Merge branch 'sk/test-commit-body-helper' into jch

A new test helper commit_body() has been introduced to print the message body of a commit, and various tests have been updated to use it instead of spelling out the command pipeline manually and losing the exit status of the 'git cat-file' command on the upstream of the pipe. * sk/test-commit-body-helper: t: use commit_body to extract commit message bodies test-lib-functions: add commit_body helper
2026-08-09 01:21:47 +00:00 · 2026-08-07 14:48:07 -07:00
parent 30d2bc2f20 9539653b71
commit 39ec52f5b6
15 changed files with 91 additions and 123 deletions
--- a/t/README
+++ b/t/README
@@ -945,6 +945,17 @@ see test-lib-functions.sh for the full list and their options.
   Merges the given rev using the given message.  Like test_commit,
   creates a tag and calls test_tick before committing.

+ - commit_body <rev>
+
+   Print the message body of <rev>, i.e. the contents of its commit
+   object with the header removed.  Use this instead of piping
+   "git cat-file commit" into "sed", which would hide a failure of
+   the git command.
+
+   Example:
+
+	commit_body HEAD >actual
+
 - test_set_prereq <prereq>

   Set a test prerequisite to be used later with test_have_prereq. The
--- a/t/t3404-rebase-interactive.sh
+++ b/t/t3404-rebase-interactive.sh
@@ -484,7 +484,7 @@ test_expect_success 'squash and fixup generate correct log messages' '
 			EXPECT_HEADER_COUNT=4 \
 			git rebase -i $base
 	) &&
-	git cat-file commit HEAD | sed -e 1,/^\$/d > actual-squash-fixup &&
+	commit_body HEAD >actual-squash-fixup &&
 	test_cmp expect-squash-fixup actual-squash-fixup &&
 	git cat-file commit HEAD@{2} >actual &&
 	test_grep "^# This is a combination of 3 commits\." actual &&
--- a/t/t3405-rebase-malformed.sh
+++ b/t/t3405-rebase-malformed.sh
@@ -37,7 +37,7 @@ test_expect_success setup '
 	test_tick &&
 	git commit -F F &&

-	git cat-file commit HEAD | sed -e "1,/^\$/d" >F0 &&
+	commit_body HEAD >F0 &&

 	git checkout diff-in-message &&
 	echo "commit log message containing a diff" >G &&
@@ -48,7 +48,7 @@ test_expect_success setup '
 	test_tick &&
 	git commit -F G &&

-	git cat-file commit HEAD | sed -e "1,/^\$/d" >G0 &&
+	commit_body HEAD >G0 &&

 	git checkout empty-message-merge &&
 	echo file3 >file3 &&
@@ -66,7 +66,7 @@ test_expect_success setup '
 test_expect_success 'rebase commit with multi-line subject' '

 	git rebase main multi-line-subject &&
-	git cat-file commit HEAD | sed -e "1,/^\$/d" >F1 &&
+	commit_body HEAD >F1 &&

 	test_cmp F0 F1 &&
 	test_cmp F F0
@@ -74,7 +74,7 @@ test_expect_success 'rebase commit with multi-line subject' '

 test_expect_success 'rebase commit with diff in message' '
 	git rebase main diff-in-message &&
-	git cat-file commit HEAD | sed -e "1,/^$/d" >G1 &&
+	commit_body HEAD >G1 &&
 	test_cmp G0 G1 &&
 	test_cmp G G0
 '
--- a/t/t3408-rebase-multi-line.sh
+++ b/t/t3408-rebase-multi-line.sh
@@ -50,8 +50,8 @@ test_expect_success rebase '

 	git checkout side &&
 	git rebase main &&
-	git cat-file commit HEAD | sed -e "1,/^\$/d" >actual &&
-	git cat-file commit side@{1} | sed -e "1,/^\$/d" >expect &&
+	commit_body HEAD >actual &&
+	commit_body side@{1} >expect &&
 	test_cmp expect actual

 '
--- a/t/t3434-rebase-i18n.sh
+++ b/t/t3434-rebase-i18n.sh
@@ -27,8 +27,7 @@ fi

 compare_msg () {
 	iconv -f "$2" -t "$3" "$TEST_DIRECTORY/t3434/$1" >expect &&
-	git cat-file commit HEAD >raw &&
-	sed "1,/^$/d" raw >actual &&
+	commit_body HEAD >actual &&
 	test_cmp expect actual
 }

