Merge branch 'pb/subtree-split-and-merge-after-squashing-tag-fix'

A bugfix to "git subtree" in its split and merge features.

* pb/subtree-split-and-merge-after-squashing-tag-fix:
  subtree: fix split after annotated tag was squashed merged
  subtree: fix squash merging after annotated tag was squashed merged
  subtree: process 'git-subtree-split' trailer in separate function
  subtree: use named variables instead of "$@" in cmd_pull
  subtree: define a variable before its first use in 'find_latest_squash'
  subtree: prefix die messages with 'fatal'
  subtree: add 'die_incompatible_opt' function to reduce duplication
  subtree: use 'git rev-parse --verify [--quiet]' for better error messages
  test-lib-functions: mark 'test_commit' variables as 'local'

4 files changed, 192 insertions, 77 deletions

diff --git a/contrib/subtree/git-subtree.sh b/contrib/subtree/git-subtree.sh
index 7562a395c24..10c9c87839a 100755
--- a/contrib/subtree/git-subtree.sh
+++ b/contrib/subtree/git-subtree.sh
@@ -98,10 +98,18 @@ progress () {
 assert () {
 	if ! "$@"
 	then
-		die "assertion failed: $*"
+		die "fatal: assertion failed: $*"
 	fi
 }
 
+# Usage: die_incompatible_opt OPTION COMMAND
+die_incompatible_opt () {
+	assert test "$#" = 2
+	opt="$1"
+	arg_command="$2"
+	die "fatal: the '$opt' flag does not make sense with 'git subtree $arg_command'."
+}
+
 main () {
 	if test $# -eq 0
 	then
@@ -147,7 +155,7 @@ main () {
 		allow_addmerge=$arg_split_rejoin
 		;;
 	*)
-		die "Unknown command '$arg_command'"
+		die "fatal: unknown command '$arg_command'"
 		;;
 	esac
 	# Reset the arguments array for "real" flag parsing.
@@ -176,16 +184,16 @@ main () {
 			arg_debug=1
 			;;
 		--annotate)
-			test -n "$allow_split" || die "The '$opt' flag does not make sense with 'git subtree $arg_command'."
+			test -n "$allow_split" || die_incompatible_opt "$opt" "$arg_command"
 			arg_split_annotate="$1"
 			shift
 			;;
 		--no-annotate)
-			test -n "$allow_split" || die "The '$opt' flag does not make sense with 'git subtree $arg_command'."
+			test -n "$allow_split" || die_incompatible_opt "$opt" "$arg_command"
 			arg_split_annotate=
 			;;
 		-b)
-			test -n "$allow_split" || die "The '$opt' flag does not make sense with 'git subtree $arg_command'."
+			test -n "$allow_split" || die_incompatible_opt "$opt" "$arg_command"
 			arg_split_branch="$1"
 			shift
 			;;
@@ -194,7 +202,7 @@ main () {
 			shift
 			;;
 		-m)
-			test -n "$allow_addmerge" || die "The '$opt' flag does not make sense with 'git subtree $arg_command'."
+			test -n "$allow_addmerge" || die_incompatible_opt "$opt" "$arg_command"
 			arg_addmerge_message="$1"
 			shift
 			;;
@@ -202,41 +210,41 @@ main () {
 			arg_prefix=
 			;;
 		--onto)
-			test -n "$allow_split" || die "The '$opt' flag does not make sense with 'git subtree $arg_command'."
+			test -n "$allow_split" || die_incompatible_opt "$opt" "$arg_command"
 			arg_split_onto="$1"
 			shift
 			;;
 		--no-onto)
-			test -n "$allow_split" || die "The '$opt' flag does not make sense with 'git subtree $arg_command'."
+			test -n "$allow_split" || die_incompatible_opt "$opt" "$arg_command"
 			arg_split_onto=
 			;;
 		--rejoin)
-			test -n "$allow_split" || die "The '$opt' flag does not make sense with 'git subtree $arg_command'."
+			test -n "$allow_split" || die_incompatible_opt "$opt" "$arg_command"
 			;;
 		--no-rejoin)
-			test -n "$allow_split" || die "The '$opt' flag does not make sense with 'git subtree $arg_command'."
+			test -n "$allow_split" || die_incompatible_opt "$opt" "$arg_command"
 			;;
 		--ignore-joins)
-			test -n "$allow_split" || die "The '$opt' flag does not make sense with 'git subtree $arg_command'."
+			test -n "$allow_split" || die_incompatible_opt "$opt" "$arg_command"
 			arg_split_ignore_joins=1
 			;;
 		--no-ignore-joins)
-			test -n "$allow_split" || die "The '$opt' flag does not make sense with 'git subtree $arg_command'."
+			test -n "$allow_split" || die_incompatible_opt "$opt" "$arg_command"
 			arg_split_ignore_joins=
 			;;
 		--squash)
-			test -n "$allow_addmerge" || die "The '$opt' flag does not make sense with 'git subtree $arg_command'."
+			test -n "$allow_addmerge" || die_incompatible_opt "$opt" "$arg_command"
 			arg_addmerge_squash=1
 			;;
 		--no-squash)
-			test -n "$allow_addmerge" || die "The '$opt' flag does not make sense with 'git subtree $arg_command'."
+			test -n "$allow_addmerge" || die_incompatible_opt "$opt" "$arg_command"
 			arg_addmerge_squash=
 			;;
 		--)
 			break
 			;;
 		*)
-			die "Unexpected option: $opt"
+			die "fatal: unexpected option: $opt"
 			;;
 		esac
 	done
@@ -244,17 +252,17 @@ main () {
 
