26 files changed, 638 insertions, 99 deletions

diff --git a/t/helper/test-advise.c b/t/helper/test-advise.c
new file mode 100644
index 0000000000..38cdc2884e
--- /dev/null
+++ b/t/helper/test-advise.c
@@ -0,0 +1,22 @@
+#include "test-tool.h"
+#include "cache.h"
+#include "advice.h"
+#include "config.h"
+
+int cmd__advise_if_enabled(int argc, const char **argv)
+{
+	if (!argv[1])
+	die("usage: %s <advice>", argv[0]);
+
+	setup_git_directory();
+	git_config(git_default_config, NULL);
+
+	/*
+	 * Any advice type can be used for testing, but NESTED_TAG was
+	 * selected here and in t0018 where this command is being
+	 * executed.
+	 */
+	advise_if_enabled(ADVICE_NESTED_TAG, argv[1]);
+
+	return 0;
+}
diff --git a/t/helper/test-dump-split-index.c b/t/helper/test-dump-split-index.c
index 63c689d6ee..a209880eb3 100644
--- a/t/helper/test-dump-split-index.c
+++ b/t/helper/test-dump-split-index.c
@@ -13,6 +13,8 @@ int cmd__dump_split_index(int ac, const char **av)
 	struct split_index *si;
 	int i;
 
+	setup_git_directory();
+
 	do_read_index(&the_index, av[1], 1);
 	printf("own %s\n", oid_to_hex(&the_index.oid));
 	si = the_index.split_index;
diff --git a/t/helper/test-path-utils.c b/t/helper/test-path-utils.c
index 409034cf4e..313a153209 100644
--- a/t/helper/test-path-utils.c
+++ b/t/helper/test-path-utils.c
@@ -290,11 +290,14 @@ int cmd__path_utils(int argc, const char **argv)
 	}
 
 	if (argc >= 2 && !strcmp(argv[1], "real_path")) {
+		struct strbuf realpath = STRBUF_INIT;
 		while (argc > 2) {
-			puts(real_path(argv[2]));
+			strbuf_realpath(&realpath, argv[2], 1);
+			puts(realpath.buf);
 			argc--;
 			argv++;
 		}
+		strbuf_release(&realpath);
 		return 0;
 	}
 
diff --git a/t/helper/test-repository.c b/t/helper/test-repository.c
index f7f8618445..56f0e3c1be 100644
--- a/t/helper/test-repository.c
+++ b/t/helper/test-repository.c
@@ -19,12 +19,11 @@ static void test_parse_commit_in_graph(const char *gitdir, const char *worktree,
 
 	memset(the_repository, 0, sizeof(*the_repository));
 
-	/* TODO: Needed for temporary hack in hashcmp, see 183a638b7da. */
-	repo_set_hash_algo(the_repository, GIT_HASH_SHA1);
-
 	if (repo_init(&r, gitdir, worktree))
 		die("Couldn't init repo");
 
+	repo_set_hash_algo(the_repository, hash_algo_by_ptr(r.hash_algo));
+
 	c = lookup_commit(&r, commit_oid);
 
 	if (!parse_commit_in_graph(&r, c))
@@ -50,12 +49,11 @@ static void test_get_commit_tree_in_graph(const char *gitdir,
 
 	memset(the_repository, 0, sizeof(*the_repository));
 
-	/* TODO: Needed for temporary hack in hashcmp, see 183a638b7da. */
-	repo_set_hash_algo(the_repository, GIT_HASH_SHA1);
-
 	if (repo_init(&r, gitdir, worktree))
 		die("Couldn't init repo");
 
+	repo_set_hash_algo(the_repository, hash_algo_by_ptr(r.hash_algo));
+
 	c = lookup_commit(&r, commit_oid);
 
 	/*
@@ -75,6 +73,10 @@ static void test_get_commit_tree_in_graph(const char *gitdir,
 
 int cmd__repository(int argc, const char **argv)
 {
+	int nongit_ok = 0;
+
+	setup_git_directory_gently(&nongit_ok);
+
 	if (argc < 2)
 		die("must have at least 2 arguments");
 	if (!strcmp(argv[1], "parse_commit_in_graph")) {
diff --git a/t/helper/test-tool.c b/t/helper/test-tool.c
index c9a232d238..31eedcd241 100644
--- a/t/helper/test-tool.c
+++ b/t/helper/test-tool.c
@@ -14,6 +14,7 @@ struct test_cmd {
 };
 
 static struct test_cmd cmds[] = {
+	{ "advise", cmd__advise_if_enabled },
 	{ "chmtime", cmd__chmtime },
 	{ "config", cmd__config },
 	{ "ctype", cmd__ctype },
diff --git a/t/helper/test-tool.h b/t/helper/test-tool.h
index c8549fd87f..4eb5e6609e 100644
--- a/t/helper/test-tool.h
+++ b/t/helper/test-tool.h
@@ -4,6 +4,7 @@
 #define USE_THE_INDEX_COMPATIBILITY_MACROS
 #include "git-compat-util.h"
 
+int cmd__advise_if_enabled(int argc, const char **argv);
 int cmd__chmtime(int argc, const char **argv);
 int cmd__config(int argc, const char **argv);
 int cmd__ctype(int argc, const char **argv);
diff --git a/t/lib-submodule-update.sh b/t/lib-submodule-update.sh
index 1dd17fc03e..64fc6487dd 100755
--- a/t/lib-submodule-update.sh
+++ b/t/lib-submodule-update.sh
@@ -297,7 +297,7 @@ test_submodule_content () {
 # - Directory containing tracked files replaced by submodule
 # - Submodule replaced by tracked files in directory
 # - Submodule replaced by tracked file with the same name
-# - tracked file replaced by submodule
+# - Tracked file replaced by submodule
 #
 # The default is that submodule contents aren't changed until "git submodule
 # update" is run. And even then that command doesn't delete the work tree of
@@ -621,11 +621,13 @@ test_submodule_forced_switch () {
 # - Directory containing tracked files replaced by submodule
 # - Submodule replaced by tracked files in directory
 # - Submodule replaced by tracked file with the same name
-# - tracked file replaced by submodule
+# - Tracked file replaced by submodule
 #
 # New test cases
 # - Removing a submodule with a git directory absorbs the submodules
 #   git directory first into the superproject.
+# - Switching from no submodule to nested submodules
+# - Switching from nested submodules to no submodule
 
 # Internal function; use test_submodule_switch_recursing_with_args() or
 # test_submodule_forced_switch_recursing_with_args() instead.
@@ -658,22 +660,6 @@ test_submodule_recursing_with_args_common() {
 			test_submodule_content sub1 origin/add_sub1
 		)
 	'
-	test_expect_success "$command: submodule branch is not changed, detach HEAD instead" '
-		prolog &&
-		reset_work_tree_to_interested add_sub1 &&
-		(
-			cd submodule_update &&
-			git -C sub1 checkout -b keep_branch &&
-			git -C sub1 rev-parse HEAD >expect &&
-			git branch -t modify_sub1 origin/modify_sub1 &&
-			$command modify_sub1 &&
-			test_superproject_content origin/modify_sub1 &&
-			test_submodule_content sub1 origin/modify_sub1 &&
-			git -C sub1 rev-parse keep_branch >actual &&
-			test_cmp expect actual &&
-			test_must_fail git -C sub1 symbolic-ref HEAD
-		)
-	'
 
