(author);
+	return (struct commit *)obj;
+}
+
+struct ref_info {
+	struct commit *onto;
+	struct strset positive_refs;
+	struct strset negative_refs;
+	size_t positive_refexprs;
+	size_t negative_refexprs;
+};
+
+static void get_ref_information(struct repository *repo,
+				struct rev_cmdline_info *cmd_info,
+				struct ref_info *ref_info)
+{
+	ref_info->onto = NULL;
+	strset_init(&ref_info->positive_refs);
+	strset_init(&ref_info->negative_refs);
+	ref_info->positive_refexprs = 0;
+	ref_info->negative_refexprs = 0;
+
+	/*
+	 * When the user specifies e.g.
+	 *   git replay origin/main..mybranch
+	 *   git replay ^origin/next mybranch1 mybranch2
+	 * we want to be able to determine where to replay the commits.  In
+	 * these examples, the branches are probably based on an old version
+	 * of either origin/main or origin/next, so we want to replay on the
+	 * newest version of that branch.  In contrast we would want to error
+	 * out if they ran
+	 *   git replay ^origin/master ^origin/next mybranch
+	 *   git replay mybranch~2..mybranch
+	 * the first of those because there's no unique base to choose, and
+	 * the second because they'd likely just be replaying commits on top
+	 * of the same commit and not making any difference.
+	 */
+	for (size_t i = 0; i < cmd_info->nr; i++) {
+		struct rev_cmdline_entry *e = cmd_info->rev + i;
+		struct object_id oid;
+		const char *refexpr = e->name;
+		char *fullname = NULL;
+		int can_uniquely_dwim = 1;
+
+		if (*refexpr == '^')
+			refexpr++;
+		if (repo_dwim_ref(repo, refexpr, strlen(refexpr), &oid, &fullname, 0) != 1)
+			can_uniquely_dwim = 0;
+
+		if (e->flags & BOTTOM) {
+			if (can_uniquely_dwim)
+				strset_add(&ref_info->negative_refs, fullname);
+			if (!ref_info->negative_refexprs)
+				ref_info->onto = lookup_commit_reference_gently(repo,
+										&e->item->oid, 1);
+			ref_info->negative_refexprs++;
+		} else {
+			if (can_uniquely_dwim)
+				strset_add(&ref_info->positive_refs, fullname);
+			ref_info->positive_refexprs++;
+		}
+
+		free(fullname);
+	}
+}
+
+static void set_up_replay_mode(struct repository *repo,
+			       struct rev_cmdline_info *cmd_info,
+			       const char *onto_name,
+			       bool *detached_head,
+			       char **advance_name,
+			       struct commit **onto,
+			       struct strset **update_refs)
+{
+	struct ref_info rinfo;
+	int head_flags = 0;
+
+	refs_read_ref_full(get_main_ref_store(repo), "HEAD",
+			   RESOLVE_REF_NO_RECURSE, NULL, &head_flags);
+	*detached_head = !(head_flags & REF_ISSYMREF);
+
+	get_ref_information(repo, cmd_info, &rinfo);
+	if (!rinfo.positive_refexprs)
+		die(_("need some commits to replay"));
+
+	if (!onto_name == !*advance_name)
+		BUG("one and only one of onto_name and *advance_name must be given");
+
+	if (onto_name) {
+		*onto = peel_committish(repo, onto_name, "--onto");
+		if (rinfo.positive_refexprs <
+		    strset_get_size(&rinfo.positive_refs))
+			die(_("all positive revisions given must be references"));
+		*update_refs = xcalloc(1, sizeof(**update_refs));
+		**update_refs = rinfo.positive_refs;
+		memset(&rinfo.positive_refs, 0, sizeof(**update_refs));
+	} else {
+		struct object_id oid;
+		char *fullname = NULL;
+
+		if (!*advance_name)
+			BUG("expected either onto_name or *advance_name in this function");
+
+		if (repo_dwim_ref(repo, *advance_name, strlen(*advance_name),
+			     &oid, &fullname, 0) == 1) {
+			free(*advance_name);
+			*advance_name = fullname;
+		} else {
+			die(_("argument to --advance must be a reference"));
+		}
+		*onto = peel_committish(repo, *advance_name, "--advance");
+		if (rinfo.positive_refexprs > 1)
+			die(_("cannot advance target with multiple sources because ordering would be ill-defined"));
+	}
+	strset_clear(&rinfo.negative_refs);
+	strset_clear(&rinfo.positive_refs);
+}
+
+static struct commit *mapped_commit(kh_oid_map_t *replayed_commits,
+				    struct commit *commit,
+				    struct commit *fallback)
+{
+	khint_t pos = kh_get_oid_map(replayed_commits, commit->object.oid);
+	if (pos == kh_end(replayed_commits))
+		return fallback;
+	return kh_value(replayed_commits, pos);
+}
+
+static struct commit *pick_regular_commit(struct repository *repo,
+					  struct commit *pickme,
+					  kh_oid_map_t *replayed_commits,
+					  struct commit *onto,
+					  struct merge_options *merge_opt,
+					  struct merge_result *result)
+{
+	struct commit *base, *replayed_base;
+	struct tree *pickme_tree, *base_tree, *replayed_base_tree;
+
+	base = pickme->parents->item;
+	replayed_base = mapped_commit(replayed_commits, base, onto);
+
+	replayed_base_tree = repo_get_commit_tree(repo, replayed_base);
+	pickme_tree = repo_get_commit_tree(repo, pickme);
+	base_tree = repo_get_commit_tree(repo, base);
+
+	merge_opt->branch1 = short_commit_name(repo, replayed_base);
+	merge_opt->branch2 = short_commit_name(repo, pickme);
+	merge_opt->ancestor = xstrfmt("parent of %s", merge_opt->branch2);
+
+	merge_incore_nonrecursive(merge_opt,
+				  base_tree,
+				  replayed_base_tree,
+				  pickme_tree,
+				  result);
+
+	free((char*)merge_opt->ancestor);
+	merge_opt->ancestor = NULL;
+	if (!result->clean)
+		return NULL;
+	/* Drop commits that become empty */
+	if (oideq(&replayed_base_tree->object.oid, &result->tree->object.oid) &&
+	    !oideq(&pickme_tree->object.oid, &base_tree->object.oid))
+		return replayed_base;
+	return create_commit(repo, result->tree, pickme, replayed_base);
+}
+
+void replay_result_release(struct replay_result *result)
+{