 	if test -z "$arg_prefix"
 	then
-		die "You must provide the --prefix option."
+		die "fatal: you must provide the --prefix option."
 	fi
 
 	case "$arg_command" in
 	add)
 		test -e "$arg_prefix" &&
-			die "prefix '$arg_prefix' already exists."
+			die "fatal: prefix '$arg_prefix' already exists."
 		;;
 	*)
 		test -e "$arg_prefix" ||
-			die "'$arg_prefix' does not exist; use 'git subtree add'"
+			die "fatal: '$arg_prefix' does not exist; use 'git subtree add'"
 		;;
 	esac
 
@@ -274,11 +282,11 @@ cache_setup () {
 	assert test $# = 0
 	cachedir="$GIT_DIR/subtree-cache/$$"
 	rm -rf "$cachedir" ||
-		die "Can't delete old cachedir: $cachedir"
+		die "fatal: can't delete old cachedir: $cachedir"
 	mkdir -p "$cachedir" ||
-		die "Can't create new cachedir: $cachedir"
+		die "fatal: can't create new cachedir: $cachedir"
 	mkdir -p "$cachedir/notree" ||
-		die "Can't create new cachedir: $cachedir/notree"
+		die "fatal: can't create new cachedir: $cachedir/notree"
 	debug "Using cachedir: $cachedir" >&2
 }
 
@@ -334,7 +342,7 @@ cache_set () {
 		test "$oldrev" != "latest_new" &&
 		test -e "$cachedir/$oldrev"
 	then
-		die "cache for $oldrev already exists!"
+		die "fatal: cache for $oldrev already exists!"
 	fi
 	echo "$newrev" >"$cachedir/$oldrev"
 }
@@ -363,13 +371,47 @@ try_remove_previous () {
 	fi
 }
 
