diff --git a/Documentation/RelNotes/2.41.0.txt b/Documentation/RelNotes/2.41.0.txt
index e177aff2d0..c77484c6b5 100644
--- a/Documentation/RelNotes/2.41.0.txt
+++ b/Documentation/RelNotes/2.41.0.txt
@@ -3,7 +3,7 @@ Git v2.41 Release Notes
 
 UI, Workflows & Features
 
- * Allow information carried on the WWW-AUthenticate header to be
+ * Allow information carried on the WWW-Authenticate header to be
    passed to the credential helpers.
 
  * A new "fetch.hideRefs" option can be used to exclude specified refs
@@ -48,7 +48,7 @@ UI, Workflows & Features
 
  * "git clone" from an empty repository learned to propagate the
    choice of the hash algorithm from the source repository to the
-   newly created repository.
+   newly created repository over any one of the v0/v1/v2 protocol.
 
  * "git mergetool" and "git difftool" learns a new configuration
    guiDefault to optionally favor configured guitool over non-gui-tool
@@ -113,6 +113,10 @@ UI, Workflows & Features
  * "git fetch" learned the "--porcelain" option that emits what it did
    in a machine-parseable format.
 
+ * "git --attr-source=<tree> cmd $args" is a new way to have any
+   command to read attributes not from the working tree but from the
+   given tree object.
+
 
 Performance, Internal Implementation, Development Support etc.
 
@@ -365,6 +369,10 @@ Fixes since v2.40
     by git forges to disable replace-refs feature.
    (merge b6551feadf ds/merge-tree-use-config later to maint).
 
+ * A few bugs in the sequencer machinery that results in miscounting
+   the steps have been corrected.
+   (merge 170eea9750 js/rebase-count-fixes later to maint).
+
  * Other code cleanup, docfix, build fix, etc.
    (merge f7111175df as/doc-markup-fix later to maint).
    (merge 90ff7c9898 fc/test-aggregation-clean-up later to maint).
diff --git a/Documentation/config/http.txt b/Documentation/config/http.txt
index afeeccfbfa..51a70781e5 100644
--- a/Documentation/config/http.txt
+++ b/Documentation/config/http.txt
@@ -246,8 +246,9 @@ significantly since the entire buffer is allocated even for small
 pushes.
 
 http.lowSpeedLimit, http.lowSpeedTime::
-	If the HTTP transfer speed is less than 'http.lowSpeedLimit'
-	for longer than 'http.lowSpeedTime' seconds, the transfer is aborted.
+	If the HTTP transfer speed, in bytes per second, is less than
+	'http.lowSpeedLimit' for longer than 'http.lowSpeedTime' seconds,
+	the transfer is aborted.
 	Can be overridden by the `GIT_HTTP_LOW_SPEED_LIMIT` and
 	`GIT_HTTP_LOW_SPEED_TIME` environment variables.
 
diff --git a/Documentation/git.txt b/Documentation/git.txt
index 54b043899f..f0cafa2290 100644
--- a/Documentation/git.txt
+++ b/Documentation/git.txt
@@ -212,6 +212,11 @@ If you just want to run git as if it was started in `<path>` then use
 	nohelpers (exclude helper commands), alias and config
 	(retrieve command list from config variable completion.commands)
 
+--attr-source=<tree-ish>::
+	Read gitattributes from <tree-ish> instead of the worktree. See
+	linkgit:gitattributes[5]. This is equivalent to setting the
+	`GIT_ATTR_SOURCE` environment variable.
+
 GIT COMMANDS
 ------------
 
@@ -686,6 +691,9 @@ for further details.
 	tells Git not to verify the SSL certificate when fetching or
 	pushing over HTTPS.
 
+`GIT_ATTR_SOURCE`::
+	Sets the treeish that gitattributes will be read from.
+
 `GIT_ASKPASS`::
 	If this environment variable is set, then Git commands which need to
 	acquire passwords or passphrases (e.g. for HTTP or IMAP authentication)
diff --git a/GIT-VERSION-GEN b/GIT-VERSION-GEN
index 9a1111af9b..85d7d7a2f4 100755
--- a/GIT-VERSION-GEN
+++ b/GIT-VERSION-GEN
@@ -1,7 +1,7 @@
 #!/bin/sh
 
 GVF=GIT-VERSION-FILE
-DEF_VER=v2.40.GIT
+DEF_VER=v2.41.0-rc1
 
 LF='
 '
diff --git a/archive.c b/archive.c
index 641baad627..2ea9cbef92 100644
--- a/archive.c
+++ b/archive.c
@@ -130,7 +130,7 @@ static const struct attr_check *get_archive_attrs(struct index_state *istate,
 	static struct attr_check *check;
 	if (!check)
 		check = attr_check_initl("export-ignore", "export-subst", NULL);
-	git_check_attr(istate, NULL, path, check);
+	git_check_attr(istate, path, check);
 	return check;
 }
 
diff --git a/attr.c b/attr.c
index ddf2b0cbc2..d45d34058d 100644
--- a/attr.c
+++ b/attr.c
@@ -21,6 +21,7 @@
 #include "setup.h"
 #include "thread-utils.h"
 #include "tree-walk.h"
+#include "object-name.h"
 
 const char git_attr__true[] = "(builtin)true";
 const char git_attr__false[] = "\0(builtin)false";
@@ -1170,11 +1171,42 @@ static void collect_some_attrs(struct index_state *istate,
 	fill(path, pathlen, basename_offset, check->stack, check->all_attrs, rem);
 }
 