+	for (size_t i = 0; i < result->updates_nr; i++)
+		free(result->updates[i].refname);
+	free(result->updates);
+}
+
+static void replay_result_queue_update(struct replay_result *result,
+				       const char *refname,
+				       const struct object_id *old_oid,
+				       const struct object_id *new_oid)
+{
+	ALLOC_GROW(result->updates, result->updates_nr + 1, result->updates_alloc);
+	result->updates[result->updates_nr].refname = xstrdup(refname);
+	result->updates[result->updates_nr].old_oid = *old_oid;
+	result->updates[result->updates_nr].new_oid = *new_oid;
+	result->updates_nr++;
+}
+
+int replay_revisions(struct rev_info *revs,
+		     struct replay_revisions_options *opts,
+		     struct replay_result *out)
+{
+	kh_oid_map_t *replayed_commits = NULL;
+	struct strset *update_refs = NULL;
+	struct commit *last_commit = NULL;
+	struct commit *commit;
+	struct commit *onto = NULL;
+	struct merge_options merge_opt;
+	struct merge_result result = {
+		.clean = 1,
+	};
+	bool detached_head;
+	char *advance;
+	int ret;
+
+	advance = xstrdup_or_null(opts->advance);
+	set_up_replay_mode(revs->repo, &revs->cmdline, opts->onto,
+			   &detached_head, &advance, &onto, &update_refs);
+
+	/* FIXME: Should allow replaying commits with the first as a root commit */
+
+	if (prepare_revision_walk(revs) < 0) {
+		ret = error(_("error preparing revisions"));
+		goto out;
+	}
+
+	init_basic_merge_options(&merge_opt, revs->repo);
+	merge_opt.show_rename_progress = 0;
+	last_commit = onto;
+	replayed_commits = kh_init_oid_map();
+	while ((commit = get_revision(revs))) {
+		const struct name_decoration *decoration;
+		khint_t pos;
+		int hr;
+
+		if (!commit->parents)
+			die(_("replaying down from root commit is not supported yet!"));
+		if (commit->parents->next)
+			die(_("replaying merge commits is not supported yet!"));
+
+		last_commit = pick_regular_commit(revs->repo, commit, replayed_commits,
+						  onto, &merge_opt, &result);
+		if (!last_commit)
+			break;
+
+		/* Record commit -> last_commit mapping */
+		pos = kh_put_oid_map(replayed_commits, commit->object.oid, &hr);
+		if (hr == 0)
+			BUG("Duplicate rewritten commit: %s\n",
+			    oid_to_hex(&commit->object.oid));
+		kh_value(replayed_commits, pos) = last_commit;
+
+		/* Update any necessary branches */
+		if (advance)
+			continue;
+
+		for (decoration = get_name_decoration(&commit->object);
+		     decoration;
+		     decoration = decoration->next)
+		{
+			if (decoration->type != DECORATION_REF_LOCAL &&
+			    decoration->type != DECORATION_REF_HEAD)
+				continue;
+
+			/*
+			 * We only need to update HEAD separately in case it's
+			 * detached. If it's not we'd already update the branch
+			 * it is pointing to.
+			 */
+			if (decoration->type == DECORATION_REF_HEAD && !detached_head)
+				continue;
+
+			if (!opts->contained &&
+			    !strset_contains(update_refs, decoration->name))
+				continue;
+
+			replay_result_queue_update(out, decoration->name,
+						   &commit->object.oid,
+						   &last_commit->object.oid);
+		}
+	}
+
+	if (!result.clean) {
+		ret = 1;
+		goto out;
+	}
+
+	/* In --advance mode, advance the target ref */
+	if (advance)
+		replay_result_queue_update(out, advance,
+					   &onto->object.oid,
+					   &last_commit->object.oid);
+
+	ret = 0;
+
+out:
+	if (update_refs) {
+		strset_clear(update_refs);
+		free(update_refs);
+	}
+	kh_destroy_oid_map(replayed_commits);
+	merge_finalize(&merge_opt, &result);
+	free(advance);
+	return ret;
+}
diff --git a/replay.h b/replay.h
new file mode 100644
index 00000000000000..d8407dc7f710fc
--- /dev/null
+++ b/replay.h
@@ -0,0 +1,61 @@
+#ifndef REPLAY_H
+#define REPLAY_H
+
+#include "hash.h"
+
+struct repository;
+struct rev_info;
+
+/*
+ * A set of options that can be passed to `replay_revisions()`.
+ */
+struct replay_revisions_options {
+	/*
+	 * Starting point at which to create the new commits; must be a branch
+	 * name. The branch will be updated to point to the rewritten commits.
+	 * This option is mutually exclusive with `onto`.
+	 */
+	const char *advance;
+
+	/*
+	 * Starting point at which to create the new commits; must be a
+	 * committish. References pointing at decendants of `onto` will be
+	 * updated to point to the new commits.
+	 */
+	 const char *onto;
+
+	/*
+	 * Update branches that point at commits in the given revision range.
+	 * Requires `onto` to be set.
+	 */
+	int contained;
+};
+
+/* This struct is used as an out-parameter by `replay_revisions()`. */
+struct replay_result {
+	/*
+	 * The set of reference updates that are caused by replaying the
+	 * commits.
+	 */
+	struct replay_ref_update {
+		char *refname;
+		struct object_id old_oid;
+		struct object_id new_oid;
+	} *updates;
+	size_t updates_nr, updates_alloc;
+};
+
+void replay_result_release(struct replay_result *result);
+
+/*
+ * Replay a set of commits onto a new location. Leaves both the working tree,
+ * index and references untouched. Reference updates caused by the replay will
+ * be recorded in the `updates` out pointer.
+ *
+ * Returns 0 on success, 1 on conflict and a negative error code otherwise.
+ */
+int replay_revisions(struct rev_info *revs,
+		     struct replay_revisions_options *opts,
+		     struct replay_result *out);
+
+#endif
diff --git a/string-list.c b/string-list.c
index 08dc00984ccbd6..020ed8fef7057d 100644
--- a/string-list.c
+++ b/string-list.c
@@ -247,6 +247,12 @@ void string_list_sort(struct string_list *list)
 	QSORT_S(list->items, list->nr, cmp_items, &sort_ctx);
 }
 