-# Usage: find_latest_squash DIR
+# Usage: process_subtree_split_trailer SPLIT_HASH MAIN_HASH [REPOSITORY]
+process_subtree_split_trailer () {
+	assert test $# = 2 -o $# = 3
+	b="$1"
+	sq="$2"
+	repository=""
+	if test "$#" = 3
+	then
+		repository="$3"
+	fi
+	fail_msg="fatal: could not rev-parse split hash $b from commit $sq"
+	if ! sub="$(git rev-parse --verify --quiet "$b^{commit}")"
+	then
+		# if 'repository' was given, try to fetch the 'git-subtree-split' hash
+		# before 'rev-parse'-ing it again, as it might be a tag that we do not have locally
+		if test -n "${repository}"
+		then
+			git fetch "$repository" "$b"
+			sub="$(git rev-parse --verify --quiet "$b^{commit}")" ||
+				die "$fail_msg"
+		else
+			hint1=$(printf "hint: hash might be a tag, try fetching it from the subtree repository:")
+			hint2=$(printf "hint:    git fetch <subtree-repository> $b")
+			fail_msg=$(printf "$fail_msg\n$hint1\n$hint2")
+			die "$fail_msg"
+		fi
+	fi
+}
+
+# Usage: find_latest_squash DIR [REPOSITORY]
 find_latest_squash () {
-	assert test $# = 1
-	debug "Looking for latest squash ($dir)..."
+	assert test $# = 1 -o $# = 2
+	dir="$1"
+	repository=""
+	if test "$#" = 2
+	then
+		repository="$2"
+	fi
+	debug "Looking for latest squash (dir=$dir, repository=$repository)..."
 	local indent=$(($indent + 1))
 
-	dir="$1"
 	sq=
 	main=
 	sub=
@@ -387,8 +429,7 @@ find_latest_squash () {
 			main="$b"
 			;;
 		git-subtree-split:)
-			sub="$(git rev-parse "$b^{commit}")" ||
-			die "could not rev-parse split hash $b from commit $sq"
+			process_subtree_split_trailer "$b" "$sq" "$repository"
 			;;
 		END)
 			if test -n "$sub"
@@ -412,14 +453,19 @@ find_latest_squash () {
 	done || exit $?
 }
 
-# Usage: find_existing_splits DIR REV
+# Usage: find_existing_splits DIR REV [REPOSITORY]
 find_existing_splits () {
-	assert test $# = 2
+	assert test $# = 2 -o $# = 3
 	debug "Looking for prior splits..."
 	local indent=$(($indent + 1))
 
 	dir="$1"
 	rev="$2"
+	repository=""
+	if test "$#" = 3
+	then
+		repository="$3"
+	fi
 	main=
 	sub=
 	local grep_format="^git-subtree-dir: $dir/*\$"
@@ -439,8 +485,7 @@ find_existing_splits () {
 			main="$b"
 			;;
 		git-subtree-split:)
-			sub="$(git rev-parse "$b^{commit}")" ||
-			die "could not rev-parse split hash $b from commit $sq"
+			process_subtree_split_trailer "$b" "$sq" "$repository"
 			;;
 		END)
 			debug "Main is: '$main'"
@@ -490,7 +535,7 @@ copy_commit () {
 			cat
 		) |
 		git commit-tree "$2" $3  # reads the rest of stdin
-	) || die "Can't copy commit $1"
+	) || die "fatal: can't copy commit $1"
 }
 
 # Usage: add_msg DIR LATEST_OLD LATEST_NEW
@@ -718,11 +763,11 @@ ensure_clean () {
 	assert test $# = 0
 	if ! git diff-index HEAD --exit-code --quiet 2>&1
 	then
-		die "Working tree has modifications.  Cannot add."
+		die "fatal: working tree has modifications.  Cannot add."
 	fi
 	if ! git diff-index --cached HEAD --exit-code --quiet 2>&1
 	then
-		die "Index has modifications.  Cannot add."
+		die "fatal: index has modifications.  Cannot add."
 	fi
 }
 
@@ -730,7 +775,7 @@ ensure_clean () {
 ensure_valid_ref_format () {
 	assert test $# = 1
 	git check-ref-format "refs/heads/$1" ||
-		die "'$1' does not look like a ref"
+		die "fatal: '$1' does not look like a ref"
 }
 
 # Usage: process_split_commit REV PARENTS
@@ -796,7 +841,7 @@ cmd_add () {
 	if test $# -eq 1
 	then
 		git rev-parse -q --verify "$1^{commit}" >/dev/null ||
-			die "'$1' does not refer to a commit"
+			die "fatal: '$1' does not refer to a commit"
 
 		cmd_add_commit "$@"
 
@@ -811,7 +856,7 @@ cmd_add () {
 
 		cmd_add_repository "$@"
 	else
-		say >&2 "error: parameters were '$*'"
+		say >&2 "fatal: parameters were '$*'"
 		die "Provide either a commit or a repository and commit."
 	fi
 }
@@ -843,7 +888,7 @@ cmd_add_commit () {
 	git checkout -- "$dir" || exit $?
 	tree=$(git write-tree) || exit $?
 