+static const char *default_attr_source_tree_object_name;
+
+void set_git_attr_source(const char *tree_object_name)
+{
+	default_attr_source_tree_object_name = xstrdup(tree_object_name);
+}
+
+static void compute_default_attr_source(struct object_id *attr_source)
+{
+	if (!default_attr_source_tree_object_name)
+		default_attr_source_tree_object_name = getenv(GIT_ATTR_SOURCE_ENVIRONMENT);
+
+	if (!default_attr_source_tree_object_name || !is_null_oid(attr_source))
+		return;
+
+	if (repo_get_oid_treeish(the_repository, default_attr_source_tree_object_name, attr_source))
+		die(_("bad --attr-source or GIT_ATTR_SOURCE"));
+}
+
+static struct object_id *default_attr_source(void)
+{
+	static struct object_id attr_source;
+
+	if (is_null_oid(&attr_source))
+		compute_default_attr_source(&attr_source);
+	if (is_null_oid(&attr_source))
+		return NULL;
+	return &attr_source;
+}
+
 void git_check_attr(struct index_state *istate,
-		    const struct object_id *tree_oid, const char *path,
+		    const char *path,
 		    struct attr_check *check)
 {
 	int i;
+	const struct object_id *tree_oid = default_attr_source();
 
 	collect_some_attrs(istate, tree_oid, path, check);
 
@@ -1187,10 +1219,11 @@ void git_check_attr(struct index_state *istate,
 	}
 }
 
-void git_all_attrs(struct index_state *istate, const struct object_id *tree_oid,
+void git_all_attrs(struct index_state *istate,
 		   const char *path, struct attr_check *check)
 {
 	int i;
+	const struct object_id *tree_oid = default_attr_source();
 
 	attr_check_reset(check);
 	collect_some_attrs(istate, tree_oid, path, check);
diff --git a/attr.h b/attr.h
index 9884ea2bc6..676bd17ce2 100644
--- a/attr.h
+++ b/attr.h
@@ -45,7 +45,7 @@
  * const char *path;
  *
  * setup_check();
- * git_check_attr(&the_index, tree_oid, path, check);
+ * git_check_attr(&the_index, path, check);
  * ------------
  *
  * - Act on `.value` member of the result, left in `check->items[]`:
@@ -120,7 +120,6 @@
 #define ATTR_MAX_FILE_SIZE (100 * 1024 * 1024)
 
 struct index_state;
-struct object_id;
 
 /**
  * An attribute is an opaque object that is identified by its name. Pass the
@@ -135,6 +134,12 @@ struct git_attr;
 struct all_attrs_item;
 struct attr_stack;
 
+/*
+ * The textual object name for the tree-ish used by git_check_attr()
+ * to read attributes from (instead of from the working tree).
+ */
+void set_git_attr_source(const char *);
+
 /*
  * Given a string, return the gitattribute object that
  * corresponds to it.
@@ -203,14 +208,14 @@ void attr_check_free(struct attr_check *check);
 const char *git_attr_name(const struct git_attr *);
 
 void git_check_attr(struct index_state *istate,
-		    const struct object_id *tree_oid, const char *path,
+		    const char *path,
 		    struct attr_check *check);
 
 /*
  * Retrieve all attributes that apply to the specified path.
  * check holds the attributes and their values.
  */
-void git_all_attrs(struct index_state *istate, const struct object_id *tree_oid,
+void git_all_attrs(struct index_state *istate,
 		   const char *path, struct attr_check *check);
 
 enum git_attr_direction {
diff --git a/builtin/check-attr.c b/builtin/check-attr.c
index b2b678847f..e27b86d150 100644
--- a/builtin/check-attr.c
+++ b/builtin/check-attr.c
@@ -64,7 +64,7 @@ static void output_attr(struct attr_check *check, const char *file)
 }
 
 static void check_attr(const char *prefix, struct attr_check *check,
-		       const struct object_id *tree_oid, int collect_all,
+		       int collect_all,
 		       const char *file)
 
 {
@@ -72,9 +72,9 @@ static void check_attr(const char *prefix, struct attr_check *check,
 		prefix_path(prefix, prefix ? strlen(prefix) : 0, file);
 
 	if (collect_all) {
-		git_all_attrs(&the_index, tree_oid, full_path, check);
+		git_all_attrs(&the_index, full_path, check);
 	} else {
-		git_check_attr(&the_index, tree_oid, full_path, check);
+		git_check_attr(&the_index, full_path, check);
 	}
 	output_attr(check, file);
 
@@ -82,7 +82,7 @@ static void check_attr(const char *prefix, struct attr_check *check,
 }
 
 static void check_attr_stdin_paths(const char *prefix, struct attr_check *check,
-				   const struct object_id *tree_oid, int collect_all)
+				   int collect_all)
 {
 	struct strbuf buf = STRBUF_INIT;
 	struct strbuf unquoted = STRBUF_INIT;
@@ -96,7 +96,7 @@ static void check_attr_stdin_paths(const char *prefix, struct attr_check *check,
 				die("line is badly quoted");
 			strbuf_swap(&buf, &unquoted);
 		}
-		check_attr(prefix, check, tree_oid, collect_all, buf.buf);
+		check_attr(prefix, check, collect_all, buf.buf);
 		maybe_flush_or_die(stdout, "attribute to stdout");
 	}
 	strbuf_release(&buf);
@@ -112,7 +112,6 @@ static NORETURN void error_with_usage(const char *msg)
 int cmd_check_attr(int argc, const char **argv, const char *prefix)
 {
 	struct attr_check *check;
-	struct object_id *tree_oid = NULL;
 	struct object_id initialized_oid;
 	int cnt, i, doubledash, filei;
 