+void string_list_sort_u(struct string_list *list, int free_util)
+{
+	string_list_sort(list);
+	string_list_remove_duplicates(list, free_util);
+}
+
 struct string_list_item *unsorted_string_list_lookup(struct string_list *list,
 						     const char *string)
 {
diff --git a/string-list.h b/string-list.h
index fa6ba07853c52b..3ad862a18718a4 100644
--- a/string-list.h
+++ b/string-list.h
@@ -239,6 +239,12 @@ struct string_list_item *string_list_append_nodup(struct string_list *list, char
  */
 void string_list_sort(struct string_list *list);
 
+/**
+ * Sort the list and then remove duplicate entries.  If free_util is true,
+ * call free() on the util members of any items that have to be deleted.
+ */
+void string_list_sort_u(struct string_list *list, int free_util);
+
 /**
  * Like `string_list_has_string()` but for unsorted lists. Linear in
  * size of the list.
diff --git a/t/meson.build b/t/meson.build
index 19e8306298eff5..a04a7a86cfe4af 100644
--- a/t/meson.build
+++ b/t/meson.build
@@ -387,6 +387,8 @@ integration_tests = [
   't3436-rebase-more-options.sh',
   't3437-rebase-fixup-options.sh',
   't3438-rebase-broken-files.sh',
+  't3450-history.sh',
+  't3451-history-reword.sh',
   't3500-cherry.sh',
   't3501-revert-cherry-pick.sh',
   't3502-cherry-pick-merge.sh',
diff --git a/t/perf/p3400-rebase.sh b/t/perf/p3400-rebase.sh
index e6b0277729b196..56dc3e1d319c7d 100755
--- a/t/perf/p3400-rebase.sh
+++ b/t/perf/p3400-rebase.sh
@@ -9,21 +9,44 @@ test_expect_success 'setup rebasing on top of a lot of changes' '
 	git checkout -f -B base &&
 	git checkout -B to-rebase &&
 	git checkout -B upstream &&
-	for i in $(test_seq 100)
-	do
-		# simulate huge diffs
-		echo change$i >unrelated-file$i &&
-		test_seq 1000 >>unrelated-file$i &&
-		git add unrelated-file$i &&
-		test_tick &&
-		git commit -m commit$i unrelated-file$i &&
-		echo change$i >unrelated-file$i &&
-		test_seq 1000 | sort -nr >>unrelated-file$i &&
-		git add unrelated-file$i &&
-		test_tick &&
-		git commit -m commit$i-reverse unrelated-file$i ||
-		return 1
-	done &&
+	test_seq 1000 >content_fwd &&
+	sort -nr content_fwd >content_rev &&
+	(
+		for i in $(test_seq 100)
+		do
+			test_tick &&
+			echo "commit refs/heads/upstream" &&
+			echo "committer $GIT_COMMITTER_NAME <$GIT_COMMITTER_EMAIL> $GIT_COMMITTER_DATE" &&
+			echo "data <<EOF" &&
+			echo "commit$i" &&
+			echo "EOF" &&
+
+			if test "$i" = 1; then
+				echo "from refs/heads/upstream^0"
+			fi &&
+
+			echo "M 100644 inline unrelated-file$i" &&
+			echo "data <<EOF" &&
+			echo "change$i" &&
+			cat content_fwd &&
+			echo "EOF" &&
+
+			echo "commit refs/heads/upstream" &&
+			echo "committer $GIT_COMMITTER_NAME <$GIT_COMMITTER_EMAIL> $GIT_COMMITTER_DATE" &&
+			echo "data <<EOF" &&
+			echo "commit$i-reverse" &&
+			echo "EOF" &&
+			echo "M 100644 inline unrelated-file$i" &&
+			echo "data <<EOF" &&
+			echo "change$i" &&
+			cat content_rev &&
+			echo "EOF" || exit 1
+		done
+	) >fast_import_stream &&
+
+	git fast-import <fast_import_stream &&
+	git repack -a -d &&
+	git checkout -f upstream &&
 	git checkout to-rebase &&
 	test_commit our-patch interesting-file
 '
diff --git a/t/t1400-update-ref.sh b/t/t1400-update-ref.sh
index db7f5444da2162..db6585b8d828a5 100755
--- a/t/t1400-update-ref.sh
+++ b/t/t1400-update-ref.sh
@@ -2093,14 +2093,15 @@ do
 
 			format_command $type "update refs/heads/ref1" "$old_head" "$head" >stdin &&
 			format_command $type "update refs/heads/ref2" "$(test_oid 001)" "$head" >>stdin &&
-			git update-ref $type --stdin --batch-updates <stdin >stdout &&
+			git update-ref $type --stdin --batch-updates <stdin >stdout 2>err &&
 			echo $old_head >expect &&
 			git rev-parse refs/heads/ref1 >actual &&
 			test_cmp expect actual &&
 			echo $head >expect &&
 			git rev-parse refs/heads/ref2 >actual &&
 			test_cmp expect actual &&
-			test_grep -q "invalid new value provided" stdout
+			test_grep "rejected refs/heads/ref2 $(test_oid 001) $head invalid new value provided" stdout &&
+			test_grep "trying to write ref ${SQ}refs/heads/ref2${SQ} with nonexistent object" err
 		)
 	'
 
@@ -2119,14 +2120,15 @@ do
 
 			format_command $type "update refs/heads/ref1" "$old_head" "$head" >stdin &&
 			format_command $type "update refs/heads/ref2" "$head_tree" "$head" >>stdin &&
-			git update-ref $type --stdin --batch-updates <stdin >stdout &&
+			git update-ref $type --stdin --batch-updates <stdin >stdout 2>err &&
 			echo $old_head >expect &&
 			git rev-parse refs/heads/ref1 >actual &&
 			test_cmp expect actual &&
 			echo $head >expect &&
 			git rev-parse refs/heads/ref2 >actual &&
 			test_cmp expect actual &&
-			test_grep -q "invalid new value provided" stdout
+			test_grep "rejected refs/heads/ref2 $head_tree $head invalid new value provided" stdout &&
+			test_grep "trying to write non-commit object $head_tree to branch ${SQ}refs/heads/ref2${SQ}" err
 		)
 	'
 
@@ -2143,12 +2145,13 @@ do
 
 			format_command $type "update refs/heads/ref1" "$old_head" "$head" >stdin &&
 			format_command $type "update refs/heads/ref2" "$old_head" "$head" >>stdin &&
-			git update-ref $type --stdin --batch-updates <stdin >stdout &&
+			git update-ref $type --stdin --batch-updates <stdin >stdout 2>err &&
 			echo $old_head >expect &&
 			git rev-parse refs/heads/ref1 >actual &&
 			test_cmp expect actual &&
 			test_must_fail git rev-parse refs/heads/ref2 &&
-			test_grep -q "reference does not exist" stdout
+			test_grep "rejected refs/heads/ref2 $old_head $head reference does not exist" stdout &&
+			test_grep "cannot lock ref ${SQ}refs/heads/ref2${SQ}: unable to resolve reference ${SQ}refs/heads/ref2${SQ}" err
 		)
 	'
 
@@ -2166,13 +2169,14 @@ do
 
 			format_command $type "update refs/heads/ref1" "$old_head" "$head" >stdin &&
 			format_command $type "update refs/heads/ref2" "$old_head" "$head" >>stdin &&
-			git update-ref $type --no-deref --stdin --batch-updates <stdin >stdout &&
+			git update-ref $type --no-deref --stdin --batch-updates <stdin >stdout 2>err &&
 			echo $old_head >expect &&
 			git rev-parse refs/heads/ref1 >actual &&
 			test_cmp expect actual &&
 			echo $head >expect &&
 			test_must_fail git rev-parse refs/heads/ref2 &&
-			test_grep -q "reference does not exist" stdout
+			test_grep "rejected refs/heads/ref2 $old_head $head reference does not exist" stdout &&
+			test_grep "cannot lock ref ${SQ}refs/heads/ref2${SQ}: reference is missing but expected $head" err
 		)
 	'
 
@@ -2190,7 +2194,7 @@ do
 
 			format_command $type "update refs/heads/ref1" "$old_head" "$head" >stdin &&
 			format_command $type "symref-update refs/heads/ref2" "$old_head" "ref" "refs/heads/nonexistent" >>stdin &&
-			git update-ref $type --no-deref --stdin --batch-updates <stdin >stdout &&
+			git update-ref $type --no-deref --stdin --batch-updates <stdin >stdout 2>err &&
 			echo $old_head >expect &&
 			git rev-parse refs/heads/ref1 >actual &&
 			test_cmp expect actual &&
@@ -2198,7 +2202,8 @@ do
 			echo $head >expect &&
 			git rev-parse refs/heads/ref2 >actual &&
 			test_cmp expect actual &&
-			test_grep -q "expected symref but found regular ref" stdout
+			test_grep "rejected refs/heads/ref2 $ZERO_OID $ZERO_OID expected symref but found regular ref" stdout &&
+			test_grep "cannot lock ref ${SQ}refs/heads/ref2${SQ}: expected symref with target ${SQ}refs/heads/nonexistent${SQ}: but is a regular ref" err
 		)
 	'
 