--- a/t/t3900-i18n-commit.sh
+++ b/t/t3900-i18n-commit.sh
@@ -232,8 +232,8 @@ test_commit_autosquash_multi_encoding () {
 		git rev-list HEAD >actual &&
 		test_line_count = 3 actual &&
 		iconv -f $old -t UTF-8 "$TEST_DIRECTORY"/t3900/$msg >expect &&
-		git cat-file commit HEAD^ >raw &&
-		(sed "1,/^$/d" raw | iconv -f $new -t utf-8) >actual &&
+		commit_body HEAD^ >raw &&
+		iconv -f $new -t utf-8 <raw >actual &&
 		test_cmp expect actual
 	'
 }
--- a/t/t4150-am.sh
+++ b/t/t4150-am.sh
@@ -1018,7 +1018,7 @@ test_expect_success 'am -s unexpected trailer block' '
 	Signed-off-by: J C H <j@c.h>
 	EOF
 	git commit -F msg &&
-	git cat-file commit HEAD | sed -e "1,/^$/d" >original &&
+	commit_body HEAD >original &&
 	git format-patch --stdout -1 >patch &&

 	git reset --hard HEAD^ &&
@@ -1027,7 +1027,7 @@ test_expect_success 'am -s unexpected trailer block' '
 		cat original &&
 		echo "Signed-off-by: $GIT_COMMITTER_NAME <$GIT_COMMITTER_EMAIL>"
 	) >expect &&
-	git cat-file commit HEAD | sed -e "1,/^$/d" >actual &&
+	commit_body HEAD >actual &&
 	test_cmp expect actual &&

 	cat >msg <<-\EOF &&
@@ -1038,7 +1038,7 @@ test_expect_success 'am -s unexpected trailer block' '
 	EOF
 	git reset HEAD^ &&
 	git commit -F msg file &&
-	git cat-file commit HEAD | sed -e "1,/^$/d" >original &&
+	commit_body HEAD >original &&
 	git format-patch --stdout -1 >patch &&

 	git reset --hard HEAD^ &&
@@ -1049,7 +1049,7 @@ test_expect_success 'am -s unexpected trailer block' '
 		echo &&
 		echo "Signed-off-by: $GIT_COMMITTER_NAME <$GIT_COMMITTER_EMAIL>"
 	) >expect &&
-	git cat-file commit HEAD | sed -e "1,/^$/d" >actual &&
+	commit_body HEAD >actual &&
 	test_cmp expect actual
 '

--- a/t/t7500-commit-template-squash-signoff.sh
+++ b/t/t7500-commit-template-squash-signoff.sh
@@ -59,7 +59,7 @@ test_expect_success 'nonexistent template file in config should return error' '
 test_expect_success 'nonexistent optional template file in config' '
 	test_config commit.template ":(optional)$(pwd)"/notexist &&
 	GIT_EDITOR="echo hello >" git commit --allow-empty &&
-	git cat-file commit HEAD | sed -e "1,/^$/d" >actual &&
+	commit_body HEAD >actual &&
 	echo hello >expect &&
 	test_cmp expect actual
 '
@@ -204,7 +204,7 @@ EOF
 test_expect_success '--signoff' '
 	echo "yet another content *narf*" >> foo &&
 	echo "zort" | git commit -s -F - foo &&
-	git cat-file commit HEAD | sed "1,/^\$/d" > output &&
+	commit_body HEAD >output &&
 	test_cmp expect output
 '

--- a/t/t7501-commit-basic-functionality.sh
+++ b/t/t7501-commit-basic-functionality.sh
@@ -491,8 +491,7 @@ test_expect_success 'sign off (1)' '
 	echo 1 >positive &&
 	git add positive &&
 	git commit -s -m "thank you" &&
-	git cat-file commit HEAD >commit &&
-	sed -e "1,/^\$/d" commit >actual &&
+	commit_body HEAD >actual &&
 	(
 		echo thank you &&
 		echo &&
@@ -511,8 +510,7 @@ test_expect_success 'sign off (2)' '
 	git commit -s -m "thank you