 	# Replacing a tracked file with a submodule produces a checked out submodule
 	test_expect_success "$command: replace tracked file with submodule checks out submodule" '
@@ -699,6 +685,19 @@ test_submodule_recursing_with_args_common() {
 			test_submodule_content sub1 origin/replace_directory_with_sub1
 		)
 	'
+	# Switching to a commit with nested submodules recursively checks them out
+	test_expect_success "$command: nested submodules are checked out" '
+		prolog &&
+		reset_work_tree_to_interested no_submodule &&
+		(
+			cd submodule_update &&
+			git branch -t modify_sub1_recursively origin/modify_sub1_recursively &&
+			$command modify_sub1_recursively &&
+			test_superproject_content origin/modify_sub1_recursively &&
+			test_submodule_content sub1 origin/modify_sub1_recursively &&
+			test_submodule_content -C sub1 sub2 origin/modify_sub1_recursively
+		)
+	'
 
 	######################## Disappearing submodule #######################
 	# Removing a submodule removes its work tree ...
@@ -762,6 +761,21 @@ test_submodule_recursing_with_args_common() {
 		)
 	'
 
+	# Switching to a commit without nested submodules removes their worktrees
+	test_expect_success "$command: worktrees of nested submodules are removed" '
+		prolog &&
+		reset_work_tree_to_interested add_nested_sub &&
+		(
+			cd submodule_update &&
+			git branch -t no_submodule origin/no_submodule &&
+			$command no_submodule &&
+			test_superproject_content origin/no_submodule &&
+			! test_path_is_dir sub1 &&
+			test_must_fail git config -f .git/modules/sub1/config core.worktree &&
+			test_must_fail git config -f .git/modules/sub1/modules/sub2/config core.worktree
+		)
+	'
+
 	########################## Modified submodule #########################
 	# Updating a submodule sha1 updates the submodule's work tree
 	test_expect_success "$command: modified submodule updates submodule work tree" '
@@ -789,6 +803,23 @@ test_submodule_recursing_with_args_common() {
 			test_submodule_content sub1 origin/add_sub1
 		)
 	'
+	# Updating a submodule does not touch the currently checked out branch in the submodule
+	test_expect_success "$command: submodule branch is not changed, detach HEAD instead" '
+		prolog &&
+		reset_work_tree_to_interested add_sub1 &&
+		(
+			cd submodule_update &&
+			git -C sub1 checkout -b keep_branch &&
+			git -C sub1 rev-parse HEAD >expect &&
+			git branch -t modify_sub1 origin/modify_sub1 &&
+			$command modify_sub1 &&
+			test_superproject_content origin/modify_sub1 &&
+			test_submodule_content sub1 origin/modify_sub1 &&
+			git -C sub1 rev-parse keep_branch >actual &&
+			test_cmp expect actual &&
+			test_must_fail git -C sub1 symbolic-ref HEAD
+		)
+	'
 }
 
 # Declares and invokes several tests that, in various situations, checks that
@@ -908,7 +939,6 @@ test_submodule_switch_recursing_with_args () {
 		)
 	'
 
-	# recursing deeper than one level doesn't work yet.
 	test_expect_success "$command: modified submodule updates submodule recursively" '
 		prolog &&
 		reset_work_tree_to_interested add_nested_sub &&
diff --git a/t/t0018-advice.sh b/t/t0018-advice.sh
new file mode 100755
index 0000000000..e03554d2f3
--- /dev/null
+++ b/t/t0018-advice.sh
@@ -0,0 +1,32 @@
+#!/bin/sh
+
+test_description='Test advise_if_enabled functionality'
+
+. ./test-lib.sh
+
+test_expect_success 'advice should be printed when config variable is unset' '
+	cat >expect <<-\EOF &&
+	hint: This is a piece of advice
+	hint: Disable this message with "git config advice.nestedTag false"
+	EOF
+	test-tool advise "This is a piece of advice" 2>actual &&
+	test_i18ncmp expect actual
+'
+
+test_expect_success 'advice should be printed when config variable is set to true' '
+	cat >expect <<-\EOF &&
+	hint: This is a piece of advice
+	hint: Disable this message with "git config advice.nestedTag false"
+	EOF
+	test_config advice.nestedTag true &&
+	test-tool advise "This is a piece of advice" 2>actual &&
+	test_i18ncmp expect actual
+'
+
+test_expect_success 'advice should not be printed when config variable is set to false' '
+	test_config advice.nestedTag false &&
+	test-tool advise "This is a piece of advice" 2>actual &&
+	test_must_be_empty actual
+'
+
+test_done
diff --git a/t/t1450-fsck.sh b/t/t1450-fsck.sh
index d09eff503c..449ebc5657 100755
--- a/t/t1450-fsck.sh
+++ b/t/t1450-fsck.sh
@@ -133,6 +133,30 @@ test_expect_success 'other worktree HEAD link pointing at a funny place' '
 	test_i18ngrep "worktrees/other/HEAD points to something strange" out
 '
 
+test_expect_success 'commit with multiple signatures is okay' '
+	git cat-file commit HEAD >basis &&
+	cat >sigs <<-EOF &&
+	gpgsig -----BEGIN PGP SIGNATURE-----
+	  VGhpcyBpcyBub3QgcmVhbGx5IGEgc2lnbmF0dXJlLg==
+	  -----END PGP SIGNATURE-----
+	gpgsig-sha256 -----BEGIN PGP SIGNATURE-----
+	  VGhpcyBpcyBub3QgcmVhbGx5IGEgc2lnbmF0dXJlLg==
+	  -----END PGP SIGNATURE-----
+	EOF
+	sed -e "/^committer/q" basis >okay &&
+	cat sigs >>okay &&
+	echo >>okay &&
+	sed -e "1,/^$/d" basis >>okay &&
+	cat okay &&
+	new=$(git hash-object -t commit -w --stdin <okay) &&
+	test_when_finished "remove_object $new" &&
+	git update-ref refs/heads/bogus "$new" &&
+	test_when_finished "git update-ref -d refs/heads/bogus" &&
+	git fsck 2>out &&
+	cat out &&
+	! grep "commit $new" out
+'
+
 test_expect_success 'email without @ is okay' '
 	git cat-file commit HEAD >basis &&
 	sed "s/@/AT/" basis >okay &&
diff --git a/t/t3403-rebase-skip.sh b/t/t3403-rebase-skip.sh
index ee8a8dba52..a927774910 100755
--- a/t/t3403-rebase-skip.sh
+++ b/t/t3403-rebase-skip.sh
@@ -29,6 +29,13 @@ test_expect_success setup '
 	test_tick &&
 	git commit -m reverted-goodbye &&
 	git tag reverted-goodbye &&
+	git checkout goodbye &&
+	test_tick &&
+	GIT_AUTHOR_NAME="Another Author" \
+		GIT_AUTHOR_EMAIL="another.author@example.com" \
+		git commit --amend --no-edit -m amended-goodbye &&
+	test_tick &&
+	git tag amended-goodbye &&
 
 	git checkout -f skip-reference &&
 	echo moo > hello &&
@@ -85,6 +92,78 @@ test_expect_success 'moved back to branch correctly' '
 
 test_debug 'gitk --all & sleep 1'
 