-	headrev=$(git rev-parse HEAD) || exit $?
+	headrev=$(git rev-parse --verify HEAD) || exit $?
 	if test -n "$headrev" && test "$headrev" != "$rev"
 	then
 		headp="-p $headrev"
@@ -866,17 +911,22 @@ cmd_add_commit () {
 	say >&2 "Added dir '$dir'"
 }
 
-# Usage: cmd_split [REV]
+# Usage: cmd_split [REV] [REPOSITORY]
 cmd_split () {
 	if test $# -eq 0
 	then
 		rev=$(git rev-parse HEAD)
-	elif test $# -eq 1
+	elif test $# -eq 1 -o $# -eq 2
 	then
 		rev=$(git rev-parse -q --verify "$1^{commit}") ||
-			die "'$1' does not refer to a commit"
+			die "fatal: '$1' does not refer to a commit"
 	else
-		die "You must provide exactly one revision.  Got: '$*'"
+		die "fatal: you must provide exactly one revision, and optionnally a repository.  Got: '$*'"
+	fi
+	repository=""
+	if test "$#" = 2
+	then
+		repository="$2"
 	fi
 
 	if test -n "$arg_split_rejoin"
@@ -900,7 +950,7 @@ cmd_split () {
 		done || exit $?
 	fi
 
-	unrevs="$(find_existing_splits "$dir" "$rev")" || exit $?
+	unrevs="$(find_existing_splits "$dir" "$rev" "$repository")" || exit $?
 
 	# We can't restrict rev-list to only $dir here, because some of our
 	# parents have the $dir contents the root, and those won't match.
@@ -919,7 +969,7 @@ cmd_split () {
 	latest_new=$(cache_get latest_new) || exit $?
 	if test -z "$latest_new"
 	then
-		die "No new revisions were found"
+		die "fatal: no new revisions were found"
 	fi
 
 	if test -n "$arg_split_rejoin"
@@ -940,7 +990,7 @@ cmd_split () {
 		then
 			if ! git merge-base --is-ancestor "$arg_split_branch" "$latest_new"
 			then
-				die "Branch '$arg_split_branch' is not an ancestor of commit '$latest_new'."
+				die "fatal: branch '$arg_split_branch' is not an ancestor of commit '$latest_new'."
 			fi
 			action='Updated'
 		else
@@ -954,20 +1004,25 @@ cmd_split () {
 	exit 0
 }
 
-# Usage: cmd_merge REV
+# Usage: cmd_merge REV [REPOSITORY]
 cmd_merge () {
-	test $# -eq 1 ||
-		die "You must provide exactly one revision.  Got: '$*'"
+	test $# -eq 1 -o $# -eq 2 ||
+		die "fatal: you must provide exactly one revision, and optionally a repository. Got: '$*'"
 	rev=$(git rev-parse -q --verify "$1^{commit}") ||
-		die "'$1' does not refer to a commit"
+		die "fatal: '$1' does not refer to a commit"
+	repository=""
+	if test "$#" = 2
+	then
+		repository="$2"
+	fi
 	ensure_clean
 
 	if test -n "$arg_addmerge_squash"
 	then
-		first_split="$(find_latest_squash "$dir")" || exit $?
+		first_split="$(find_latest_squash "$dir" "$repository")" || exit $?
 		if test -z "$first_split"
 		then
-			die "Can't squash-merge: '$dir' was never added."
+			die "fatal: can't squash-merge: '$dir' was never added."
 		fi
 		set $first_split
 		old=$1
@@ -995,19 +1050,21 @@ cmd_merge () {
 cmd_pull () {
 	if test $# -ne 2
 	then
-		die "You must provide <repository> <ref>"
+		die "fatal: you must provide <repository> <ref>"
 	fi
+	repository="$1"
+	ref="$2"
 	ensure_clean
-	ensure_valid_ref_format "$2"
-	git fetch "$@" || exit $?
-	cmd_merge FETCH_HEAD
+	ensure_valid_ref_format "$ref"
+	git fetch "$repository" "$ref" || exit $?
+	cmd_merge FETCH_HEAD "$repository"
 }
 