@@ -188,14 +187,14 @@ int cmd_check_attr(int argc, const char **argv, const char *prefix)
 	if (source) {
 		if (repo_get_oid_tree(the_repository, source, &initialized_oid))
 			die("%s: not a valid tree-ish source", source);
-		tree_oid = &initialized_oid;
+		set_git_attr_source(source);
 	}
 
 	if (stdin_paths)
-		check_attr_stdin_paths(prefix, check, tree_oid, all_attrs);
+		check_attr_stdin_paths(prefix, check, all_attrs);
 	else {
 		for (i = filei; i < argc; i++)
-			check_attr(prefix, check, tree_oid, all_attrs, argv[i]);
+			check_attr(prefix, check, all_attrs, argv[i]);
 		maybe_flush_or_die(stdout, "attribute to stdout");
 	}
 
diff --git a/builtin/pack-objects.c b/builtin/pack-objects.c
index a5b466839b..9cfc8801f9 100644
--- a/builtin/pack-objects.c
+++ b/builtin/pack-objects.c
@@ -1331,7 +1331,7 @@ static int no_try_delta(const char *path)
 
 	if (!check)
 		check = attr_check_initl("delta", NULL);
-	git_check_attr(the_repository->index, NULL, path, check);
+	git_check_attr(the_repository->index, path, check);
 	if (ATTR_FALSE(check->items[0].value))
 		return 1;
 	return 0;
diff --git a/convert.c b/convert.c
index 7cf7bd0c88..9ee79fe469 100644
--- a/convert.c
+++ b/convert.c
@@ -1315,7 +1315,7 @@ void convert_attrs(struct index_state *istate,
 		git_config(read_convert_config, NULL);
 	}
 
-	git_check_attr(istate, NULL, path, check);
+	git_check_attr(istate, path, check);
 	ccheck = check->items;
 	ca->crlf_action = git_path_check_crlf(ccheck + 4);
 	if (ca->crlf_action == CRLF_UNDEFINED)
diff --git a/environment.h b/environment.h
index a63f0c6a24..30cb7e0fa3 100644
--- a/environment.h
+++ b/environment.h
@@ -55,6 +55,7 @@ const char *getenv_safe(struct strvec *argv, const char *name);
 #define GIT_QUARANTINE_ENVIRONMENT "GIT_QUARANTINE_PATH"
 #define GIT_OPTIONAL_LOCKS_ENVIRONMENT "GIT_OPTIONAL_LOCKS"
 #define GIT_TEXT_DOMAIN_DIR_ENVIRONMENT "GIT_TEXTDOMAINDIR"
+#define GIT_ATTR_SOURCE_ENVIRONMENT "GIT_ATTR_SOURCE"
 
 /*
  * Environment variable used in handshaking the wire protocol.
diff --git a/git-send-email.perl b/git-send-email.perl
index 89d8237e89..affbb88509 100755
--- a/git-send-email.perl
+++ b/git-send-email.perl
@@ -1788,6 +1788,7 @@ sub pre_process_file {
 	$subject = $initial_subject;
 	$message = "";
 	$message_num++;
+	undef $message_id;
 	# Retrieve and unfold header fields.
 	my @header_lines = ();
 	while(<$fh>) {
diff --git a/git.c b/git.c
index 45899be826..2f42da20f4 100644
--- a/git.c
+++ b/git.c
@@ -9,6 +9,7 @@
 #include "alias.h"
 #include "replace-object.h"
 #include "setup.h"
+#include "attr.h"
 #include "shallow.h"
 #include "trace.h"
 #include "trace2.h"
@@ -314,6 +315,21 @@ static int handle_options(const char ***argv, int *argc, int *envchanged)
 			} else {
 				exit(list_cmds(cmd));
 			}
+		} else if (!strcmp(cmd, "--attr-source")) {
+			if (*argc < 2) {
+				fprintf(stderr, _("no attribute source given for --attr-source\n" ));
+				usage(git_usage_string);
+			}
+			setenv(GIT_ATTR_SOURCE_ENVIRONMENT, (*argv)[1], 1);
+			if (envchanged)
+				*envchanged = 1;
+			(*argv)++;
+			(*argc)--;
+		} else if (skip_prefix(cmd, "--attr-source=", &cmd)) {
+			set_git_attr_source(cmd);
+			setenv(GIT_ATTR_SOURCE_ENVIRONMENT, cmd, 1);
+			if (envchanged)
+				*envchanged = 1;
 		} else {
 			fprintf(stderr, _("unknown option: %s\n"), cmd);
 			usage(git_usage_string);
diff --git a/imap-send.c b/imap-send.c
index a62424e90a..7f5426177a 100644
--- a/imap-send.c
+++ b/imap-send.c
@@ -29,6 +29,7 @@
 #include "run-command.h"
 #include "parse-options.h"
 #include "setup.h"
+#include "strbuf.h"
 #include "wrapper.h"
 #if defined(NO_OPENSSL) && !defined(HAVE_OPENSSL_CSPRNG)
 typedef void *SSL;
diff --git a/ll-merge.c b/ll-merge.c
index 1993530688..07ec16e8e5 100644
--- a/ll-merge.c
+++ b/ll-merge.c
@@ -394,7 +394,7 @@ enum ll_merge_result ll_merge(mmbuffer_t *result_buf,
 		normalize_file(theirs, path, istate);
 	}
 