+test_expect_success 'correct advice upon picking empty commit' '
+	test_when_finished "git rebase --abort" &&
+	test_must_fail git rebase -i --onto goodbye \
+		amended-goodbye^ amended-goodbye 2>err &&
+	test_i18ngrep "previous cherry-pick is now empty" err &&
+	test_i18ngrep "git rebase --skip" err &&
+	test_must_fail git commit &&
+	test_i18ngrep "git rebase --skip" err
+'
+
+test_expect_success 'correct authorship when committing empty pick' '
+	test_when_finished "git rebase --abort" &&
+	test_must_fail git rebase -i --onto goodbye \
+		amended-goodbye^ amended-goodbye &&
+	git commit --allow-empty &&
+	git log --pretty=format:"%an <%ae>%n%ad%B" -1 amended-goodbye >expect &&
+	git log --pretty=format:"%an <%ae>%n%ad%B" -1 HEAD >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'correct advice upon rewording empty commit' '
+	test_when_finished "git rebase --abort" &&
+	(
+		set_fake_editor &&
+		test_must_fail env FAKE_LINES="reword 1" git rebase -i \
+			--onto goodbye amended-goodbye^ amended-goodbye 2>err
+	) &&
+	test_i18ngrep "previous cherry-pick is now empty" err &&
+	test_i18ngrep "git rebase --skip" err &&
+	test_must_fail git commit &&
+	test_i18ngrep "git rebase --skip" err
+'
+
+test_expect_success 'correct advice upon editing empty commit' '
+	test_when_finished "git rebase --abort" &&
+	(
+		set_fake_editor &&
+		test_must_fail env FAKE_LINES="edit 1" git rebase -i \
+			--onto goodbye amended-goodbye^ amended-goodbye 2>err
+	) &&
+	test_i18ngrep "previous cherry-pick is now empty" err &&
+	test_i18ngrep "git rebase --skip" err &&
+	test_must_fail git commit &&
+	test_i18ngrep "git rebase --skip" err
+'
+
+test_expect_success 'correct advice upon cherry-picking an empty commit during a rebase' '
+	test_when_finished "git rebase --abort" &&
+	(
+		set_fake_editor &&
+		test_must_fail env FAKE_LINES="1 exec_git_cherry-pick_amended-goodbye" \
+			git rebase -i goodbye^ goodbye 2>err
+	) &&
+	test_i18ngrep "previous cherry-pick is now empty" err &&
+	test_i18ngrep "git cherry-pick --skip" err &&
+	test_must_fail git commit 2>err &&
+	test_i18ngrep "git cherry-pick --skip" err
+'
+
+test_expect_success 'correct advice upon multi cherry-pick picking an empty commit during a rebase' '
+	test_when_finished "git rebase --abort" &&
+	(
+		set_fake_editor &&
+		test_must_fail env FAKE_LINES="1 exec_git_cherry-pick_goodbye_amended-goodbye" \
+			git rebase -i goodbye^^ goodbye 2>err
+	) &&
+	test_i18ngrep "previous cherry-pick is now empty" err &&
+	test_i18ngrep "git cherry-pick --skip" err &&
+	test_must_fail git commit 2>err &&
+	test_i18ngrep "git cherry-pick --skip" err
+'
+
 test_expect_success 'fixup that empties commit fails' '
 	test_when_finished "git rebase --abort" &&
 	(
diff --git a/t/t3404-rebase-interactive.sh b/t/t3404-rebase-interactive.sh
index c5ce3ab760..4a7d21f898 100755
--- a/t/t3404-rebase-interactive.sh
+++ b/t/t3404-rebase-interactive.sh
@@ -187,7 +187,7 @@ test_expect_success 'no changes are a nop' '
 	git checkout branch2 &&
 	git rebase -i F &&
 	test "$(git symbolic-ref -q HEAD)" = "refs/heads/branch2" &&
-	test $(git rev-parse I) = $(git rev-parse HEAD)
+	test_cmp_rev I HEAD
 '
 
 test_expect_success 'test the [branch] option' '
@@ -196,16 +196,16 @@ test_expect_success 'test the [branch] option' '
 	git commit -m "stop here" &&
 	git rebase -i F branch2 &&
 	test "$(git symbolic-ref -q HEAD)" = "refs/heads/branch2" &&
-	test $(git rev-parse I) = $(git rev-parse branch2) &&
-	test $(git rev-parse I) = $(git rev-parse HEAD)
+	test_cmp_rev I branch2 &&
+	test_cmp_rev I HEAD
 '
 
 test_expect_success 'test --onto <branch>' '
 	git checkout -b test-onto branch2 &&
 	git rebase -i --onto branch1 F &&
 	test "$(git symbolic-ref -q HEAD)" = "refs/heads/test-onto" &&
-	test $(git rev-parse HEAD^) = $(git rev-parse branch1) &&
-	test $(git rev-parse I) = $(git rev-parse branch2)
+	test_cmp_rev HEAD^ branch1 &&
+	test_cmp_rev I branch2
 '
 
 test_expect_success 'rebase on top of a non-conflicting commit' '
@@ -214,12 +214,12 @@ test_expect_success 'rebase on top of a non-conflicting commit' '
 	git rebase -i branch2 &&
 	test file6 = $(git diff --name-only original-branch1) &&
 	test "$(git symbolic-ref -q HEAD)" = "refs/heads/branch1" &&
-	test $(git rev-parse I) = $(git rev-parse branch2) &&
-	test $(git rev-parse I) = $(git rev-parse HEAD~2)
+	test_cmp_rev I branch2 &&
+	test_cmp_rev I HEAD~2
 '
 
 test_expect_success 'reflog for the branch shows state before rebase' '
-	test $(git rev-parse branch1@{1}) = $(git rev-parse original-branch1)
+	test_cmp_rev branch1@{1} original-branch1
 '
 
 test_expect_success 'reflog for the branch shows correct finish message' '
@@ -279,7 +279,7 @@ test_expect_success 'show conflicted patch' '
 
 test_expect_success 'abort' '
 	git rebase --abort &&
-	test $(git rev-parse new-branch1) = $(git rev-parse HEAD) &&
+	test_cmp_rev new-branch1 HEAD &&
 	test "$(git symbolic-ref -q HEAD)" = "refs/heads/branch1" &&
 	test_path_is_missing .git/rebase-merge
 '
@@ -322,7 +322,7 @@ test_expect_success 'retain authorship w/ conflicts' '
 	echo resolved >conflict &&
 	git add conflict &&
 	git rebase --continue &&
-	test $(git rev-parse conflict-a^0) = $(git rev-parse HEAD^) &&
+	test_cmp_rev conflict-a^0 HEAD^ &&
 	git show >out &&
 	grep AttributeMe out
 '
@@ -339,7 +339,7 @@ test_expect_success 'squash' '
 			git rebase -i --onto master HEAD~2
 	) &&
 	test B = $(cat file7) &&
-	test $(git rev-parse HEAD^) = $(git rev-parse master)
+	test_cmp_rev HEAD^ master
 '
 
 test_expect_success 'retain authorship when squashing' '
@@ -398,9 +398,9 @@ test_expect_success REBASE_P 'preserve merges with -p' '
 	git update-index --refresh &&
 	git diff-files --quiet &&
 	git diff-index --quiet --cached HEAD -- &&
-	test $(git rev-parse HEAD~6) = $(git rev-parse branch1) &&
-	test $(git rev-parse HEAD~4^2) = $(git rev-parse to-be-preserved) &&
-	test $(git rev-parse HEAD^^2^) = $(git rev-parse HEAD^^^) &&
+	test_cmp_rev HEAD~6 branch1 &&
+	test_cmp_rev HEAD~4^2 to-be-preserved &&
+	test_cmp_rev HEAD^^2^ HEAD^^^ &&
 	test $(git show HEAD~5:file1) = B &&
 	test $(git show HEAD~3:file1) = C &&
 	test $(git show HEAD:file1) = E &&
@@ -432,7 +432,7 @@ test_expect_success '--continue tries to commit' '
 		git add file1 &&
 		FAKE_COMMIT_MESSAGE="chouette!" git rebase --continue
 	) &&
-	test $(git rev-parse HEAD^) = $(git rev-parse new-branch1) &&
+	test_cmp_rev HEAD^ new-branch1 &&
 	git show HEAD | grep chouette
 '
 