@@ -2216,14 +2221,15 @@ do
 
 			format_command $type "update refs/heads/ref1" "$old_head" "$head" >stdin &&
 			format_command $type "update refs/heads/ref2" "$old_head" "$Z" >>stdin &&
-			git update-ref $type --stdin --batch-updates <stdin >stdout &&
+			git update-ref $type --stdin --batch-updates <stdin >stdout 2>err &&
 			echo $old_head >expect &&
 			git rev-parse refs/heads/ref1 >actual &&
 			test_cmp expect actual &&
 			echo $head >expect &&
 			git rev-parse refs/heads/ref2 >actual &&
 			test_cmp expect actual &&
-			test_grep -q "reference already exists" stdout
+			test_grep "rejected refs/heads/ref2 $old_head $ZERO_OID reference already exists" stdout &&
+			test_grep "cannot lock ref ${SQ}refs/heads/ref2${SQ}: reference already exists" err
 		)
 	'
 
@@ -2241,14 +2247,15 @@ do
 
 			format_command $type "update refs/heads/ref1" "$old_head" "$head" >stdin &&
 			format_command $type "update refs/heads/ref2" "$head" "$old_head" >>stdin &&
-			git update-ref $type --stdin --batch-updates <stdin >stdout &&
+			git update-ref $type --stdin --batch-updates <stdin >stdout 2>err &&
 			echo $old_head >expect &&
 			git rev-parse refs/heads/ref1 >actual &&
 			test_cmp expect actual &&
 			echo $head >expect &&
 			git rev-parse refs/heads/ref2 >actual &&
 			test_cmp expect actual &&
-			test_grep -q "incorrect old value provided" stdout
+			test_grep "rejected refs/heads/ref2 $head $old_head incorrect old value provided" stdout &&
+			test_grep "cannot lock ref ${SQ}refs/heads/ref2${SQ}: is at $head but expected $old_head" err
 		)
 	'
 
@@ -2264,12 +2271,13 @@ do
 			git update-ref refs/heads/ref/foo $head &&
 
 			format_command $type "update refs/heads/ref/foo" "$old_head" "$head" >stdin &&
-			format_command $type "update refs/heads/ref" "$old_head" "" >>stdin &&
-			git update-ref $type --stdin --batch-updates <stdin >stdout &&
+			format_command $type "update refs/heads/ref" "$old_head" "$ZERO_OID" >>stdin &&
+			git update-ref $type --stdin --batch-updates <stdin >stdout 2>err &&
 			echo $old_head >expect &&
 			git rev-parse refs/heads/ref/foo >actual &&
 			test_cmp expect actual &&
-			test_grep -q "refname conflict" stdout
+			test_grep "rejected refs/heads/ref $old_head $ZERO_OID refname conflict" stdout &&
+			test_grep "${SQ}refs/heads/ref/foo${SQ} exists; cannot create ${SQ}refs/heads/ref${SQ}" err
 		)
 	'
 
@@ -2284,13 +2292,14 @@ do
 			head=$(git rev-parse HEAD) &&
 			git update-ref refs/heads/ref/foo $head &&
 
-			format_command $type "update refs/heads/foo" "$old_head" "" >stdin &&
-			format_command $type "update refs/heads/ref" "$old_head" "" >>stdin &&
-			git update-ref $type --stdin --batch-updates <stdin >stdout &&
+			format_command $type "update refs/heads/foo" "$old_head" "$ZERO_OID" >stdin &&
+			format_command $type "update refs/heads/ref" "$old_head" "$ZERO_OID" >>stdin &&
+			git update-ref $type --stdin --batch-updates <stdin >stdout 2>err &&
 			echo $old_head >expect &&
 			git rev-parse refs/heads/foo >actual &&
 			test_cmp expect actual &&
-			test_grep -q "refname conflict" stdout
+			test_grep "rejected refs/heads/ref $old_head $ZERO_OID refname conflict" stdout &&
+			test_grep "${SQ}refs/heads/ref/foo${SQ} exists; cannot create ${SQ}refs/heads/ref${SQ}" err
 		)
 	'
 
@@ -2309,14 +2318,15 @@ do
 				format_command $type "create refs/heads/ref" "$old_head" &&
 				format_command $type "create refs/heads/Foo" "$old_head"
 			} >stdin &&
-			git update-ref $type --stdin --batch-updates <stdin >stdout &&
+			git update-ref $type --stdin --batch-updates <stdin >stdout 2>err &&
 
 			echo $head >expect &&
 			git rev-parse refs/heads/foo >actual &&
 			echo $old_head >expect &&
 			git rev-parse refs/heads/ref >actual &&
 			test_cmp expect actual &&
-			test_grep -q "reference conflict due to case-insensitive filesystem" stdout
+			test_grep "rejected refs/heads/Foo $old_head $ZERO_OID reference conflict due to case-insensitive filesystem" stdout &&
+			test_grep -e "cannot lock ref ${SQ}refs/heads/Foo${SQ}: Unable to create" -e "Foo.lock" err
 		)
 	'
 
@@ -2357,8 +2367,9 @@ do
 			git symbolic-ref refs/heads/symbolic refs/heads/non-existent &&
 
 			format_command $type "delete refs/heads/symbolic" "$head" >stdin &&
-			git update-ref $type --stdin --batch-updates <stdin >stdout &&
-			test_grep "reference does not exist" stdout
+			git update-ref $type --stdin --batch-updates <stdin >stdout 2>err &&
+			test_grep "rejected refs/heads/non-existent $ZERO_OID $head reference does not exist" stdout &&
+			test_grep "cannot lock ref ${SQ}refs/heads/symbolic${SQ}: unable to resolve reference ${SQ}refs/heads/non-existent${SQ}" err
 		)
 	'
 
@@ -2373,8 +2384,9 @@ do
 			head=$(git rev-parse HEAD) &&
 
 			format_command $type "delete refs/heads/new-branch" "$head" >stdin &&
-			git update-ref $type --stdin --batch-updates <stdin >stdout &&
-			test_grep "incorrect old value provided" stdout
+			git update-ref $type --stdin --batch-updates <stdin >stdout 2>err &&
+			test_grep "rejected refs/heads/new-branch $ZERO_OID $head incorrect old value provided" stdout &&
+			test_grep "cannot lock ref ${SQ}refs/heads/new-branch${SQ}: is at $(git rev-parse new-branch) but expected $head" err
 		)
 	'
 