-	git_check_attr(istate, NULL, path, check);
+	git_check_attr(istate, path, check);
 	ll_driver_name = check->items[0].value;
 	if (check->items[1].value) {
 		marker_size = atoi(check->items[1].value);
@@ -422,7 +422,7 @@ int ll_merge_marker_size(struct index_state *istate, const char *path)
 
 	if (!check)
 		check = attr_check_initl("conflict-marker-size", NULL);
-	git_check_attr(istate, NULL, path, check);
+	git_check_attr(istate, path, check);
 	if (check->items[0].value) {
 		marker_size = atoi(check->items[0].value);
 		if (marker_size <= 0)
diff --git a/pathspec.c b/pathspec.c
index 1e57b6c667..6966b265d3 100644
--- a/pathspec.c
+++ b/pathspec.c
@@ -736,7 +736,7 @@ int match_pathspec_attrs(struct index_state *istate,
 	if (name[namelen])
 		name = to_free = xmemdupz(name, namelen);
 
-	git_check_attr(istate, NULL, name, item->attr_check);
+	git_check_attr(istate, name, item->attr_check);
 
 	free(to_free);
 
diff --git a/run-command.c b/run-command.c
index d4247d5fcc..60c9419866 100644
--- a/run-command.c
+++ b/run-command.c
@@ -16,6 +16,7 @@
 #include "packfile.h"
 #include "hook.h"
 #include "compat/nonblock.h"
+#include "alloc.h"
 
 void child_process_init(struct child_process *child)
 {
diff --git a/sequencer.c b/sequencer.c
index b553b49fbb..bceb6abcb6 100644
--- a/sequencer.c
+++ b/sequencer.c
@@ -2477,7 +2477,6 @@ void todo_list_release(struct todo_list *todo_list)
 static struct todo_item *append_new_todo(struct todo_list *todo_list)
 {
 	ALLOC_GROW(todo_list->items, todo_list->nr + 1, todo_list->alloc);
-	todo_list->total_nr++;
 	return todo_list->items + todo_list->nr++;
 }
 
@@ -2668,7 +2667,7 @@ int todo_list_parse_insn_buffer(struct repository *r, char *buf,
 	char *p = buf, *next_p;
 	int i, res = 0, fixup_okay = file_exists(rebase_path_done());
 
-	todo_list->current = todo_list->nr = 0;
+	todo_list->current = todo_list->nr = todo_list->total_nr = 0;
 
 	for (i = 1; *p; i++, p = next_p) {
 		char *eol = strchrnul(p, '\n');
@@ -2689,6 +2688,9 @@ int todo_list_parse_insn_buffer(struct repository *r, char *buf,
 			item->commit = NULL;
 		}
 
+		if (item->command != TODO_COMMENT)
+			todo_list->total_nr++;
+
 		if (fixup_okay)
 			; /* do nothing */
 		else if (is_fixup(item->command))
@@ -4270,7 +4272,7 @@ void todo_list_filter_update_refs(struct repository *r,
 		if (!is_null_oid(&rec->after))
 			continue;
 
-		for (j = 0; !found && j < todo_list->total_nr; j++) {
+		for (j = 0; !found && j < todo_list->nr; j++) {
 			struct todo_item *item = &todo_list->items[j];
 			const char *arg = todo_list->buf.buf + item->arg_offset;
 
@@ -4300,7 +4302,7 @@ void todo_list_filter_update_refs(struct repository *r,
 	 * For each todo_item, check if its ref is in the update_refs list.
 	 * If not, then add it as an un-updated ref.
 	 */
-	for (i = 0; i < todo_list->total_nr; i++) {
+	for (i = 0; i < todo_list->nr; i++) {
 		struct todo_item *item = &todo_list->items[i];
 		const char *arg = todo_list->buf.buf + item->arg_offset;
 		int j, found = 0;
@@ -6148,7 +6150,8 @@ int complete_action(struct repository *r, struct replay_opts *opts, unsigned fla
 	todo_list_to_strbuf(r, &new_todo, &buf2, -1, 0);
 	strbuf_swap(&new_todo.buf, &buf2);
 	strbuf_release(&buf2);
-	new_todo.total_nr -= new_todo.nr;
+	/* Nothing is done yet, and we're reparsing, so let's reset the count */
+	new_todo.total_nr = 0;
 	if (todo_list_parse_insn_buffer(r, new_todo.buf.buf, &new_todo) < 0)
 		BUG("invalid todo list after expanding IDs:\n%s",
 		    new_todo.buf.buf);
diff --git a/t/lib-diff-alternative.sh b/t/lib-diff-alternative.sh
index a8f5d3274a..c4dc2d46dc 100644
--- a/t/lib-diff-alternative.sh
+++ b/t/lib-diff-alternative.sh
@@ -112,15 +112,36 @@ EOF
 
 	STRATEGY=$1
 
-	test_expect_success "$STRATEGY diff from attributes" '
+	test_expect_success "setup attributes files for tests with $STRATEGY" '
+		git checkout -b master &&
 		echo "file* diff=driver" >.gitattributes &&
-		git config diff.driver.algorithm "$STRATEGY" &&
-		test_must_fail git diff --no-index file1 file2 > output &&
-		cat expect &&
-		cat output &&
+		git add file1 file2 .gitattributes &&
+		git commit -m "adding files" &&
+		git checkout -b branchA &&
+		echo "file* diff=driverA" >.gitattributes &&
+		git add .gitattributes &&
+		git commit -m "adding driverA as diff driver" &&
+		git checkout master &&
+		git clone --bare --no-local . bare.git
+	'
+
+	test_expect_success "$STRATEGY diff from attributes" '
+		test_must_fail git -c diff.driver.algorithm=$STRATEGY diff --no-index file1 file2 > output &&
 		test_cmp expect output
 	'
 