@@ -739,7 +739,7 @@ test_expect_success 'do "noop" when there is nothing to cherry-pick' '
 		--author="Somebody else <somebody@else.com>" &&
 	test $(git rev-parse branch3) != $(git rev-parse branch4) &&
 	git rebase -i branch3 &&
-	test $(git rev-parse branch3) = $(git rev-parse branch4)
+	test_cmp_rev branch3 branch4
 
 '
 
@@ -798,7 +798,7 @@ test_expect_success 'rebase -i continue with unstaged submodule' '
 	test_must_fail git rebase -i submodule-base &&
 	git reset &&
 	git rebase --continue &&
-	test $(git rev-parse submodule-base) = $(git rev-parse HEAD)
+	test_cmp_rev submodule-base HEAD
 '
 
 test_expect_success 'avoid unnecessary reset' '
@@ -821,7 +821,7 @@ test_expect_success 'reword' '
 			git rebase -i A &&
 		git show HEAD | grep "E changed" &&
 		test $(git rev-parse master) != $(git rev-parse HEAD) &&
-		test $(git rev-parse master^) = $(git rev-parse HEAD^) &&
+		test_cmp_rev master^ HEAD^ &&
 		FAKE_LINES="1 2 reword 3 4" FAKE_COMMIT_MESSAGE="D changed" \
 			git rebase -i A &&
 		git show HEAD^ | grep "D changed" &&
@@ -885,7 +885,7 @@ test_expect_success 'always cherry-pick with --no-ff' '
 		git diff HEAD~$p original-no-ff-branch~$p > out &&
 		test_must_be_empty out
 	done &&
-	test $(git rev-parse HEAD~3) = $(git rev-parse original-no-ff-branch~3) &&
+	test_cmp_rev HEAD~3 original-no-ff-branch~3 &&
 	git diff HEAD~3 original-no-ff-branch~3 > out &&
 	test_must_be_empty out
 '
@@ -1734,6 +1734,32 @@ test_expect_success 'post-commit hook is called' '
 	test_cmp expect actual
 '
 
+test_expect_success 'correct error message for partial commit after empty pick' '
+	test_when_finished "git rebase --abort" &&
+	(
+		set_fake_editor &&
+		FAKE_LINES="2 1 1" &&
+		export FAKE_LINES &&
+		test_must_fail git rebase -i A D
+	) &&
+	echo x >file1 &&
+	test_must_fail git commit file1 2>err &&
+	test_i18ngrep "cannot do a partial commit during a rebase." err
+'
+
+test_expect_success 'correct error message for commit --amend after empty pick' '
+	test_when_finished "git rebase --abort" &&
+	(
+		set_fake_editor &&
+		FAKE_LINES="1 1" &&
+		export FAKE_LINES &&
+		test_must_fail git rebase -i A D
+	) &&
+	echo x>file1 &&
+	test_must_fail git commit -a --amend 2>err &&
+	test_i18ngrep "middle of a rebase -- cannot amend." err
+'
+
 # This must be the last test in this file
 test_expect_success '$EDITOR and friends are unchanged' '
 	test_editor_unchanged
diff --git a/t/t3419-rebase-patch-id.sh b/t/t3419-rebase-patch-id.sh
index 94552669ae..d934583776 100755
--- a/t/t3419-rebase-patch-id.sh
+++ b/t/t3419-rebase-patch-id.sh
@@ -91,7 +91,7 @@ do_tests () {
 		git commit -q -m squashed &&
 		git checkout -q other^{} &&
 		test_must_fail git rebase squashed &&
-		rm -rf .git/rebase-apply
+		git rebase --quit
 	'
 }
 
diff --git a/t/t3424-rebase-empty.sh b/t/t3424-rebase-empty.sh
index 98fc2a558a..e1e30517ea 100755
--- a/t/t3424-rebase-empty.sh
+++ b/t/t3424-rebase-empty.sh
@@ -123,4 +123,12 @@ test_expect_success 'rebase --interactive uses default of --empty=ask' '
 	test_cmp expect actual
 '
 
+test_expect_success 'rebase --merge does not leave state laying around' '
+	git checkout -B testing localmods~2 &&
+	git rebase --merge upstream &&
+
+	test_path_is_missing .git/CHERRY_PICK_HEAD &&
+	test_path_is_missing .git/MERGE_MSG
+'
+
 test_done
diff --git a/t/t3507-cherry-pick-conflict.sh b/t/t3507-cherry-pick-conflict.sh
index 9bd482ce3b..752bc43487 100755
--- a/t/t3507-cherry-pick-conflict.sh
+++ b/t/t3507-cherry-pick-conflict.sh
@@ -161,6 +161,29 @@ test_expect_success 'successful commit clears CHERRY_PICK_HEAD' '
 
 	test_must_fail git rev-parse --verify CHERRY_PICK_HEAD
 '
+
+test_expect_success 'partial commit of cherry-pick fails' '
+	pristine_detach initial &&
+
+	test_must_fail git cherry-pick picked &&
+	echo resolved >foo &&
+	git add foo &&
+	test_must_fail git commit foo 2>err &&
+
+	test_i18ngrep "cannot do a partial commit during a cherry-pick." err
+'
+
+test_expect_success 'commit --amend of cherry-pick fails' '
+	pristine_detach initial &&
+
+	test_must_fail git cherry-pick picked &&
+	echo resolved >foo &&
+	git add foo &&
+	test_must_fail git commit --amend 2>err &&
+
+	test_i18ngrep "in the middle of a cherry-pick -- cannot amend." err
+'
+
 test_expect_success 'successful final commit clears cherry-pick state' '
 	pristine_detach initial &&
 
diff --git a/t/t3510-cherry-pick-sequence.sh b/t/t3510-cherry-pick-sequence.sh
index 793bcc7fe3..5b94fdaa67 100755
--- a/t/t3510-cherry-pick-sequence.sh
+++ b/t/t3510-cherry-pick-sequence.sh
@@ -123,7 +123,8 @@ test_expect_success 'revert --skip to skip commit' '
 test_expect_success 'skip "empty" commit' '
 	pristine_detach picked &&
 	test_commit dummy foo d &&
-	test_must_fail git cherry-pick anotherpick &&
+	test_must_fail git cherry-pick anotherpick 2>err &&
+	test_i18ngrep "git cherry-pick --skip" err &&
 	git cherry-pick --skip &&
 	test_cmp_rev dummy HEAD
 '
diff --git a/t/t4202-log.sh b/t/t4202-log.sh
index 0f766ba65f..5eeb739f3e 100755
--- a/t/t4202-log.sh
+++ b/t/t4202-log.sh
@@ -1627,6 +1627,66 @@ test_expect_success GPG 'log --graph --show-signature for merged tag in shallow
 	grep "tag signed_tag_shallow names a non-parent $hash" actual
 '
 