@@ -2387,8 +2399,9 @@ do
 			head=$(git rev-parse HEAD) &&
 
 			format_command $type "delete refs/heads/non-existent" "$head" >stdin &&
-			git update-ref $type --stdin --batch-updates <stdin >stdout &&
-			test_grep "reference does not exist" stdout
+			git update-ref $type --stdin --batch-updates <stdin >stdout 2>err &&
+			test_grep "rejected refs/heads/non-existent $ZERO_OID $head reference does not exist" stdout &&
+			test_grep "cannot lock ref ${SQ}refs/heads/non-existent${SQ}: unable to resolve reference ${SQ}refs/heads/non-existent${SQ}" err
 		)
 	'
 done
diff --git a/t/t3450-history.sh b/t/t3450-history.sh
new file mode 100755
index 00000000000000..f513463b92bf43
--- /dev/null
+++ b/t/t3450-history.sh
@@ -0,0 +1,17 @@
+#!/bin/sh
+
+test_description='tests for git-history command'
+
+. ./test-lib.sh
+
+test_expect_success 'does nothing without any arguments' '
+	test_must_fail git history 2>err &&
+	test_grep "need a subcommand" err
+'
+
+test_expect_success 'raises an error with unknown argument' '
+	test_must_fail git history garbage 2>err &&
+	test_grep "unknown subcommand: .garbage." err
+'
+
+test_done
diff --git a/t/t3451-history-reword.sh b/t/t3451-history-reword.sh
new file mode 100755
index 00000000000000..3594421b681c40
--- /dev/null
+++ b/t/t3451-history-reword.sh
@@ -0,0 +1,391 @@
+#!/bin/sh
+
+test_description='tests for git-history reword subcommand'
+
+. ./test-lib.sh
+. "$TEST_DIRECTORY/lib-log-graph.sh"
+
+reword_with_message () {
+	cat >message &&
+	write_script fake-editor.sh <<-\EOF &&
+	cp message "$1"
+	EOF
+	test_set_editor "$(pwd)"/fake-editor.sh &&
+	git history reword "$@" &&
+	rm fake-editor.sh message
+}
+
+expect_graph () {
+	cat >expect &&
+	lib_test_cmp_graph --graph --format=%s "$@"
+}
+
+expect_log () {
+	git log --format="%s" "$@" >actual &&
+	cat >expect &&
+	test_cmp expect actual
+}
+
+test_expect_success 'can reword tip of a branch' '
+	test_when_finished "rm -rf repo" &&
+	git init repo &&
+	(
+		cd repo &&
+		test_commit first &&
+		test_commit second &&
+		test_commit third &&
+
+		git symbolic-ref HEAD >expect &&
+		reword_with_message HEAD <<-EOF &&
+		third reworded
+		EOF
+		git symbolic-ref HEAD >actual &&
+		test_cmp expect actual &&
+
+		expect_log <<-\EOF &&
+		third reworded
+		second
+		first
+		EOF
+
+		git reflog >reflog &&
+		test_grep "reword: updating HEAD" reflog
+	)
+'
+
+test_expect_success 'can reword commit in the middle' '
+	test_when_finished "rm -rf repo" &&
+	git init repo &&
+	(
+		cd repo &&
+		test_commit first &&
+		test_commit second &&
+		test_commit third &&
+
+		git symbolic-ref HEAD >expect &&
+		reword_with_message HEAD~ <<-EOF &&
+		second reworded
+		EOF
+		git symbolic-ref HEAD >actual &&
+		test_cmp expect actual &&
+
+		expect_log <<-\EOF
+		third
+		second reworded
+		first
+		EOF
+	)
+'
+
+test_expect_success 'can reword commit in the middle even on detached head' '
+	test_when_finished "rm -rf repo" &&
+	git init repo &&
+	(
+		cd repo &&
+		test_commit first &&
+		test_commit second &&
+		test_commit third_on_main &&
+		git checkout --detach HEAD^ &&
+		test_commit third_on_head &&
+
+		reword_with_message HEAD~ <<-EOF &&
+		second reworded
+		EOF
+
+		expect_graph HEAD --branches <<-\EOF
+		* third_on_head
+		| * third_on_main
+		|/
+		* second reworded
+		* first
+		EOF
+       )
+'
+
+test_expect_success 'can reword the detached head' '
+	test_when_finished "rm -rf repo" &&
+	git init repo &&
+	(
+		cd repo &&
+		test_commit first &&
+		test_commit second &&
+		git checkout --detach HEAD &&
+		test_commit third &&
+
+		reword_with_message HEAD <<-EOF &&
+		third reworded
+		EOF
+
+		expect_log <<-\EOF
+		third reworded
+		second
+		first
+		EOF
+	)
+'
+
+test_expect_success 'can reword root commit' '
+	test_when_finished "rm -rf repo" &&
+	git init repo &&
+	(
+		cd repo &&
+		test_commit first &&
+		test_commit second &&
+		test_commit third &&
+		reword_with_message HEAD~2 <<-EOF &&
+		first reworded
+		EOF
+
+		expect_log <<-\EOF
+		third
+		second
+		first reworded
+		EOF
+	)
+'
+
+test_expect_success 'can reword in a bare repo' '
+	test_when_finished "rm -rf repo repo.git" &&
+	git init repo &&
+	test_commit -C repo first &&
+	git clone --bare repo repo.git &&
+	(
+		cd repo.git &&
+		reword_with_message HEAD <<-EOF &&
+		reworded
+		EOF
+
+		expect_log <<-\EOF
+		reworded
+		EOF
+	)
+'
+
+test_expect_success 'can reword a commit on a different branch' '
+	test_when_finished "rm -rf repo" &&
+	git init repo &&
+	(
+		cd repo &&
+		test_commit base &&
+		git branch theirs &&
+		test_commit ours &&
+		git switch theirs &&
+		test_commit theirs &&
+
+		git rev-parse ours >ours-before &&
+		reword_with_message theirs <<-EOF &&
+		Reworded theirs
+		EOF
+		git rev-parse ours >ours-after &&
+		test_cmp ours-before ours-after &&
+
+		expect_graph --branches <<-\EOF
+		* Reworded theirs
+		| * ours
+		|/
+		* base
+		EOF
+	)
+'
+
+test_expect_success 'can reword a merge commit' '
+	test_when_finished "rm -rf repo" &&
+	git init repo &&
+	(
+		cd repo &&
+		test_commit base &&
+		git branch branch &&
+		test_commit ours &&
+		git switch branch &&
+		test_commit theirs &&
+		git switch - &&
+		git merge theirs &&
+
+		# It is not possible to replay merge commits embedded in the
+		# history (yet).
+		test_must_fail git history reword HEAD~ 2>err &&
+		test_grep "replaying merge commits is not supported yet" err &&
+
+		# But it is possible to reword a merge commit directly.
+		reword_with_message HEAD <<-EOF &&
+		Reworded merge commit
+		EOF
+		expect_graph <<-\EOF
+		*   Reworded merge commit
+		|\
+		| * theirs
+		* | ours
+		|/
+		* base
+		EOF
+	)
+'
+
+test_expect_success '--ref-action=print prints ref updates without modifying repo' '
+	test_when_finished "rm -rf repo" &&
+	git init repo --initial-branch=main &&
+	(
+		cd repo &&
+		test_commit base &&
+		git branch branch &&
+		test_commit ours &&
+		git switch branch &&
+		test_commit theirs &&
+
+		git refs list >refs-expect &&
+		reword_with_message --ref-action=print base >updates <<-\EOF &&
+		reworded commit
+		EOF
+		git refs list >refs-actual &&
+		test_cmp refs-expect refs-actual &&
+
+		test_grep "update refs/heads/branch" updates &&
+		test_grep "update refs/heads/main" updates &&
+		git update-ref --stdin <updates &&
+		expect_log --branches <<-\EOF
+		theirs
+		ours
+		reworded commit
+		EOF
+	)
+'
+
+test_expect_success '--ref-action=head updates only HEAD' '
+	test_when_finished "rm -rf repo" &&
+	git init repo --initial-branch=main &&
+	(
+		cd repo &&
+		test_commit base &&
+		git branch branch &&
+		test_commit theirs &&
+		git switch branch &&
+		test_commit ours &&
+
+		# When told to update HEAD, only, the command will refuse to
+		# rewrite commits that are not an ancestor of HEAD.
+		test_must_fail git history reword --ref-action=head theirs 2>err &&
+		test_grep "rewritten commit must be an ancestor of HEAD" err &&
+
+		reword_with_message --ref-action=head base >updates <<-\EOF &&
+		reworded base
+		EOF
+		expect_log HEAD <<-\EOF &&
+		ours
+		reworded base
+		EOF
+		expect_log main <<-\EOF
+		theirs
+		base
+		EOF
+	)
+'
+
+test_expect_success 'editor shows proper status' '
+	test_when_finished "rm -rf repo" &&
+	git init repo &&
+	(
+		cd repo &&
+		test_commit first &&
+
+		write_script fake-editor.sh <<-\EOF &&
+		cp "$1" . &&
+		printf "\namend a comment\n" >>"$1"
+		EOF
+		test_set_editor "$(pwd)"/fake-editor.sh &&
+		git history reword HEAD &&
+
+		cat >expect <<-EOF &&
+		first
+
+		# Please enter the commit message for the reworded changes. Lines starting
+		# with ${SQ}#${SQ} will be ignored, and an empty message aborts the commit.
+		# Changes to be committed:
+		#	new file:   first.t
+		#
+		EOF
+		test_cmp expect COMMIT_EDITMSG &&
+
+		test_commit_message HEAD <<-\EOF
+		first
+
+		amend a comment
+		EOF
+	)
+'
+
+# For now, git-history(1) does not yet execute any hooks. This is subject to
+# change in the future, and if it does this test here is expected to start
+# failing. In other words, this test is not an endorsement of the current
+# status quo.
+test_expect_success 'hooks are not executed for rewritten commits' '
+	test_when_finished "rm -rf repo" &&
+	git init repo &&
+	(
+		cd repo &&
+		test_commit first &&
+		test_commit second &&
+		test_commit third &&
+
+		ORIG_PATH="$(pwd)" &&
+		export ORIG_PATH &&
+		for hook in prepare-commit-msg pre-commit post-commit post-rewrite commit-msg
+		do
+			write_script .git/hooks/$hook <<-\EOF || exit 1
+			touch "$ORIG_PATH/hooks.log
+			EOF
+		done &&
+
+		reword_with_message HEAD~ <<-EOF &&
+		second reworded
+		EOF
+
+		cat >expect <<-EOF &&
+		third
+		second reworded
+		first
+		EOF
+		git log --format=%s >actual &&
+		test_cmp expect actual &&
+
+		test_path_is_missing hooks.log
+	)
+'
+
+test_expect_success 'aborts with empty commit message' '
+	test_when_finished "rm -rf repo" &&
+	git init repo &&
+	(
+		cd repo &&
+		test_commit first &&
+
+		! reword_with_message HEAD 2>err </dev/null &&
+		test_grep "Aborting commit due to empty commit message." err
+	)
+'
+
+test_expect_success 'retains changes in the worktree and index' '
+	test_when_finished "rm -rf repo" &&
+	git init repo &&
+	(
+		cd repo &&
+		touch a b &&
+		git add . &&
+		git commit -m "initial commit" &&
+		echo foo >a &&
+		echo bar >b &&
+		git add b &&
+		reword_with_message HEAD <<-EOF &&
+		message
+		EOF
+		cat >expect <<-\EOF &&
+		 M a
+		M  b
+		?? actual
+		?? expect
+		EOF
+		git status --porcelain >actual &&
+		test_cmp expect actual
+	)
+'
+
+test_done
diff --git a/t/t3650-replay-basics.sh b/t/t3650-replay-basics.sh
index 307101eeb911f7..a03f8f9293eb12 100755
--- a/t/t3650-replay-basics.sh
+++ b/t/t3650-replay-basics.sh
@@ -25,6 +25,8 @@ test_expect_success 'setup' '
 	git switch -c topic3 &&
 	test_commit G &&
 	test_commit H &&
+	git switch -c empty &&
+	git commit --allow-empty -m empty &&
 	git switch -c topic4 main &&
 	test_commit I &&
 	test_commit J &&
@@ -160,6 +162,25 @@ test_expect_success 'using replay on bare repo to perform basic cherry-pick' '
 	test_cmp expect result-bare
 '
 