 $existing" &&
-	git cat-file commit HEAD >commit &&
-	sed -e "1,/^\$/d" commit >actual &&
+	commit_body HEAD >actual &&
 	(
 		echo thank you &&
 		echo &&
@@ -532,8 +530,7 @@ test_expect_success 'signoff gap' '
 	git commit -s -m "welcome

 $alt" &&
-	git cat-file commit HEAD >commit &&
-	sed -e "1,/^\$/d" commit >actual &&
+	commit_body HEAD >actual &&
 	(
 		echo welcome &&
 		echo &&
@@ -553,8 +550,7 @@ test_expect_success 'signoff gap 2' '

 We have now
 $alt" &&
-	git cat-file commit HEAD >commit &&
-	sed -e "1,/^\$/d" commit >actual &&
+	commit_body HEAD >actual &&
 	(
 		echo welcome &&
 		echo &&
@@ -575,8 +571,7 @@ test_expect_success 'signoff respects trailer config' '

 non-trailer line
 Myfooter: x" &&
-	git cat-file commit HEAD >commit &&
-	sed -e "1,/^\$/d" commit >actual &&
+	commit_body HEAD >actual &&
 	(
 		echo subject &&
 		echo &&
@@ -593,8 +588,7 @@ Myfooter: x" &&

 non-trailer line
 Myfooter: x" &&
-	git cat-file commit HEAD >commit &&
-	sed -e "1,/^\$/d" commit >actual &&
+	commit_body HEAD >actual &&
 	(
 		echo subject &&
 		echo &&
@@ -626,8 +620,7 @@ test_expect_success 'multiple -m' '
 	>negative &&
 	git add negative &&
 	git commit -m "one" -m "two" -m "three" &&
-	git cat-file commit HEAD >commit &&
-	sed -e "1,/^\$/d" commit >actual &&
+	commit_body HEAD >actual &&
 	(
 		echo one &&
 		echo &&
--- a/t/t7502-commit-porcelain.sh
+++ b/t/t7502-commit-porcelain.sh
@@ -175,8 +175,7 @@ test_expect_success 'commit --trailer with "="' '
 	Reported-by: C3 E3
 	Mentored-by: C4 E4
 	EOF
-	git cat-file commit HEAD >commit.msg &&
-	sed -e "1,/^\$/d" commit.msg >actual &&
+	commit_body HEAD >actual &&
 	test_cmp expected actual
 '

@@ -195,8 +194,7 @@ test_expect_success 'commit --trailer with -c and "replace" as ifexists' '
 		commit --trailer "Mentored-by: C4 E4" \
 		 --trailer "Helped-by: C3 E3" \
 		--amend &&
-	git cat-file commit HEAD >commit.msg &&
-	sed -e "1,/^\$/d"  commit.msg >actual &&
+	commit_body HEAD >actual &&
 	test_cmp expected actual
 '

@@ -217,8 +215,7 @@ test_expect_success 'commit --trailer with -c and "add" as ifexists' '
 		commit --trailer "Reported-by: C3 E3" \
 		--trailer "Mentored-by: C4 E4" \
 		--amend &&
-	git cat-file commit HEAD >commit.msg &&
-	sed -e "1,/^\$/d"  commit.msg >actual &&
+	commit_body HEAD >actual &&
 	test_cmp expected actual
 '

@@ -238,8 +235,7 @@ test_expect_success 'commit --trailer with -c and "donothing" as ifexists' '
 		commit --trailer "Mentored-by: C5 E5" \
 		--trailer "Reviewed-by: C6 E6" \
 		--amend &&
-	git cat-file commit HEAD >commit.msg &&
-	sed -e "1,/^\$/d"  commit.msg >actual &&
+	commit_body HEAD >actual &&
 	test_cmp expected actual
 '

@@ -259,8 +255,7 @@ test_expect_success 'commit --trailer with -c and "addIfDifferent" as ifexists'
 		commit --trailer "Reported-by: C3 E3" \
 		--trailer "Mentored-by: C5 E5" \
 		--amend &&
-	git cat-file commit HEAD >commit.msg &&
-	sed -e "1,/^\$/d"  commit.msg >actual &&
+	commit_body HEAD >actual &&
 	test_cmp expected actual
 '