+test_expect_success GPG 'log --graph --show-signature for merged tag with missing key' '
+	test_when_finished "git reset --hard && git checkout master" &&
+	git checkout -b plain-nokey master &&
+	echo aaa >bar &&
+	git add bar &&
+	git commit -m bar_commit &&
+	git checkout -b tagged-nokey master &&
+	echo bbb >baz &&
+	git add baz &&
+	git commit -m baz_commit &&
+	git tag -s -m signed_tag_msg signed_tag_nokey &&
+	git checkout plain-nokey &&
+	git merge --no-ff -m msg signed_tag_nokey &&
+	GNUPGHOME=. git log --graph --show-signature -n1 plain-nokey >actual &&
+	grep "^|\\\  merged tag" actual &&
+	grep "^| | gpg: Signature made" actual &&
+	grep "^| | gpg: Can'"'"'t check signature: \(public key not found\|No public key\)" actual
+'
+
+test_expect_success GPG 'log --graph --show-signature for merged tag with bad signature' '
+	test_when_finished "git reset --hard && git checkout master" &&
+	git checkout -b plain-bad master &&
+	echo aaa >bar &&
+	git add bar &&
+	git commit -m bar_commit &&
+	git checkout -b tagged-bad master &&
+	echo bbb >baz &&
+	git add baz &&
+	git commit -m baz_commit &&
+	git tag -s -m signed_tag_msg signed_tag_bad &&
+	git cat-file tag signed_tag_bad >raw &&
+	sed -e "s/signed_tag_msg/forged/" raw >forged &&
+	git hash-object -w -t tag forged >forged.tag &&
+	git checkout plain-bad &&
+	git merge --no-ff -m msg "$(cat forged.tag)" &&
+	git log --graph --show-signature -n1 plain-bad >actual &&
+	grep "^|\\\  merged tag" actual &&
+	grep "^| | gpg: Signature made" actual &&
+	grep "^| | gpg: BAD signature from" actual
+'
+
+test_expect_success GPG 'log --show-signature for merged tag with GPG failure' '
+	test_when_finished "git reset --hard && git checkout master" &&
+	git checkout -b plain-fail master &&
+	echo aaa >bar &&
+	git add bar &&
+	git commit -m bar_commit &&
+	git checkout -b tagged-fail master &&
+	echo bbb >baz &&
+	git add baz &&
+	git commit -m baz_commit &&
+	git tag -s -m signed_tag_msg signed_tag_fail &&
+	git checkout plain-fail &&
+	git merge --no-ff -m msg signed_tag_fail &&
+	TMPDIR="$(pwd)/bogus" git log --show-signature -n1 plain-fail >actual &&
+	grep "^merged tag" actual &&
+	grep "^No signature" actual &&
+	! grep "^gpg: Signature made" actual
+'
+
 test_expect_success GPGSM 'log --graph --show-signature for merged tag x509' '
 	test_when_finished "git reset --hard && git checkout master" &&
 	test_config gpg.format x509 &&
@@ -1648,6 +1708,51 @@ test_expect_success GPGSM 'log --graph --show-signature for merged tag x509' '
 	grep "^| | gpgsm: Good signature" actual
 '
 
+test_expect_success GPGSM 'log --graph --show-signature for merged tag x509 missing key' '
+	test_when_finished "git reset --hard && git checkout master" &&
+	test_config gpg.format x509 &&
+	test_config user.signingkey $GIT_COMMITTER_EMAIL &&
+	git checkout -b plain-x509-nokey master &&
+	echo aaa >bar &&
+	git add bar &&
+	git commit -m bar_commit &&
+	git checkout -b tagged-x509-nokey master &&
+	echo bbb >baz &&
+	git add baz &&
+	git commit -m baz_commit &&
+	git tag -s -m signed_tag_msg signed_tag_x509_nokey &&
+	git checkout plain-x509-nokey &&
+	git merge --no-ff -m msg signed_tag_x509_nokey &&
+	GNUPGHOME=. git log --graph --show-signature -n1 plain-x509-nokey >actual &&
+	grep "^|\\\  merged tag" actual &&
+	grep "^| | gpgsm: certificate not found" actual
+'
+
+test_expect_success GPGSM 'log --graph --show-signature for merged tag x509 bad signature' '
+	test_when_finished "git reset --hard && git checkout master" &&
+	test_config gpg.format x509 &&
+	test_config user.signingkey $GIT_COMMITTER_EMAIL &&
+	git checkout -b plain-x509-bad master &&
+	echo aaa >bar &&
+	git add bar &&
+	git commit -m bar_commit &&
+	git checkout -b tagged-x509-bad master &&
+	echo bbb >baz &&
+	git add baz &&
+	git commit -m baz_commit &&
+	git tag -s -m signed_tag_msg signed_tag_x509_bad &&
+	git cat-file tag signed_tag_x509_bad >raw &&
+	sed -e "s/signed_tag_msg/forged/" raw >forged &&
+	git hash-object -w -t tag forged >forged.tag &&
+	git checkout plain-x509-bad &&
+	git merge --no-ff -m msg "$(cat forged.tag)" &&
+	git log --graph --show-signature -n1 plain-x509-bad >actual &&
+	grep "^|\\\  merged tag" actual &&
+	grep "^| | gpgsm: Signature made" actual &&
+	grep "^| | gpgsm: invalid signature" actual
+'
+
+
 test_expect_success GPG '--no-show-signature overrides --show-signature' '
 	git log -1 --show-signature --no-show-signature signed >actual &&
 	! grep "^gpg:" actual
diff --git a/t/t6022-merge-rename.sh b/t/t6022-merge-rename.sh
index d97cf48495..bbbba3dcbf 100755
--- a/t/t6022-merge-rename.sh
+++ b/t/t6022-merge-rename.sh
@@ -243,8 +243,7 @@ test_expect_success 'merge of identical changes in a renamed file' '
 	git reset --hard &&
 	git checkout change+rename &&
 
-	test-tool chmtime =31337 B &&
-	test-tool chmtime --get B >old-mtime &&
+	test-tool chmtime --get -3600 B >old-mtime &&
 	GIT_MERGE_VERBOSITY=3 git merge change >out &&
 
 	test-tool chmtime --get B >new-mtime &&
@@ -253,10 +252,12 @@ test_expect_success 'merge of identical changes in a renamed file' '
 	git reset --hard HEAD^ &&
 	git checkout change &&
 
-	test-tool chmtime =-1 M &&
-	test-tool chmtime --get M >old-mtime &&
+	# A will be renamed to B; we check mtimes and file presence
+	test_path_is_missing B &&
+	test-tool chmtime --get -3600 A >old-mtime &&
 	GIT_MERGE_VERBOSITY=3 git merge change+rename >out &&
 