 # Usage: cmd_push REPOSITORY [+][LOCALREV:]REMOTEREF
 cmd_push () {
 	if test $# -ne 2
 	then
-		die "You must provide <repository> <refspec>"
+		die "fatal: you must provide <repository> <refspec>"
 	fi
 	if test -e "$dir"
 	then
@@ -1022,13 +1079,13 @@ cmd_push () {
 		fi
 		ensure_valid_ref_format "$remoteref"
 		localrev_presplit=$(git rev-parse -q --verify "$localrevname_presplit^{commit}") ||
-			die "'$localrevname_presplit' does not refer to a commit"
+			die "fatal: '$localrevname_presplit' does not refer to a commit"
 
 		echo "git push using: " "$repository" "$refspec"
-		localrev=$(cmd_split "$localrev_presplit") || die
+		localrev=$(cmd_split "$localrev_presplit" "$repository") || die
 		git push "$repository" "$localrev":"refs/heads/$remoteref"
 	else
-		die "'$dir' must already exist. Try 'git subtree add'."
+		die "fatal: '$dir' must already exist. Try 'git subtree add'."
 	fi
 }
 
diff --git a/contrib/subtree/git-subtree.txt b/contrib/subtree/git-subtree.txt
index 9cddfa26540..004abf415b8 100644
--- a/contrib/subtree/git-subtree.txt
+++ b/contrib/subtree/git-subtree.txt
@@ -11,7 +11,7 @@ SYNOPSIS
 [verse]
 'git subtree' [<options>] -P <prefix> add <local-commit>
 'git subtree' [<options>] -P <prefix> add <repository> <remote-ref>
-'git subtree' [<options>] -P <prefix> merge <local-commit>
+'git subtree' [<options>] -P <prefix> merge <local-commit> [<repository>]
 'git subtree' [<options>] -P <prefix> split [<local-commit>]
 
 [verse]
@@ -76,7 +76,7 @@ add <repository> <remote-ref>::
 	only a single commit from the subproject, rather than its
 	entire history.
 
-merge <local-commit>::
+merge <local-commit> [<repository>]::
 	Merge recent changes up to <local-commit> into the <prefix>
 	subtree.  As with normal 'git merge', this doesn't
 	remove your own local changes; it just merges those
@@ -88,8 +88,13 @@ If you use '--squash', the merge direction doesn't always have to be
 forward; you can use this command to go back in time from v2.5 to v2.4,
 for example.  If your merge introduces a conflict, you can resolve it in
 the usual ways.
++
+When using '--squash', and the previous merge with '--squash' merged an
+annotated tag of the subtree repository, that tag needs to be available locally.
+If <repository> is given, a missing tag will automatically be fetched from that
+repository.
 
-split [<local-commit>]::
+split [<local-commit>] [<repository>]::
 	Extract a new, synthetic project history from the
 	history of the <prefix> subtree of <local-commit>, or of
 	HEAD if no <local-commit> is given.  The new history
@@ -109,6 +114,11 @@ settings passed to 'split' (such as '--annotate') are the same.
 Because of this, if you add new commits and then re-split, the new
 commits will be attached as commits on top of the history you
 generated last time, so 'git merge' and friends will work as expected.
++
+When a previous merge with '--squash' merged an annotated tag of the
+subtree repository, that tag needs to be available locally.
+If <repository> is given, a missing tag will automatically be fetched from that
+repository.
 
 pull <repository> <remote-ref>::
 	Exactly like 'merge', but parallels 'git pull' in that
diff --git a/contrib/subtree/t/t7900-subtree.sh b/contrib/subtree/t/t7900-subtree.sh
index 1c1f76f04aa..341c169eca7 100755
--- a/contrib/subtree/t/t7900-subtree.sh
+++ b/contrib/subtree/t/t7900-subtree.sh
@@ -43,6 +43,30 @@ last_commit_subject () {
 	git log --pretty=format:%s -1
 }
 