+	test_expect_success "diff from attributes with bare repo with source" '
+		git -C bare.git --attr-source=branchA -c diff.driver.algorithm=myers \
+			-c diff.driverA.algorithm=$STRATEGY \
+			diff HEAD:file1 HEAD:file2 >output &&
+		test_cmp expect output
+	'
+
+	test_expect_success "diff from attributes with bare repo with invalid source" '
+		test_must_fail git -C bare.git --attr-source=invalid-branch diff \
+			HEAD:file1 HEAD:file2
+	'
+
 	test_expect_success "$STRATEGY diff from attributes has valid diffstat" '
 		echo "file* diff=driver" >.gitattributes &&
 		git config diff.driver.algorithm "$STRATEGY" &&
diff --git a/t/lib-httpd.sh b/t/lib-httpd.sh
index 6805229dcb..2fb1b2ae56 100644
--- a/t/lib-httpd.sh
+++ b/t/lib-httpd.sh
@@ -191,6 +191,20 @@ enable_http2 () {
 	test_set_prereq HTTP2
 }
 
+enable_cgipassauth () {
+	# We are looking for 2.4.13 or more recent. Since we only support
+	# 2.4 and up, no need to check for older major/minor.
+	if test "$HTTPD_VERSION_MAJOR" = 2 &&
+	   test "$HTTPD_VERSION_MINOR" = 4 &&
+	   test "$(echo $HTTPD_VERSION | cut -d. -f3)" -lt 13
+	then
+		echo >&4 "apache $HTTPD_VERSION too old for CGIPassAuth"
+		return
+	fi
+	HTTPD_PARA="$HTTPD_PARA -DUSE_CGIPASSAUTH"
+	test_set_prereq CGIPASSAUTH
+}
+
 start_httpd() {
 	prepare_httpd >&3 2>&4
 
diff --git a/t/lib-httpd/apache.conf b/t/lib-httpd/apache.conf
index 9e6892970d..a22d138605 100644
--- a/t/lib-httpd/apache.conf
+++ b/t/lib-httpd/apache.conf
@@ -146,7 +146,9 @@ SetEnv PERL_PATH ${PERL_PATH}
 <LocationMatch /custom_auth/>
 	SetEnv GIT_EXEC_PATH ${GIT_EXEC_PATH}
 	SetEnv GIT_HTTP_EXPORT_ALL
+	<IfDefine USE_CGIPASSAUTH>
 	CGIPassAuth on
+	</IfDefine>
 </LocationMatch>
 ScriptAlias /smart/incomplete_length/git-upload-pack incomplete-length-upload-pack-v2-http.sh/
 ScriptAlias /smart/incomplete_body/git-upload-pack incomplete-body-upload-pack-v2-http.sh/
diff --git a/t/lib-submodule-update.sh b/t/lib-submodule-update.sh
index dee14992c5..9acb0d5d19 100644
--- a/t/lib-submodule-update.sh
+++ b/t/lib-submodule-update.sh
@@ -802,7 +802,7 @@ test_submodule_recursing_with_args_common () {
 			git branch -t no_submodule origin/no_submodule &&
 			$command no_submodule &&
 			test_superproject_content origin/no_submodule &&
-			! test_path_is_dir sub1 &&
+			test_path_is_missing sub1 &&
 			test_must_fail git config -f .git/modules/sub1/config core.worktree &&
 			test_must_fail git config -f .git/modules/sub1/modules/sub2/config core.worktree
 		)
diff --git a/t/t0003-attributes.sh b/t/t0003-attributes.sh
index 89b306cb11..26e082f05b 100755
--- a/t/t0003-attributes.sh
+++ b/t/t0003-attributes.sh
@@ -30,8 +30,17 @@ attr_check_quote () {
 attr_check_source () {
 	path="$1" expect="$2" source="$3" git_opts="$4" &&
 
-	git $git_opts check-attr --source $source test -- "$path" >actual 2>err &&
 	echo "$path: test: $expect" >expect &&
+
+	git $git_opts check-attr --source $source test -- "$path" >actual 2>err &&
+	test_cmp expect actual &&
+	test_must_be_empty err &&
+
+	git $git_opts --attr-source="$source" check-attr test -- "$path" >actual 2>err &&
+	test_cmp expect actual &&
+	test_must_be_empty err
+
+	GIT_ATTR_SOURCE="$source" git $git_opts check-attr test -- "$path" >actual 2>err &&
 	test_cmp expect actual &&
 	test_must_be_empty err
 }
diff --git a/t/t2021-checkout-overwrite.sh b/t/t2021-checkout-overwrite.sh
index 034f62c13c..ecfacf0f7f 100755
--- a/t/t2021-checkout-overwrite.sh
+++ b/t/t2021-checkout-overwrite.sh
@@ -77,7 +77,7 @@ test_expect_success 'checkout --overwrite-ignore should succeed if only ignored
 	echo autogenerated information >some_dir/ignore &&
 	echo ignore >.git/info/exclude &&
 	git checkout --overwrite-ignore df_conflict &&
-	! test_path_is_dir some_dir
+	test_path_is_file some_dir
 '
 
 test_done
diff --git a/t/t3430-rebase-merges.sh b/t/t3430-rebase-merges.sh
index f03599c63b..96ae0edf1e 100755
--- a/t/t3430-rebase-merges.sh
+++ b/t/t3430-rebase-merges.sh
@@ -578,4 +578,12 @@ test_expect_success '--rebase-merges with message matched with onto label' '
 	EOF
 '
 