+	test_path_is_missing A &&
 	test-tool chmtime --get B >new-mtime &&
 	test $(cat old-mtime) -lt $(cat new-mtime)
 '
@@ -645,7 +646,7 @@ test_expect_success 'setup avoid unnecessary update, normal rename' '
 
 test_expect_success 'avoid unnecessary update, normal rename' '
 	git checkout -q avoid-unnecessary-update-1^0 &&
-	test-tool chmtime --get =1000000000 rename >expect &&
+	test-tool chmtime --get -3600 rename >expect &&
 	git merge merge-branch-1 &&
 	test-tool chmtime --get rename >actual &&
 	test_cmp expect actual # "rename" should have stayed intact
@@ -677,7 +678,7 @@ test_expect_success 'setup to test avoiding unnecessary update, with D/F conflic
 
 test_expect_success 'avoid unnecessary update, with D/F conflict' '
 	git checkout -q avoid-unnecessary-update-2^0 &&
-	test-tool chmtime --get =1000000000 df >expect &&
+	test-tool chmtime --get -3600 df >expect &&
 	git merge merge-branch-2 &&
 	test-tool chmtime --get df >actual &&
 	test_cmp expect actual # "df" should have stayed intact
@@ -708,7 +709,7 @@ test_expect_success 'setup avoid unnecessary update, dir->(file,nothing)' '
 
 test_expect_success 'avoid unnecessary update, dir->(file,nothing)' '
 	git checkout -q master^0 &&
-	test-tool chmtime --get =1000000000 df >expect &&
+	test-tool chmtime --get -3600 df >expect &&
 	git merge side &&
 	test-tool chmtime --get df >actual &&
 	test_cmp expect actual # "df" should have stayed intact
@@ -737,7 +738,7 @@ test_expect_success 'setup avoid unnecessary update, modify/delete' '
 
 test_expect_success 'avoid unnecessary update, modify/delete' '
 	git checkout -q master^0 &&
-	test-tool chmtime --get =1000000000 file >expect &&
+	test-tool chmtime --get -3600 file >expect &&
 	test_must_fail git merge side &&
 	test-tool chmtime --get file >actual &&
 	test_cmp expect actual # "file" should have stayed intact
@@ -765,7 +766,7 @@ test_expect_success 'setup avoid unnecessary update, rename/add-dest' '
 
 test_expect_success 'avoid unnecessary update, rename/add-dest' '
 	git checkout -q master^0 &&
-	test-tool chmtime --get =1000000000 newfile >expect &&
+	test-tool chmtime --get -3600 newfile >expect &&
 	git merge side &&
 	test-tool chmtime --get newfile >actual &&
 	test_cmp expect actual # "file" should have stayed intact
diff --git a/t/t6046-merge-skip-unneeded-updates.sh b/t/t6046-merge-skip-unneeded-updates.sh
index 962030ecdb..1ddc9e6626 100755
--- a/t/t6046-merge-skip-unneeded-updates.sh
+++ b/t/t6046-merge-skip-unneeded-updates.sh
@@ -71,8 +71,7 @@ test_expect_success '1a-L: Modify(A)/Modify(B), change on B subset of A' '
 
 		git checkout A^0 &&
 
-		test-tool chmtime =-1 b &&
-		test-tool chmtime --get b >old-mtime &&
+		test-tool chmtime --get -3600 b >old-mtime &&
 
 		GIT_MERGE_VERBOSITY=3 git merge -s recursive B^0 >out 2>err &&
 
@@ -102,8 +101,7 @@ test_expect_success '1a-R: Modify(A)/Modify(B), change on B subset of A' '
 
 		git checkout B^0 &&
 
-		test-tool chmtime =-1 b &&
-		test-tool chmtime --get b >old-mtime &&
+		test-tool chmtime --get -3600 b >old-mtime &&
 		GIT_MERGE_VERBOSITY=3 git merge -s recursive A^0 >out 2>err &&
 
 		# Make sure b WAS updated
@@ -198,8 +196,7 @@ test_expect_success '2a-R: Modify/rename, merge into rename side' '
 
 		git checkout B^0 &&
 
-		test-tool chmtime =-1 c &&
-		test-tool chmtime --get c >old-mtime &&
+		test-tool chmtime --get -3600 c >old-mtime &&
 		GIT_MERGE_VERBOSITY=3 git merge -s recursive A^0 >out 2>err &&
 
 		# Make sure c WAS updated
@@ -266,8 +263,7 @@ test_expect_success '2b-L: Rename+Mod(A)/Mod(B), B mods subset of A' '
 
 		git checkout A^0 &&
 
-		test-tool chmtime =-1 c &&
-		test-tool chmtime --get c >old-mtime &&
+		test-tool chmtime --get -3600 c >old-mtime &&
 		GIT_MERGE_VERBOSITY=3 git merge -s recursive B^0 >out 2>err &&
 
 		test_must_be_empty err &&
@@ -373,8 +369,7 @@ test_expect_success '2c: Modify b & add c VS rename b->c' '
 
 		git checkout A^0 &&
 
-		test-tool chmtime =-1 c &&
-		test-tool chmtime --get c >old-mtime &&
+		test-tool chmtime --get -3600 c >old-mtime &&
 		GIT_MERGE_VERBOSITY=3 &&
 		export GIT_MERGE_VERBOSITY &&
 		test_must_fail git merge -s recursive B^0 >out 2>err &&
@@ -679,8 +674,7 @@ test_expect_failure '4a: Change on A, change on B subset of A, dirty mods presen
 		git checkout A^0 &&
 		echo "File rewritten" >b &&
 
-		test-tool chmtime =-1 b &&
-		test-tool chmtime --get b >old-mtime &&
+		test-tool chmtime --get -3600 b >old-mtime &&
 
 		GIT_MERGE_VERBOSITY=3 git merge -s recursive B^0 >out 2>err &&
 
@@ -747,8 +741,7 @@ test_expect_success '4b: Rename+Mod(A)/Mod(B), change on B subset of A, dirty mo
 		git checkout A^0 &&
 		echo "File rewritten" >c &&
 
-		test-tool chmtime =-1 c &&
-		test-tool chmtime --get c >old-mtime &&
+		test-tool chmtime --get -3600 c >old-mtime &&
 
 		GIT_MERGE_VERBOSITY=3 git merge -s recursive B^0 >out 2>err &&
 
diff --git a/t/t6136-pathspec-in-bare.sh b/t/t6136-pathspec-in-bare.sh
new file mode 100755
index 0000000000..b117251366
--- /dev/null
+++ b/t/t6136-pathspec-in-bare.sh
@@ -0,0 +1,38 @@
+#!/bin/sh
+
+test_description='diagnosing out-of-scope pathspec'
+
+. ./test-lib.sh
+
+test_expect_success 'setup a bare and non-bare repository' '
+	test_commit file1 &&
+	git clone --bare . bare
+'
+
+test_expect_success 'log and ls-files in a bare repository' '
+	(
+		cd bare &&
+		test_must_fail git log -- .. >out 2>err &&
+		test_must_be_empty out &&
+		test_i18ngrep "outside repository" err &&
+
+		test_must_fail git ls-files -- .. >out 2>err &&
+		test_must_be_empty out &&
+		test_i18ngrep "outside repository" err
+	)
+'
+
+test_expect_success 'log and ls-files in .git directory' '
+	(
+		cd .git &&
+		test_must_fail git log -- .. >out 2>err &&
+		test_must_be_empty out &&
+		test_i18ngrep "outside repository" err &&
+
+		test_must_fail git ls-files -- .. >out 2>err &&
+		test_must_be_empty out &&
+		test_i18ngrep "outside repository" err
+	)
+'
+
+test_done
diff --git a/t/t6200-fmt-merge-msg.sh b/t/t6200-fmt-merge-msg.sh
index 8a72b4c43a..b15582a7a2 100755
--- a/t/t6200-fmt-merge-msg.sh
+++ b/t/t6200-fmt-merge-msg.sh
@@ -6,6 +6,7 @@
 test_description='fmt-merge-msg test'
 