+# Upon 'git subtree add|merge --squash' of an annotated tag,
+# pre-2.32.0 versions of 'git subtree' would write the hash of the tag
+# (sub1 below), instead of the commit (sub1^{commit}) in the
+# "git-subtree-split" trailer.
+# We immitate this behaviour below using a replace ref.
+# This function creates 3 repositories:
+# - $1
+# - $1-sub (added as subtree "sub" in $1)
+# - $1-clone (clone of $1)
+test_create_pre2_32_repo () {
+	subtree_test_create_repo "$1" &&
+	subtree_test_create_repo "$1-sub" &&
+	test_commit -C "$1" main1 &&
+	test_commit -C "$1-sub" --annotate sub1 &&
+	git -C "$1" subtree add --prefix="sub" --squash "../$1-sub" sub1 &&
+	tag=$(git -C "$1" rev-parse FETCH_HEAD) &&
+	commit=$(git -C "$1" rev-parse FETCH_HEAD^{commit}) &&
+	git -C "$1" log -1 --format=%B HEAD^2 >msg &&
+	test_commit -C "$1-sub" --annotate sub2 &&
+	git clone --no-local "$1" "$1-clone" &&
+	new_commit=$(cat msg | sed -e "s/$commit/$tag/" | git -C "$1-clone" commit-tree HEAD^2^{tree}) &&
+	git -C "$1-clone" replace HEAD^2 $new_commit
+}
+
 test_expect_success 'shows short help text for -h' '
 	test_expect_code 129 git subtree -h >out 2>err &&
 	test_must_be_empty err &&
@@ -264,6 +288,13 @@ test_expect_success 'merge new subproj history into subdir/ with a slash appende
 	)
 '
 
+test_expect_success 'merge with --squash after annotated tag was added/merged with --squash pre-v2.32.0 ' '
+	test_create_pre2_32_repo "$test_count" &&
+	git -C "$test_count-clone" fetch "../$test_count-sub" sub2  &&
+	test_must_fail git -C "$test_count-clone" subtree merge --prefix="sub" --squash FETCH_HEAD &&
+	git -C "$test_count-clone" subtree merge --prefix="sub" --squash FETCH_HEAD  "../$test_count-sub"
+'
+
 #
 # Tests for 'git subtree split'
 #
@@ -277,7 +308,7 @@ test_expect_success 'split requires option --prefix' '
 		cd "$test_count" &&
 		git fetch ./"sub proj" HEAD &&
 		git subtree add --prefix="sub dir" FETCH_HEAD &&
-		echo "You must provide the --prefix option." >expected &&
+		echo "fatal: you must provide the --prefix option." >expected &&
 		test_must_fail git subtree split >actual 2>&1 &&
 		test_debug "printf '"expected: "'" &&
 		test_debug "cat expected" &&
@@ -296,7 +327,7 @@ test_expect_success 'split requires path given by option --prefix must exist' '
 		cd "$test_count" &&
 		git fetch ./"sub proj" HEAD &&
 		git subtree add --prefix="sub dir" FETCH_HEAD &&
-		echo "'\''non-existent-directory'\'' does not exist; use '\''git subtree add'\''" >expected &&
+		echo "fatal: '\''non-existent-directory'\'' does not exist; use '\''git subtree add'\''" >expected &&
 		test_must_fail git subtree split --prefix=non-existent-directory >actual 2>&1 &&
 		test_debug "printf '"expected: "'" &&
 		test_debug "cat expected" &&
@@ -551,6 +582,12 @@ test_expect_success 'split "sub dir"/ with --branch for an incompatible branch'
 	)
 '
 
+test_expect_success 'split after annotated tag was added/merged with --squash pre-v2.32.0' '
+	test_create_pre2_32_repo "$test_count" &&
+	test_must_fail git -C "$test_count-clone" subtree split --prefix="sub" HEAD &&
+	git -C "$test_count-clone" subtree split --prefix="sub" HEAD "../$test_count-sub"
+'
+
 #
 # Tests for 'git subtree pull'
 #
@@ -570,7 +607,7 @@ test_expect_success 'pull requires option --prefix' '
 		cd "$test_count" &&
 		test_must_fail git subtree pull ./"sub proj" HEAD >out 2>err &&
 