+test_expect_success 'progress shows the correct total' '
+	git checkout -b progress H &&
+	git rebase --rebase-merges --force-rebase --verbose A 2> err &&
+	# Expecting "Rebasing (N/14)" here, no bogus total number
+	grep "^Rebasing.*/14.$" err >progress &&
+	test_line_count = 14 progress
+'
+
 test_done
diff --git a/t/t4018-diff-funcname.sh b/t/t4018-diff-funcname.sh
index 42a2b9a13b..c8d555771d 100755
--- a/t/t4018-diff-funcname.sh
+++ b/t/t4018-diff-funcname.sh
@@ -63,6 +63,25 @@ do
 		test_i18ngrep ! fatal msg &&
 		test_i18ngrep ! error msg
 	'
+
+	test_expect_success "builtin $p pattern compiles on bare repo with --attr-source" '
+		test_when_finished "rm -rf bare.git" &&
+		git checkout -B master &&
+		git add . &&
+		echo "*.java diff=notexist" >.gitattributes &&
+		git add .gitattributes &&
+		git commit -am "changing gitattributes" &&
+		git checkout -B branchA &&
+		echo "*.java diff=$p" >.gitattributes &&
+		git add .gitattributes &&
+		git commit -am "changing gitattributes" &&
+		git clone --bare --no-local . bare.git &&
+		git -C bare.git symbolic-ref HEAD refs/heads/master &&
+		test_expect_code 1 git -C bare.git --attr-source=branchA \
+			diff --exit-code HEAD:A.java HEAD:B.java 2>msg &&
+		test_i18ngrep ! fatal msg &&
+		test_i18ngrep ! error msg
+	'
 done
 
 test_expect_success 'last regexp must not be negated' '
diff --git a/t/t4067-diff-partial-clone.sh b/t/t4067-diff-partial-clone.sh
index f60f5cbd65..7af3a08862 100755
--- a/t/t4067-diff-partial-clone.sh
+++ b/t/t4067-diff-partial-clone.sh
@@ -151,7 +151,7 @@ test_expect_success 'diff does not fetch anything if inexact rename detection is
 
 	# Ensure no fetches.
 	GIT_TRACE_PACKET="$(pwd)/trace" git -C client diff --raw -M HEAD^ HEAD &&
-	! test_path_exists trace
+	test_path_is_missing trace
 '
 
 test_expect_success 'diff --break-rewrites fetches only if necessary, and batches blobs if it does' '
@@ -171,7 +171,7 @@ test_expect_success 'diff --break-rewrites fetches only if necessary, and batche
 
 	# Ensure no fetches.
 	GIT_TRACE_PACKET="$(pwd)/trace" git -C client diff --raw -M HEAD^ HEAD &&
-	! test_path_exists trace &&
+	test_path_is_missing trace &&
 
 	# But with --break-rewrites, ensure that there is exactly 1 negotiation
 	# by checking that there is only 1 "done" line sent. ("done" marks the
diff --git a/t/t4115-apply-symlink.sh b/t/t4115-apply-symlink.sh
index e95e6d4e7d..a22a90d552 100755
--- a/t/t4115-apply-symlink.sh
+++ b/t/t4115-apply-symlink.sh
@@ -74,7 +74,7 @@ test_expect_success SYMLINKS 'symlink escape when creating new files' '
 	error: affected file ${SQ}renamed-symlink/create-me${SQ} is beyond a symbolic link
 	EOF
 	test_cmp expected_stderr stderr &&
-	! test_path_exists .git/create-me
+	test_path_is_missing .git/create-me
 '
 
 test_expect_success SYMLINKS 'symlink escape when modifying file' '
diff --git a/t/t5551-http-fetch-smart.sh b/t/t5551-http-fetch-smart.sh
index 0908534f25..21b7767cbd 100755
--- a/t/t5551-http-fetch-smart.sh
+++ b/t/t5551-http-fetch-smart.sh
@@ -611,6 +611,33 @@ test_expect_success 'client falls back from v2 to v0 to match server' '
 	grep symref=HEAD:refs/heads/ trace
 '
 
+test_expect_success 'create empty http-accessible SHA-256 repository' '
+	mkdir "$HTTPD_DOCUMENT_ROOT_PATH/sha256.git" &&
+	(cd "$HTTPD_DOCUMENT_ROOT_PATH/sha256.git" &&
+	 git --bare init --object-format=sha256
+	)
+'
+
+test_expect_success 'clone empty SHA-256 repository with protocol v2' '
+	rm -fr sha256 &&
+	echo sha256 >expected &&
+	git -c protocol.version=2 clone "$HTTPD_URL/smart/sha256.git" &&
+	git -C sha256 rev-parse --show-object-format >actual &&
+	test_cmp actual expected &&
+	git ls-remote "$HTTPD_URL/smart/sha256.git" >actual &&
+	test_must_be_empty actual
+'
+
+test_expect_success 'clone empty SHA-256 repository with protocol v0' '
+	rm -fr sha256 &&
+	echo sha256 >expected &&
+	GIT_TRACE=1 GIT_TRACE_PACKET=1 git -c protocol.version=0 clone "$HTTPD_URL/smart/sha256.git" &&
+	git -C sha256 rev-parse --show-object-format >actual &&
+	test_cmp actual expected &&
+	git ls-remote "$HTTPD_URL/smart/sha256.git" >actual &&
+	test_must_be_empty actual
+'
+
 test_expect_success 'passing hostname resolution information works' '
 	BOGUS_HOST=gitbogusexamplehost.invalid &&
 	BOGUS_HTTPD_URL=$HTTPD_PROTO://$BOGUS_HOST:$LIB_HTTPD_PORT &&
diff --git a/t/t5563-simple-http-auth.sh b/t/t5563-simple-http-auth.sh
index f45a43b4b5..ab8a721ccc 100755
--- a/t/t5563-simple-http-auth.sh
+++ b/t/t5563-simple-http-auth.sh
@@ -5,6 +5,12 @@ test_description='test http auth header and credential helper interop'
 . ./test-lib.sh
 . "$TEST_DIRECTORY"/lib-httpd.sh
 