+test_expect_success 'commits that become empty are dropped' '
+	# Save original branches
+	git for-each-ref --format="update %(refname) %(objectname)" \
+		refs/heads/ >original-branches &&
+	test_when_finished "git update-ref --stdin <original-branches &&
+		rm original-branches" &&
+	# Cherry-pick tip of topic1 ("F"), from the middle of A..empty, to main
+	git replay --advance main topic1^! &&
+
+	# Replay all of A..empty onto main (which includes topic1 & thus F
+	# in the middle)
+	git replay --onto main --branches --ancestry-path=empty ^A \
+		>result &&
+	git log --format="%s%d" L..empty >actual &&
+	test_write_lines >expect \
+		"empty (empty)" "H (topic3)" G "C (topic1)" "F (main)" "M (tag: M)" &&
+	test_cmp expect actual
+'
+
 test_expect_success 'replay on bare repo fails with both --advance and --onto' '
 	test_must_fail git -C bare replay --advance main --onto main topic1..topic2 >result-bare
 '
@@ -249,6 +270,15 @@ test_expect_success 'using replay on bare repo to rebase multiple divergent bran
 	done
 '
 
+test_expect_success 'using replay to update detached HEAD' '
+	current_head=$(git branch --show-current) &&
+	test_when_finished git switch "$current_head" &&
+	git switch --detach &&
+	test_commit something &&
+	git replay --ref-action=print --onto HEAD~2 --ref-action=print HEAD~..HEAD >updates &&
+	test_grep "update HEAD " updates
+'
+
 test_expect_success 'merge.directoryRenames=false' '
 	# create a test case that stress-tests the rename caching
 	git switch -c rename-onto &&
diff --git a/t/t5510-fetch.sh b/t/t5510-fetch.sh
index ce1c23684ece38..c69afb5a609343 100755
--- a/t/t5510-fetch.sh
+++ b/t/t5510-fetch.sh
@@ -1516,7 +1516,7 @@ test_expect_success REFFILES 'existing reference lock in repo' '
 		git remote add origin ../base &&
 		touch refs/heads/foo.lock &&
 		test_must_fail git fetch -f origin "refs/heads/*:refs/heads/*" 2>err &&
-		test_grep "error: fetching ref refs/heads/foo failed: reference already exists" err &&
+		test_grep -e "error: cannot lock ref ${SQ}refs/heads/foo${SQ}: Unable to create" -e "refs/heads/foo.lock${SQ}: File exists." err &&
 		git rev-parse refs/heads/main >expect &&
 		git rev-parse refs/heads/branch >actual &&
 		test_cmp expect actual
@@ -1530,7 +1530,7 @@ test_expect_success CASE_INSENSITIVE_FS,REFFILES 'F/D conflict on case insensiti
 		cd case_insensitive &&
 		git remote add origin -- ../case_sensitive_fd &&
 		test_must_fail git fetch -f origin "refs/heads/*:refs/heads/*" 2>err &&
-		test_grep "failed: refname conflict" err &&
+		test_grep "cannot process ${SQ}refs/remotes/origin/foo${SQ} and ${SQ}refs/remotes/origin/foo/bar${SQ} at the same time" err &&
 		git rev-parse refs/heads/main >expect &&
 		git rev-parse refs/heads/foo/bar >actual &&
 		test_cmp expect actual
@@ -1544,7 +1544,7 @@ test_expect_success CASE_INSENSITIVE_FS,REFFILES 'D/F conflict on case insensiti
 		cd case_insensitive &&
 		git remote add origin -- ../case_sensitive_df &&
 		test_must_fail git fetch -f origin "refs/heads/*:refs/heads/*" 2>err &&
-		test_grep "failed: refname conflict" err &&
+		test_grep "cannot lock ref ${SQ}refs/remotes/origin/foo${SQ}: there is a non-empty directory ${SQ}./refs/remotes/origin/foo${SQ} blocking reference ${SQ}refs/remotes/origin/foo${SQ}" err &&
 		git rev-parse refs/heads/main >expect &&
 		git rev-parse refs/heads/Foo/bar >actual &&
 		test_cmp expect actual
@@ -1658,7 +1658,7 @@ test_expect_success REFFILES "FETCH_HEAD is updated even if ref updates fail" '
 		git remote add origin ../base &&
 		>refs/heads/foo.lock &&
 		test_must_fail git fetch -f origin "refs/heads/*:refs/heads/*" 2>err &&
-		test_grep "error: fetching ref refs/heads/foo failed: reference already exists" err &&
+		test_grep -e "error: cannot lock ref ${SQ}refs/heads/foo${SQ}: Unable to create" -e "refs/heads/foo.lock${SQ}: File exists." err &&
 		test_grep "branch ${SQ}branch${SQ} of ../base" FETCH_HEAD &&
 		test_grep "branch ${SQ}foo${SQ} of ../base" FETCH_HEAD
 	)
diff --git a/t/t5516-fetch-push.sh b/t/t5516-fetch-push.sh
index 46926e7bbd3a9a..29e2f176081561 100755
--- a/t/t5516-fetch-push.sh
+++ b/t/t5516-fetch-push.sh
@@ -1882,4 +1882,20 @@ test_expect_success 'push with F/D conflict with deletion and creation' '
 	git push testrepo :refs/heads/branch/conflict refs/heads/branch
 '
 