@@ -280,8 +275,7 @@ test_expect_success 'commit --trailer with -c and "addIfDifferentNeighbor" as if
 		commit --trailer "Mentored-by: C4 E4" \
 		--trailer "Reported-by: C3 E3" \
 		--amend &&
-	git cat-file commit HEAD >commit.msg &&
-	sed -e "1,/^\$/d"  commit.msg >actual &&
+	commit_body HEAD >actual &&
 	test_cmp expected actual
 '

@@ -302,8 +296,7 @@ test_expect_success 'commit --trailer with -c and "end" as where' '
 		commit --trailer "Reported-by: C3 E3" \
 		--trailer "Mentored-by: C4 E4" \
 		--amend &&
-	git cat-file commit HEAD >commit.msg &&
-	sed -e "1,/^\$/d" commit.msg >actual &&
+	commit_body HEAD >actual &&
 	test_cmp expected actual
 '

@@ -323,8 +316,7 @@ test_expect_success 'commit --trailer with -c and "start" as where' '
 		commit --trailer "Signed-off-by: C O Mitter <committer@example.com>" \
 		--trailer "Signed-off-by: C1 E1" \
 		--amend &&
-	git cat-file commit HEAD >commit.msg &&
-	sed -e "1,/^\$/d" commit.msg >actual &&
+	commit_body HEAD >actual &&
 	test_cmp expected actual
 '

@@ -344,8 +336,7 @@ test_expect_success 'commit --trailer with -c and "after" as where' '
 		commit --trailer "Mentored-by: C4 E4" \
 		--trailer "Mentored-by: C5 E5" \
 		--amend &&
-	git cat-file commit HEAD >commit.msg &&
-	sed -e "1,/^\$/d" commit.msg >actual &&
+	commit_body HEAD >actual &&
 	test_cmp expected actual
 '

@@ -366,8 +357,7 @@ test_expect_success 'commit --trailer with -c and "before" as where' '
 		commit --trailer "Mentored-by: C3 E3" \
 		--trailer "Mentored-by: C2 E2" \
 		--amend &&
-	git cat-file commit HEAD >commit.msg &&
-	sed -e "1,/^\$/d" commit.msg >actual &&
+	commit_body HEAD >actual &&
 	test_cmp expected actual
 '

@@ -387,8 +377,7 @@ test_expect_success 'commit --trailer with -c and "donothing" as ifmissing' '
 		commit --trailer "Helped-by: C5 E5" \
 		--trailer "Based-by: C6 E6" \
 		--amend &&
-	git cat-file commit HEAD >commit.msg &&
-	sed -e "1,/^\$/d" commit.msg >actual &&
+	commit_body HEAD >actual &&
 	test_cmp expected actual
 '

@@ -409,8 +398,7 @@ test_expect_success 'commit --trailer with -c and "add" as ifmissing' '
 		commit --trailer "Helped-by: C5 E5" \
 		--trailer "Based-by: C6 E6" \
 		--amend &&
-	git cat-file commit HEAD >commit.msg &&
-	sed -e "1,/^\$/d" commit.msg >actual &&
+	commit_body HEAD >actual &&
 	test_cmp expected actual
 '

@@ -424,8 +412,7 @@ test_expect_success 'commit --trailer with -c ack.key ' '
 	EOF
 	git -c trailer.ack.key="Acked-by" \
 		commit --trailer "ack = Peff" -m "hello" &&
-	git cat-file commit HEAD >commit.msg &&
-	sed -e "1,/^\$/d" commit.msg >actual &&
+	commit_body HEAD >actual &&
 	test_cmp expected actual
 '

@@ -440,8 +427,7 @@ test_expect_success 'commit --trailer with -c and ":=#" as separators' '
 	git -c trailer.separators=":=#" \
 		-c trailer.bug.key="Bug #" \
 		commit --trailer "bug = 42" -m "I hate bug" &&
-	git cat-file commit HEAD >commit.msg &&
-	sed -e "1,/^\$/d" commit.msg >actual &&
+	commit_body HEAD >actual &&
 	test_cmp expected actual
 '