+enable_cgipassauth
+if ! test_have_prereq CGIPASSAUTH
+then
+	skip_all="no CGIPassAuth support"
+	test_done
+fi
 start_httpd
 
 test_expect_success 'setup_credential_helper' '
diff --git a/t/t5572-pull-submodule.sh b/t/t5572-pull-submodule.sh
index 09097eff3f..4e917bf87d 100755
--- a/t/t5572-pull-submodule.sh
+++ b/t/t5572-pull-submodule.sh
@@ -121,7 +121,7 @@ test_expect_success "fetch.recurseSubmodules option triggers recursive fetch (bu
 	sub_oid=$(git -C child rev-parse HEAD) &&
 	git -C super/sub cat-file -e $sub_oid &&
 	# Check that the submodule worktree did not update
-	! test_path_is_file super/sub/merge_strategy_5.t
+	test_path_is_missing super/sub/merge_strategy_5.t
 '
 
 test_expect_success "fetch.recurseSubmodules takes precedence over submodule.recurse" '
@@ -134,7 +134,7 @@ test_expect_success "fetch.recurseSubmodules takes precedence over submodule.rec
 	sub_oid=$(git -C child rev-parse HEAD) &&
 	git -C super/sub cat-file -e $sub_oid &&
 	# Check that the submodule worktree did not update
-	! test_path_is_file super/sub/merge_strategy_6.t
+	test_path_is_missing super/sub/merge_strategy_6.t
 '
 
 test_expect_success 'pull --rebase --recurse-submodules (remote superproject submodule changes, local submodule changes)' '
diff --git a/t/t5700-protocol-v1.sh b/t/t5700-protocol-v1.sh
index 6c8d4c6cf1..a73b4d4ff6 100755
--- a/t/t5700-protocol-v1.sh
+++ b/t/t5700-protocol-v1.sh
@@ -244,15 +244,28 @@ test_expect_success 'push with ssh:// using protocol v1' '
 	grep "push< version 1" log
 '
 
+test_expect_success 'clone propagates object-format from empty repo' '
+	test_when_finished "rm -fr src256 dst256" &&
+
+	echo sha256 >expect &&
+	git init --object-format=sha256 src256 &&
+	git clone --no-local src256 dst256 &&
+	git -C dst256 rev-parse --show-object-format >actual &&
+
+	test_cmp expect actual
+'
+
 # Test protocol v1 with 'http://' transport
 #
 . "$TEST_DIRECTORY"/lib-httpd.sh
 start_httpd
 
-test_expect_success 'create repo to be served by http:// transport' '
+test_expect_success 'create repos to be served by http:// transport' '
 	git init "$HTTPD_DOCUMENT_ROOT_PATH/http_parent" &&
 	git -C "$HTTPD_DOCUMENT_ROOT_PATH/http_parent" config http.receivepack true &&
-	test_commit -C "$HTTPD_DOCUMENT_ROOT_PATH/http_parent" one
+	test_commit -C "$HTTPD_DOCUMENT_ROOT_PATH/http_parent" one &&
+	git init --object-format=sha256 "$HTTPD_DOCUMENT_ROOT_PATH/sha256" &&
+	git -C "$HTTPD_DOCUMENT_ROOT_PATH/sha256" config http.receivepack true
 '
 
 test_expect_success 'clone with http:// using protocol v1' '
@@ -269,6 +282,20 @@ test_expect_success 'clone with http:// using protocol v1' '
 	grep "git< version 1" log
 '
 
+test_expect_success 'clone with http:// using protocol v1 with empty SHA-256 repo' '
+	GIT_TRACE_PACKET=1 GIT_TRACE_CURL=1 git -c protocol.version=1 \
+		clone "$HTTPD_URL/smart/sha256" sha256 2>log &&
+
+	echo sha256 >expect &&
+	git -C sha256 rev-parse --show-object-format >actual &&
+	test_cmp expect actual &&
+
+	# Client requested to use protocol v1
+	grep "Git-Protocol: version=1" log &&
+	# Server responded using protocol v1
+	grep "git< version 1" log
+'
+
 test_expect_success 'fetch with http:// using protocol v1' '
 	test_commit -C "$HTTPD_DOCUMENT_ROOT_PATH/http_parent" two &&
 
diff --git a/t/t9001-send-email.sh b/t/t9001-send-email.sh
index b77726c320..22fc908024 100755
--- a/t/t9001-send-email.sh
+++ b/t/t9001-send-email.sh
@@ -4,7 +4,7 @@ test_description='git send-email'
 GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME=main
 export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME
 
-TEST_PASSES_SANITIZE_LEAK=true
+# no longer TEST_PASSES_SANITIZE_LEAK=true - format-patch --thread leaks
 . ./test-lib.sh
 