+test_expect_success 'pushing non-commit objects should report error' '
+	test_when_finished "rm -rf dest repo" &&
+	git init dest &&
+	git init repo &&
+
+	(
+		cd repo &&
+		test_commit --annotate test &&
+
+		tagsha=$(git rev-parse test^{tag}) &&
+		test_must_fail git push ../dest "$tagsha:refs/heads/branch" 2>err &&
+		test_grep "! \[remote rejected\] $tagsha -> branch (invalid new value provided)" err &&
+		test_grep "trying to write non-commit object $tagsha to branch ${SQ}refs/heads/branch${SQ}" err
+	)
+'
+
 test_done
diff --git a/t/unit-tests/u-string-list.c b/t/unit-tests/u-string-list.c
index a2457d7b1ec8fa..7ad84cc1cd0e8f 100644
--- a/t/unit-tests/u-string-list.c
+++ b/t/unit-tests/u-string-list.c
@@ -243,6 +243,138 @@ void test_string_list__filter(void)
 	t_string_list_clear(&list, 0);
 }
 
+static void t_string_list_has_string(
+	struct string_list *list,
+	const char *string,
+	int expected)
+{
+	int has_string = string_list_has_string(list, string);
+	cl_assert_equal_i(has_string, expected);
+}
+
+void test_string_list__has_string(void)
+{
+	struct string_list list = STRING_LIST_INIT_DUP;
+
+	t_create_string_list_dup(&list, 0, NULL);
+	t_string_list_has_string(&list, "", 0);
+
+	t_create_string_list_dup(&list, 0, "a", "b", "c", NULL);
+	t_string_list_has_string(&list, "a", 1);
+	t_string_list_has_string(&list, "b", 1);
+	t_string_list_has_string(&list, "c", 1);
+	t_string_list_has_string(&list, "d", 0);
+
+	t_string_list_clear(&list, 0);
+}
+
+static void t_string_list_insert(struct string_list *expected_strings, ...)
+{
+	struct string_list strings_to_insert = STRING_LIST_INIT_DUP;
+	struct string_list list = STRING_LIST_INIT_DUP;
+	va_list ap;
+
+	va_start(ap, expected_strings);
+	t_vcreate_string_list_dup(&strings_to_insert, 0, ap);
+	va_end(ap);
+
+	for (size_t i = 0; i < strings_to_insert.nr; i++)
+		string_list_insert(&list, strings_to_insert.items[i].string);
+
+	t_string_list_equal(&list, expected_strings);
+
+	string_list_clear(&strings_to_insert, 0);
+	string_list_clear(&list, 0);
+}
+
+void test_string_list__insert(void)
+{
+	struct string_list expected_strings = STRING_LIST_INIT_DUP;
+
+	t_create_string_list_dup(&expected_strings, 0, NULL);
+	t_string_list_insert(&expected_strings, NULL);
+
+	t_create_string_list_dup(&expected_strings, 0, "a", "b", NULL);
+	t_string_list_insert(&expected_strings, "b", "a", "a", "b", NULL);
+
+	t_create_string_list_dup(&expected_strings, 0, "a", "b", "c", NULL);
+	t_string_list_insert(&expected_strings, "c", "b", "a", "c", "b", NULL);
+
+	t_create_string_list_dup(&expected_strings, 0, "", "a", NULL);
+	t_string_list_insert(&expected_strings, "a", "a", "a", "", NULL);
+
+	t_string_list_clear(&expected_strings, 0);
+}
+
+static void t_string_list_sort(struct string_list *list, ...)
+{
+	struct string_list expected_strings = STRING_LIST_INIT_DUP;
+	va_list ap;
+
+	va_start(ap, list);
+	t_vcreate_string_list_dup(&expected_strings, 0, ap);
+	va_end(ap);
+
+	string_list_sort(list);
+	t_string_list_equal(list, &expected_strings);
+
+	string_list_clear(&expected_strings, 0);
+}
+
+void test_string_list__sort(void)
+{
+	struct string_list list = STRING_LIST_INIT_DUP;
+
+	t_create_string_list_dup(&list, 0, NULL);
+	t_string_list_sort(&list, NULL);
+
+	t_create_string_list_dup(&list, 0, "b", "", "a", NULL);
+	t_string_list_sort(&list, "", "a", "b", NULL);
+
+	t_create_string_list_dup(&list, 0, "c", "a", "b", "a", NULL);
+	t_string_list_sort(&list, "a", "a", "b", "c", NULL);
+
+	t_string_list_clear(&list, 0);
+}
+
+static void t_string_list_remove(
+	struct string_list *expected_strings,
+	struct string_list *list,
+	char const *str)
+{
+	string_list_remove(list, str, 0);
+	t_string_list_equal(list, expected_strings);
+}
+
+void test_string_list__remove(void)
+{
+	struct string_list expected_strings = STRING_LIST_INIT_DUP;
+	struct string_list list = STRING_LIST_INIT_DUP;
+
+	t_create_string_list_dup(&expected_strings, 0, NULL);
+	t_create_string_list_dup(&list, 0, NULL);
+	t_string_list_remove(&expected_strings, &list, "");
+
+	t_create_string_list_dup(&expected_strings, 0, "a", NULL);
+	t_create_string_list_dup(&list, 0, "a", "a", NULL);
+	t_string_list_remove(&expected_strings, &list, "a");
+
+	t_create_string_list_dup(&expected_strings, 0, "a", "b", "b", NULL);
+	t_create_string_list_dup(&list, 0, "a", "b", "b", "c", NULL);
+	t_string_list_remove(&expected_strings, &list, "c");
+
+	t_create_string_list_dup(&expected_strings, 0, "a", "b", "d", NULL);
+	t_create_string_list_dup(&list, 0, "a", "b", "c", "d", NULL);
+	t_string_list_remove(&expected_strings, &list, "c");
+
+	t_create_string_list_dup(&expected_strings, 0, "a", "b", "c", "d", NULL);
+	t_create_string_list_dup(&list, 0, "a", "b", "c", "d", NULL);
+	t_string_list_remove(&expected_strings, &list, "e");
+
+	t_string_list_clear(&expected_strings, 0);
+	t_string_list_clear(&list, 0);
+}
+
 static void t_string_list_remove_duplicates(struct string_list *list, ...)
 {
 	struct string_list expected_strings = STRING_LIST_INIT_DUP;
@@ -304,3 +436,114 @@ void test_string_list__remove_duplicates(void)
 