@@ -461,8 +447,7 @@ test_expect_success 'commit --trailer with -c and command' '
 		-c trailer.report.command="NAME=\"\$ARG\"; test -n \"\$NAME\" && \
 		git log --author=\"\$NAME\" -1 --format=\"format:%aN <%aE>\" || true" \
 		commit --trailer "report = author" --amend &&
-	git cat-file commit HEAD >commit.msg &&
-	sed -e "1,/^\$/d" commit.msg >actual &&
+	commit_body HEAD >actual &&
 	test_cmp expected actual
 '

@@ -480,8 +465,7 @@ test_expect_success 'commit --trailer not confused by --- separator' '
 		echo &&
 		echo "my-trailer: value"
 	} >expected &&
-	git cat-file commit HEAD >commit.msg &&
-	sed -e "1,/^\$/d" commit.msg >actual &&
+	commit_body HEAD >actual &&
 	test_cmp expected actual
 '

@@ -498,8 +482,7 @@ test_expect_success 'commit --trailer with --verbose' '
 		echo &&
 		echo "my-trailer: value"
 	} >expected &&
-	git cat-file commit HEAD >commit.msg &&
-	sed -e "1,/^\$/d" commit.msg >actual &&
+	commit_body HEAD >actual &&
 	test_cmp expected actual
 '

@@ -508,7 +491,7 @@ test_expect_success 'multiple -m' '
 	>negative &&
 	git add negative &&
 	git commit -m "one" -m "two" -m "three" &&
-	actual=$(git cat-file commit HEAD >tmp && sed -e "1,/^\$/d" tmp && rm tmp) &&
+	actual=$(commit_body HEAD) &&
 	expected=$(test_write_lines "one" "" "two" "" "three") &&
 	test "z$actual" = "z$expected"

@@ -545,8 +528,7 @@ test_expect_success 'cleanup commit messages (verbatim option,-t)' '

 	echo >>negative &&
 	git commit --cleanup=verbatim --no-status -t expect -a &&
-	git cat-file -p HEAD >raw &&
-	sed -e "1,/^\$/d" raw >actual &&
+	commit_body HEAD >actual &&
 	test_cmp expect actual

 '
@@ -555,8 +537,7 @@ test_expect_success 'cleanup commit messages (verbatim option,-F)' '

 	echo >>negative &&
 	git commit --cleanup=verbatim -F expect -a &&
-	git cat-file -p HEAD >raw &&
-	sed -e "1,/^\$/d" raw >actual &&
+	commit_body HEAD >actual &&
 	test_cmp expect actual

 '
@@ -565,8 +546,7 @@ test_expect_success 'cleanup commit messages (verbatim option,-m)' '

 	echo >>negative &&
 	git commit --cleanup=verbatim -m "$mesg_with_comment_and_newlines" -a &&
-	git cat-file -p HEAD >raw &&
-	sed -e "1,/^\$/d" raw >actual &&
+	commit_body HEAD >actual &&
 	test_cmp expect actual

 '
@@ -577,8 +557,7 @@ test_expect_success 'cleanup commit messages (whitespace option,-F)' '
 	test_write_lines "" "# text" "" >text &&
 	echo "# text" >expect &&
 	git commit --cleanup=whitespace -F text -a &&
-	git cat-file -p HEAD >raw &&
-	sed -e "1,/^\$/d" raw >actual &&
+	commit_body HEAD >actual &&
 	test_cmp expect actual

 '
@@ -605,8 +584,7 @@ test_expect_success 'cleanup commit messages (scissors option,-F,-e)' '
 	# to be kept, too
 	EOF
 	git commit --cleanup=scissors -e -F text -a &&
-	git cat-file -p HEAD >raw &&
-	sed -e "1,/^\$/d" raw >actual &&
+	commit_body HEAD >actual &&
 	test_cmp expect actual
 '

@@ -618,8 +596,7 @@ test_expect_success 'cleanup commit messages (scissors option,-F,-e, scissors on
 	to be removed
 	EOF
 	git commit --cleanup=scissors -e -F text -a --allow-empty-message &&
-	git cat-file -p HEAD >raw &&
-	sed -e "1,/^\$/d" raw >actual &&
+	commit_body HEAD >actual &&
 	test_must_be_empty actual
 '