 . ./test-lib.sh
+. "$TEST_DIRECTORY/lib-gpg.sh"
 
 test_expect_success setup '
 	echo one >one &&
@@ -73,6 +74,10 @@ test_expect_success setup '
 	apos="'\''"
 '
 
+test_expect_success GPG 'set up a signed tag' '
+	git tag -s -m signed-tag-msg signed-good-tag left
+'
+
 test_expect_success 'message for merging local branch' '
 	echo "Merge branch ${apos}left${apos}" >expected &&
 
@@ -83,6 +88,24 @@ test_expect_success 'message for merging local branch' '
 	test_cmp expected actual
 '
 
+test_expect_success GPG 'message for merging local tag signed by good key' '
+	git checkout master &&
+	git fetch . signed-good-tag &&
+	git fmt-merge-msg <.git/FETCH_HEAD >actual 2>&1 &&
+	grep "^Merge tag ${apos}signed-good-tag${apos}" actual &&
+	grep "^# gpg: Signature made" actual &&
+	grep "^# gpg: Good signature from" actual
+'
+
+test_expect_success GPG 'message for merging local tag signed by unknown key' '
+	git checkout master &&
+	git fetch . signed-good-tag &&
+	GNUPGHOME=. git fmt-merge-msg <.git/FETCH_HEAD >actual 2>&1 &&
+	grep "^Merge tag ${apos}signed-good-tag${apos}" actual &&
+	grep "^# gpg: Signature made" actual &&
+	grep "^# gpg: Can${apos}t check signature: \(public key not found\|No public key\)" actual
+'
+
 test_expect_success 'message for merging external branch' '
 	echo "Merge branch ${apos}left${apos} of $(pwd)" >expected &&
 
diff --git a/t/t6300-for-each-ref.sh b/t/t6300-for-each-ref.sh
index 9c910ce746..b3c1092338 100755
--- a/t/t6300-for-each-ref.sh
+++ b/t/t6300-for-each-ref.sh
@@ -20,6 +20,10 @@ setdate_and_increment () {
 }
 
 test_expect_success setup '
+	test_oid_cache <<-EOF &&
+	disklen sha1:138
+	disklen sha256:154
+	EOF
 	setdate_and_increment &&
 	echo "Using $datestamp" > one &&
 	git add one &&
@@ -50,6 +54,9 @@ test_atom() {
 	"
 }
 
+hexlen=$(test_oid hexsz)
+disklen=$(test_oid disklen)
+
 test_atom head refname refs/heads/master
 test_atom head refname: refs/heads/master
 test_atom head refname:short master
@@ -82,9 +89,9 @@ test_atom head push:rstrip=-1 refs
 test_atom head push:strip=1 remotes/myfork/master
 test_atom head push:strip=-1 master
 test_atom head objecttype commit
-test_atom head objectsize 171
-test_atom head objectsize:disk 138
-test_atom head deltabase 0000000000000000000000000000000000000000
+test_atom head objectsize $((131 + hexlen))
+test_atom head objectsize:disk $disklen
+test_atom head deltabase $ZERO_OID
 test_atom head objectname $(git rev-parse refs/heads/master)
 test_atom head objectname:short $(git rev-parse --short refs/heads/master)
 test_atom head objectname:short=1 $(git rev-parse --short=1 refs/heads/master)
@@ -125,11 +132,11 @@ test_atom tag refname:short testtag
 test_atom tag upstream ''
 test_atom tag push ''
 test_atom tag objecttype tag
-test_atom tag objectsize 154
-test_atom tag objectsize:disk 138
-test_atom tag '*objectsize:disk' 138
-test_atom tag deltabase 0000000000000000000000000000000000000000
-test_atom tag '*deltabase' 0000000000000000000000000000000000000000
+test_atom tag objectsize $((114 + hexlen))
+test_atom tag objectsize:disk $disklen
+test_atom tag '*objectsize:disk' $disklen
+test_atom tag deltabase $ZERO_OID
+test_atom tag '*deltabase' $ZERO_OID
 test_atom tag objectname $(git rev-parse refs/tags/testtag)
 test_atom tag objectname:short $(git rev-parse --short refs/tags/testtag)
 test_atom head objectname:short=1 $(git rev-parse --short=1 refs/heads/master)
@@ -139,7 +146,7 @@ test_atom tag parent ''
 test_atom tag numparent ''
 test_atom tag object $(git rev-parse refs/tags/testtag^0)
 test_atom tag type 'commit'
-test_atom tag '*objectname' 'ea122842f48be4afb2d1fc6a4b96c05885ab7463'
+test_atom tag '*objectname' $(git rev-parse refs/tags/testtag^{})
 test_atom tag '*objecttype' 'commit'
 test_atom tag author ''
 test_atom tag authorname ''
@@ -643,7 +650,7 @@ test_atom refs/tags/signed-long contents "subject line
 body contents
 $sig"
 
-cat >expected <<EOF
+sort >expected <<EOF
 $(git rev-parse refs/tags/bogo) <committer@example.com> refs/tags/bogo
 $(git rev-parse refs/tags/master) <committer@example.com> refs/tags/master
 EOF
diff --git a/t/t7004-tag.sh b/t/t7004-tag.sh
index 6db92bd3ba..74b637deb2 100755
--- a/t/t7004-tag.sh
+++ b/t/t7004-tag.sh
@@ -1726,6 +1726,7 @@ test_expect_success 'recursive tagging should give advice' '
 	hint: already a tag. If you meant to tag the object that it points to, use:
 	hint: |
 	hint: 	git tag -f nested annotated-v4.0^{}
+	hint: Disable this message with "git config advice.nestedTag false"
 	EOF
 	git tag -m nested nested annotated-v4.0 2>actual &&
 	test_i18ncmp expect actual
diff --git a/t/t7112-reset-submodule.sh b/t/t7112-reset-submodule.sh
index a1cb9ff858..67346424a5 100755
--- a/t/t7112-reset-submodule.sh
+++ b/t/t7112-reset-submodule.sh
@@ -5,7 +5,6 @@ test_description='reset can handle submodules'
 . ./test-lib.sh
 . "$TEST_DIRECTORY"/lib-submodule-update.sh
 
-KNOWN_FAILURE_SUBMODULE_RECURSIVE_NESTED=1
 KNOWN_FAILURE_DIRECTORY_SUBMODULE_CONFLICTS=1
 KNOWN_FAILURE_SUBMODULE_OVERWRITE_IGNORED_UNTRACKED=1
 
diff --git a/t/t7510-signed-commit.sh b/t/t7510-signed-commit.sh
index 0c06d22a00..6baaa1ad91 100755
--- a/t/t7510-signed-commit.sh
+++ b/t/t7510-signed-commit.sh
@@ -6,6 +6,11 @@ GNUPGHOME_NOT_USED=$GNUPGHOME
 . "$TEST_DIRECTORY/lib-gpg.sh"
 
 test_expect_success GPG 'create signed commits' '
+	test_oid_cache <<-\EOF &&
+	header sha1:gpgsig
+	header sha256:gpgsig-sha256
+	EOF
+
 	test_when_finished "test_unconfig commit.gpgsign" &&
 
 	echo 1 >file && git add file &&
@@ -155,6 +160,11 @@ test_expect_success GPG 'verify signatures with --raw' '
 	)
 '
 