-		echo "You must provide the --prefix option." >expected &&
+		echo "fatal: you must provide the --prefix option." >expected &&
 		test_must_be_empty out &&
 		test_cmp expected err
 	)
@@ -584,7 +621,7 @@ test_expect_success 'pull requires path given by option --prefix must exist' '
 	(
 		test_must_fail git subtree pull --prefix="sub dir" ./"sub proj" HEAD >out 2>err &&
 
-		echo "'\''sub dir'\'' does not exist; use '\''git subtree add'\''" >expected &&
+		echo "fatal: '\''sub dir'\'' does not exist; use '\''git subtree add'\''" >expected &&
 		test_must_be_empty out &&
 		test_cmp expected err
 	)
@@ -630,6 +667,11 @@ test_expect_success 'pull rejects flags for split' '
 	)
 '
 
+test_expect_success 'pull with --squash after annotated tag was added/merged with --squash pre-v2.32.0 ' '
+	test_create_pre2_32_repo "$test_count" &&
+	git -C "$test_count-clone" subtree -d pull --prefix="sub" --squash "../$test_count-sub" sub2
+'
+
 #
 # Tests for 'git subtree push'
 #
@@ -643,7 +685,7 @@ test_expect_success 'push requires option --prefix' '
 		cd "$test_count" &&
 		git fetch ./"sub proj" HEAD &&
 		git subtree add --prefix="sub dir" FETCH_HEAD &&
-		echo "You must provide the --prefix option." >expected &&
+		echo "fatal: you must provide the --prefix option." >expected &&
 		test_must_fail git subtree push "./sub proj" from-mainline >actual 2>&1 &&
 		test_debug "printf '"expected: "'" &&
 		test_debug "cat expected" &&
@@ -662,7 +704,7 @@ test_expect_success 'push requires path given by option --prefix must exist' '
 		cd "$test_count" &&
 		git fetch ./"sub proj" HEAD &&
 		git subtree add --prefix="sub dir" FETCH_HEAD &&
-		echo "'\''non-existent-directory'\'' does not exist; use '\''git subtree add'\''" >expected &&
+		echo "fatal: '\''non-existent-directory'\'' does not exist; use '\''git subtree add'\''" >expected &&
 		test_must_fail git subtree push --prefix=non-existent-directory "./sub proj" from-mainline >actual 2>&1 &&
 		test_debug "printf '"expected: "'" &&
 		test_debug "cat expected" &&
@@ -953,6 +995,12 @@ test_expect_success 'push "sub dir"/ with a local rev' '
 	)
 '
 
+test_expect_success 'push after annotated tag was added/merged with --squash pre-v2.32.0' '
+	test_create_pre2_32_repo "$test_count" &&
+	test_create_commit "$test_count-clone" sub/main-sub1 &&
+	git -C "$test_count-clone" subtree push --prefix="sub" "../$test_count-sub" from-mainline
+'
+
 #
 # Validity checking
 #
diff --git a/t/test-lib-functions.sh b/t/test-lib-functions.sh
index 527a7145000..adc0fb6330c 100644
--- a/t/test-lib-functions.sh
+++ b/t/test-lib-functions.sh
@@ -273,13 +273,13 @@ debug () {
 # <file>, <contents>, and <tag> all default to <message>.
 
 test_commit () {
-	notick= &&
-	echo=echo &&
-	append= &&
-	author= &&
-	signoff= &&
-	indir= &&
-	tag=light &&
+	local notick= &&
+	local echo=echo &&
+	local append= &&
+	local author= &&
+	local signoff= &&
+	local indir= &&
+	local tag=light &&
 	while test $# != 0
 	do
 		case "$1" in
@@ -322,7 +322,7 @@ test_commit () {
 		shift
 	done &&
 	indir=${indir:+"$indir"/} &&
-	file=${2:-"$1.t"} &&
+	local file=${2:-"$1.t"} &&
 	if test -n "$append"
 	then
 		$echo "${3-$1}" >>"$indir$file"