 # May be altered later in the test
@@ -47,7 +47,7 @@ clean_fake_sendmail () {
 
 test_expect_success $PREREQ 'Extract patches' '
 	patches=$(git format-patch -s --cc="One <one@example.com>" --cc=two@example.com -n HEAD^1) &&
-	threaded_patches=$(git format-patch -o threaded -s --in-reply-to="format" HEAD^1)
+	threaded_patches=$(git format-patch -o threaded --thread=shallow -s --in-reply-to="format" HEAD^1)
 '
 
 # Test no confirm early to ensure remaining tests will not hang
@@ -655,6 +655,21 @@ test_expect_success $PREREQ "--validate hook supports header argument" '
 		outdir/000?-*.patch
 '
 
+test_expect_success $PREREQ 'clear message-id before parsing a new message' '
+	clean_fake_sendmail &&
+	echo true | write_script my-hooks/sendemail-validate &&
+	test_config core.hooksPath my-hooks &&
+	GIT_SEND_EMAIL_NOTTY=1 \
+	git send-email --validate --to=recipient@example.com \
+		--smtp-server="$(pwd)/fake.sendmail" \
+		$patches $threaded_patches &&
+	id0=$(grep "^Message-ID: " $threaded_patches) &&
+	id1=$(grep "^Message-ID: " msgtxt1) &&
+	id2=$(grep "^Message-ID: " msgtxt2) &&
+	test "z$id0" = "z$id2" &&
+	test "z$id1" != "z$id2"
+'
+
 for enc in 7bit 8bit quoted-printable base64
 do
 	test_expect_success $PREREQ "--transfer-encoding=$enc produces correct header" '
diff --git a/upload-pack.c b/upload-pack.c
index 08633dc121..d3312006a3 100644
--- a/upload-pack.c
+++ b/upload-pack.c
@@ -120,6 +120,7 @@ struct upload_pack_data {
 	unsigned allow_ref_in_want : 1;				/* v2 only */
 	unsigned allow_sideband_all : 1;			/* v2 only */
 	unsigned advertise_sid : 1;
+	unsigned sent_capabilities : 1;
 };
 
 static void upload_pack_data_init(struct upload_pack_data *data)
@@ -1206,18 +1207,17 @@ static void format_session_id(struct strbuf *buf, struct upload_pack_data *d) {
 		strbuf_addf(buf, " session-id=%s", trace2_session_id());
 }
 
-static int send_ref(const char *refname, const struct object_id *oid,
-		    int flag UNUSED, void *cb_data)
+static void write_v0_ref(struct upload_pack_data *data,
+			const char *refname, const char *refname_nons,
+			const struct object_id *oid)
 {
 	static const char *capabilities = "multi_ack thin-pack side-band"
 		" side-band-64k ofs-delta shallow deepen-since deepen-not"
 		" deepen-relative no-progress include-tag multi_ack_detailed";
-	const char *refname_nons = strip_namespace(refname);
 	struct object_id peeled;
-	struct upload_pack_data *data = cb_data;
 
 	if (mark_our_ref(refname_nons, refname, oid, &data->hidden_refs))
-		return 0;
+		return;
 
 	if (capabilities) {
 		struct strbuf symref_info = STRBUF_INIT;
@@ -1240,12 +1240,20 @@ static int send_ref(const char *refname, const struct object_id *oid,
 			     git_user_agent_sanitized());
 		strbuf_release(&symref_info);
 		strbuf_release(&session_id);
+		data->sent_capabilities = 1;
 	} else {
 		packet_fwrite_fmt(stdout, "%s %s\n", oid_to_hex(oid), refname_nons);
 	}
 	capabilities = NULL;
 	if (!peel_iterated_oid(oid, &peeled))
 		packet_fwrite_fmt(stdout, "%s %s^{}\n", oid_to_hex(&peeled), refname_nons);
+	return;
+}
+
+static int send_ref(const char *refname, const struct object_id *oid,
+		    int flag UNUSED, void *cb_data)
+{
+	write_v0_ref(cb_data, refname, strip_namespace(refname), oid);
 	return 0;
 }
 
@@ -1379,6 +1387,10 @@ void upload_pack(const int advertise_refs, const int stateless_rpc,
 			data.no_done = 1;
 		head_ref_namespaced(send_ref, &data);
 		for_each_namespaced_ref(send_ref, &data);
+		if (!data.sent_capabilities) {
+			const char *refname = "capabilities^{}";
+			write_v0_ref(&data, refname, refname, null_oid());
+		}
 		/*
 		 * fflush stdout before calling advertise_shallow_grafts because send_ref
 		 * uses stdio.
diff --git a/userdiff.c b/userdiff.c
index eaec6ebb5e..664c7c1402 100644
--- a/userdiff.c
+++ b/userdiff.c
@@ -444,7 +444,7 @@ struct userdiff_driver *userdiff_find_by_path(struct index_state *istate,
 		check = attr_check_initl("diff", NULL);
 	if (!path)
 		return NULL;
-	git_check_attr(istate, NULL, path, check);
+	git_check_attr(istate, path, check);
 
 	if (ATTR_TRUE(check->items[0].value))
 		return &driver_true;
diff --git a/ws.c b/ws.c
index d356d4ec9e..9456e2fdbe 100644
--- a/ws.c
+++ b/ws.c
@@ -83,7 +83,7 @@ unsigned whitespace_rule(struct index_state *istate, const char *pathname)
 	if (!attr_whitespace_rule)
 		attr_whitespace_rule = attr_check_initl("whitespace", NULL);
 
-	git_check_attr(istate, NULL, pathname, attr_whitespace_rule);
+	git_check_attr(istate, pathname, attr_whitespace_rule);
 	value = attr_whitespace_rule->items[0].value;
 	if (ATTR_TRUE(value)) {
 		/* true (whitespace) */