+test_expect_success GPG 'proper header is used for hash algorithm' '
+	git cat-file commit fourth-signed >output &&
+	grep "^$(test_oid header) -----BEGIN PGP SIGNATURE-----" output
+'
+
 test_expect_success GPG 'show signed commit with signature' '
 	git show -s initial >commit &&
 	git show -s --show-signature initial >show &&
@@ -162,7 +172,7 @@ test_expect_success GPG 'show signed commit with signature' '
 	git cat-file commit initial >cat &&
 	grep -v -e "gpg: " -e "Warning: " show >show.commit &&
 	grep -e "gpg: " -e "Warning: " show >show.gpg &&
-	grep -v "^ " cat | grep -v "^gpgsig " >cat.commit &&
+	grep -v "^ " cat | grep -v "^$(test_oid header) " >cat.commit &&
 	test_cmp show.commit commit &&
 	test_cmp show.gpg verify.2 &&
 	test_cmp cat.commit verify.1
@@ -299,10 +309,10 @@ test_expect_success GPG 'check config gpg.format values' '
 test_expect_success GPG 'detect fudged commit with double signature' '
 	sed -e "/gpgsig/,/END PGP/d" forged1 >double-base &&
 	sed -n -e "/gpgsig/,/END PGP/p" forged1 | \
-		sed -e "s/^gpgsig//;s/^ //" | gpg --dearmor >double-sig1.sig &&
+		sed -e "s/^$(test_oid header)//;s/^ //" | gpg --dearmor >double-sig1.sig &&
 	gpg -o double-sig2.sig -u 29472784 --detach-sign double-base &&
 	cat double-sig1.sig double-sig2.sig | gpg --enarmor >double-combined.asc &&
-	sed -e "s/^\(-.*\)ARMORED FILE/\1SIGNATURE/;1s/^/gpgsig /;2,\$s/^/ /" \
+	sed -e "s/^\(-.*\)ARMORED FILE/\1SIGNATURE/;1s/^/$(test_oid header) /;2,\$s/^/ /" \
 		double-combined.asc > double-gpgsig &&
 	sed -e "/committer/r double-gpgsig" double-base >double-commit &&
 	git hash-object -w -t commit double-commit >double-commit.commit &&
diff --git a/t/t9300-fast-import.sh b/t/t9300-fast-import.sh
index 3e41c58a13..768257b29e 100755
--- a/t/t9300-fast-import.sh
+++ b/t/t9300-fast-import.sh
@@ -3381,4 +3381,113 @@ test_expect_success 'X: handling encoding' '
 	git log -1 --format=%B encoding | grep $(printf "\317\200")
 '
 
+###
+### series Y (submodules and hash algorithms)
+###
+
+cat >Y-sub-input <<\Y_INPUT_END
+blob
+mark :1
+data 4
+foo
+
+reset refs/heads/master
+commit refs/heads/master
+mark :2
+author Full Name <user@company.tld> 1000000000 +0100
+committer Full Name <user@company.tld> 1000000000 +0100
+data 24
+Test submodule commit 1
+M 100644 :1 file
+
+blob
+mark :3
+data 8
+foo
+bar
+
+commit refs/heads/master
+mark :4
+author Full Name <user@company.tld> 1000000001 +0100
+committer Full Name <user@company.tld> 1000000001 +0100
+data 24
+Test submodule commit 2
+from :2
+M 100644 :3 file
+Y_INPUT_END
+
+# Note that the submodule object IDs are intentionally not translated.
+cat >Y-main-input <<\Y_INPUT_END
+blob
+mark :1
+data 4
+foo
+
+reset refs/heads/master
+commit refs/heads/master
+mark :2
+author Full Name <user@company.tld> 2000000000 +0100
+committer Full Name <user@company.tld> 2000000000 +0100
+data 14
+Test commit 1
+M 100644 :1 file
+
+blob
+mark :3
+data 73
+[submodule "sub1"]
+	path = sub1
+	url = https://void.example.com/main.git
+
+commit refs/heads/master
+mark :4
+author Full Name <user@company.tld> 2000000001 +0100
+committer Full Name <user@company.tld> 2000000001 +0100
+data 14
+Test commit 2
+from :2
+M 100644 :3 .gitmodules
+M 160000 0712c5be7cf681388e355ef47525aaf23aee1a6d sub1
+
+blob
+mark :5
+data 8
+foo
+bar
+
+commit refs/heads/master
+mark :6
+author Full Name <user@company.tld> 2000000002 +0100
+committer Full Name <user@company.tld> 2000000002 +0100
+data 14
+Test commit 3
+from :4
+M 100644 :5 file
+M 160000 ff729f5e62f72c0c3978207d9a80e5f3a65f14d7 sub1
+Y_INPUT_END
+
+cat >Y-marks <<\Y_INPUT_END
+:2 0712c5be7cf681388e355ef47525aaf23aee1a6d
+:4 ff729f5e62f72c0c3978207d9a80e5f3a65f14d7
+Y_INPUT_END
+
+test_expect_success 'Y: setup' '
+	test_oid_cache <<-EOF
+	Ymaster sha1:9afed2f9161ddf416c0a1863b8b0725b00070504
+	Ymaster sha256:c0a1010da1df187b2e287654793df01b464bd6f8e3f17fc1481a7dadf84caee3
+	EOF
+'
+
+test_expect_success 'Y: rewrite submodules' '
+	git init main1 &&
+	(
+		cd main1 &&
+		git init sub2 &&
+		git -C sub2 fast-import --export-marks=../sub2-marks <../Y-sub-input &&
+		git fast-import --rewrite-submodules-from=sub:../Y-marks \
+			--rewrite-submodules-to=sub:sub2-marks <../Y-main-input &&
+		test "$(git rev-parse master)" = "$(test_oid Ymaster)"
+	)
+'
+
 test_done
diff --git a/t/test-lib.sh b/t/test-lib.sh
index 0ea1e5a05e..9fe390bd5a 100644
--- a/t/test-lib.sh
+++ b/t/test-lib.sh
@@ -494,21 +494,6 @@ case $(echo $GIT_TRACE |tr "[A-Z]" "[a-z]") in
 	;;
 esac
 
-# Convenience
-#
-# A regexp to match 5, 35 and 40 hexdigits
-_x05='[0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f]'
-_x35="$_x05$_x05$_x05$_x05$_x05$_x05$_x05"
-_x40="$_x35$_x05"
-
-# Zero SHA-1
-_z40=0000000000000000000000000000000000000000
-
-OID_REGEX="$_x40"
-ZERO_OID=$_z40
-EMPTY_TREE=4b825dc642cb6eb9a060e54bf8d69288fbee4904
-EMPTY_BLOB=e69de29bb2d1d6434b8b29ae775ad8c2e48c5391
-
 # Line feed
 LF='
 '
@@ -1383,6 +1368,20 @@ then
 	fi
 fi
 
+# Convenience
+# A regexp to match 5, 35 and 40 hexdigits
+_x05='[0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f]'
+_x35="$_x05$_x05$_x05$_x05$_x05$_x05$_x05"
+_x40="$_x35$_x05"
+
+test_oid_init
+
+ZERO_OID=$(test_oid zero)
+OID_REGEX=$(echo $ZERO_OID | sed -e 's/0/[0-9a-f]/g')
+EMPTY_TREE=$(test_oid empty_tree)
+EMPTY_BLOB=$(test_oid empty_blob)
+_z40=$ZERO_OID
+
 # Provide an implementation of the 'yes' utility; the upper bound
 # limit is there to help Windows that cannot stop this loop from
 # wasting cycles when the downstream stops reading, so do not be