 	t_string_list_clear(&list, 0);
 }
+
+static void t_string_list_sort_u(struct string_list *list, ...)
+{
+	struct string_list expected_strings = STRING_LIST_INIT_DUP;
+	va_list ap;
+
+	va_start(ap, list);
+	t_vcreate_string_list_dup(&expected_strings, 0, ap);
+	va_end(ap);
+
+	string_list_sort_u(list, 0);
+	t_string_list_equal(list, &expected_strings);
+
+	string_list_clear(&expected_strings, 0);
+}
+
+void test_string_list__sort_u(void)
+{
+	struct string_list list = STRING_LIST_INIT_DUP;
+
+	t_create_string_list_dup(&list, 0, NULL);
+	t_string_list_sort_u(&list, NULL);
+
+	t_create_string_list_dup(&list, 0, "", "", "", "", NULL);
+	t_string_list_sort_u(&list, "", NULL);
+
+	t_create_string_list_dup(&list, 0, "b", "a", "a", "", NULL);
+	t_string_list_sort_u(&list, "", "a", "b", NULL);
+
+	t_create_string_list_dup(&list, 0, "b", "a", "a", "d", "c", "c", NULL);
+	t_string_list_sort_u(&list, "a", "b", "c", "d", NULL);
+
+	t_string_list_clear(&list, 0);
+}
+
+static void t_string_list_remove_empty_items(
+	struct string_list *expected_strings,
+	struct string_list *list)
+{
+	string_list_remove_empty_items(list, 0);
+	t_string_list_equal(list, expected_strings);
+}
+
+void test_string_list__remove_empty_items(void)
+{
+	struct string_list expected_strings = STRING_LIST_INIT_DUP;
+	struct string_list list = STRING_LIST_INIT_DUP;
+
+	t_create_string_list_dup(&expected_strings, 0, NULL);
+	t_create_string_list_dup(&list, 0, "", "", "", NULL);
+	t_string_list_remove_empty_items(&expected_strings, &list);
+
+	t_create_string_list_dup(&expected_strings, 0, "a", "b", NULL);
+	t_create_string_list_dup(&list, 0, "a", "", "b", "", NULL);
+	t_string_list_remove_empty_items(&expected_strings, &list);
+
+	t_string_list_clear(&expected_strings, 0);
+	t_string_list_clear(&list, 0);
+}
+
+static void t_string_list_unsorted_string_list_has_string(
+	struct string_list *list,
+	const char *str, int expected)
+{
+	int has_string = unsorted_string_list_has_string(list, str);
+	cl_assert_equal_i(has_string, expected);
+}
+
+void test_string_list__unsorted_string_list_has_string(void)
+{
+	struct string_list list = STRING_LIST_INIT_DUP;
+
+	t_create_string_list_dup(&list, 0, "b", "d", "a", NULL);
+	t_string_list_unsorted_string_list_has_string(&list, "a", 1);
+	t_string_list_unsorted_string_list_has_string(&list, "b", 1);
+	t_string_list_unsorted_string_list_has_string(&list, "c", 0);
+	t_string_list_unsorted_string_list_has_string(&list, "d", 1);
+
+	t_string_list_clear(&list, 0);
+}
+
+static void t_string_list_unsorted_string_list_delete_item(
+	struct string_list *expected_list,
+	struct string_list *list,
+	int i)
+{
+	unsorted_string_list_delete_item(list, i, 0);
+
+	t_string_list_equal(list, expected_list);
+}
+
+void test_string_list__unsorted_string_list_delete_item(void)
+{
+	struct string_list expected_strings = STRING_LIST_INIT_DUP;
+	struct string_list list = STRING_LIST_INIT_DUP;
+
+	t_create_string_list_dup(&expected_strings, 0, "a", "c", "b", NULL);
+	t_create_string_list_dup(&list, 0, "a", "d", "b", "c", NULL);
+	t_string_list_unsorted_string_list_delete_item(&expected_strings, &list, 1);
+
+	t_create_string_list_dup(&expected_strings, 0, NULL);
+	t_create_string_list_dup(&list, 0, "", NULL);
+	t_string_list_unsorted_string_list_delete_item(&expected_strings, &list, 0);
+
+	t_create_string_list_dup(&expected_strings, 0, "a", "d", "c", "b", NULL);
+	t_create_string_list_dup(&list, 0,  "a", "d", "c", "b", "d", NULL);
+	t_string_list_unsorted_string_list_delete_item(&expected_strings, &list, 4);
+
+	t_string_list_clear(&expected_strings, 0);
+	t_string_list_clear(&list, 0);
+}
diff --git a/wt-status.c b/wt-status.c
index e12adb26b9f8eb..95942399f8cec6 100644
--- a/wt-status.c
+++ b/wt-status.c
@@ -612,6 +612,30 @@ static void wt_status_collect_updated_cb(struct diff_queue_struct *q,
 	}
 }
 
+void wt_status_collect_changes_trees(struct wt_status *s,
+				     const struct object_id *old_treeish,
+				     const struct object_id *new_treeish)
+{
+	struct diff_options opts = { 0 };
+
+	repo_diff_setup(s->repo, &opts);
+	opts.output_format = DIFF_FORMAT_CALLBACK;
+	opts.format_callback = wt_status_collect_updated_cb;
+	opts.format_callback_data = s;
+	opts.detect_rename = s->detect_rename >= 0 ? s->detect_rename : opts.detect_rename;
+	opts.rename_limit = s->rename_limit >= 0 ? s->rename_limit : opts.rename_limit;
+	opts.rename_score = s->rename_score >= 0 ? s->rename_score : opts.rename_score;
+	opts.flags.recursive = 1;
+	diff_setup_done(&opts);
+
+	diff_tree_oid(old_treeish, new_treeish, "", &opts);
+	diffcore_std(&opts);
+	diff_flush(&opts);
+	wt_status_get_state(s->repo, &s->state, 0);
+
+	diff_free(&opts);
+}
+
 static void wt_status_collect_changes_worktree(struct wt_status *s)
 {
 	struct rev_info rev;
diff --git a/wt-status.h b/wt-status.h
index e40a27214a700d..e9fe32e98cc18c 100644
--- a/wt-status.h
+++ b/wt-status.h
@@ -153,6 +153,15 @@ void wt_status_add_cut_line(struct wt_status *s);
 void wt_status_prepare(struct repository *r, struct wt_status *s);
 void wt_status_print(struct wt_status *s);
 void wt_status_collect(struct wt_status *s);
+
+/*
+ * Collect all changes between the two trees. Changes will be displayed as if
+ * they were staged into the index.
+ */
+void wt_status_collect_changes_trees(struct wt_status *s,
+				     const struct object_id *old_treeish,
+				     const struct object_id *new_treeish);
+
 /*
  * Frees the buffers allocated by wt_status_collect.
  */