@@ -629,8 +606,7 @@ test_expect_success 'cleanup commit messages (strip option,-F)' '
 	test_write_lines "" "# text" "sample" "" >text &&
 	echo sample >expect &&
 	git commit --cleanup=strip -F text -a &&
-	git cat-file -p HEAD >raw &&
-	sed -e "1,/^\$/d" raw >actual &&
+	commit_body HEAD >actual &&
 	test_cmp expect actual

 '
@@ -849,8 +825,7 @@ test_expect_success 'A single-liner subject with a token plus colon is not a foo

 	git reset --hard &&
 	git commit -s -m "hello: kitty" --allow-empty &&
-	git cat-file commit HEAD >raw &&
-	sed -e "1,/^$/d" raw >actual &&
+	commit_body HEAD >actual &&
 	test_line_count = 3 actual

 '
--- a/t/t7509-commit-authorship.sh
+++ b/t/t7509-commit-authorship.sh
@@ -12,11 +12,6 @@ author_header () {
 	sed -n -e '/^$/q' -e '/^author /p'
 }

-message_body () {
-	git cat-file commit "$1" |
-	sed -e '1,/^$/d'
-}
-
 test_expect_success '-C option copies authorship and message' '
 	test_commit --author Frigate\ \<flying@over.world\> \
 		"Initial Commit" foo Initial Initial &&
@@ -27,8 +22,8 @@ test_expect_success '-C option copies authorship and message' '
 	author_header HEAD >actual &&
 	test_cmp expect actual &&

-	message_body Initial >expect &&
-	message_body HEAD >actual &&
+	commit_body Initial >expect &&
+	commit_body HEAD >actual &&
 	test_cmp expect actual
 '

@@ -40,8 +35,8 @@ test_expect_success '-C option copies only the message with --reset-author' '
 	author_header HEAD >actual &&
 	test_cmp expect actual &&

-	message_body Initial >expect &&
-	message_body HEAD >actual &&
+	commit_body Initial >expect &&
+	commit_body HEAD >actual &&
 	test_cmp expect actual
 '

@@ -62,8 +57,8 @@ test_expect_success '-c option copies only the message with --reset-author' '
 	author_header HEAD >actual &&
 	test_cmp expect actual &&

-	message_body Initial >expect &&
-	message_body HEAD >actual &&
+	commit_body Initial >expect &&
+	commit_body HEAD >actual &&
 	test_cmp expect actual
 '

@@ -77,7 +72,7 @@ test_expect_success '--amend option copies authorship' '
 	test_cmp expect actual &&

 	echo "amend test" >expect &&
-	message_body HEAD >actual &&
+	commit_body HEAD >actual &&
 	test_cmp expect actual
 '

@@ -124,7 +119,7 @@ test_expect_success '--reset-author makes the commit ours even with --amend opti
 	test_cmp expect actual &&

 	echo "Changed again" >expect &&
-	message_body HEAD >actual &&
+	commit_body HEAD >actual &&
 	test_cmp expect actual
 '

@@ -157,7 +152,7 @@ test_expect_success 'commit respects CHERRY_PICK_HEAD and MERGE_MSG' '
 	test_cmp expect actual &&

 	echo "This is a MERGE_MSG" >expect &&
-	message_body HEAD >actual &&
+	commit_body HEAD >actual &&
 	test_cmp expect actual
 '

--- a/t/t7600-merge.sh
+++ b/t/t7600-merge.sh
@@ -332,8 +332,7 @@ test_expect_success 'merge --squash c3 with c7' '
 	# Conflicts:
 	#	file
 	EOF
-	git cat-file commit HEAD >raw &&
-	sed -e "1,/^$/d" raw >actual &&
+	commit_body HEAD >actual &&
 	test_cmp expect actual
 '

@@ -363,8 +362,7 @@ test_expect_success 'merge c3 with c7 with commit.cleanup = scissors' '
 	# Conflicts:
 	#	file
 	EOF
-	git cat-file commit HEAD >raw &&
-	sed -e "1,/^$/d" raw >actual &&
+	commit_body HEAD >actual &&
 	test_cmp expect actual
 '

@@ -387,8 +385,7 @@ test_expect_success 'merge c3 with c7 with --squash commit.cleanup = scissors' '
 	# Conflicts:
 	#	file
 	EOF
-	git cat-file commit HEAD >raw &&
-	sed -e "1,/^$/d" raw >actual &&
+	commit_body HEAD >actual &&
 	test_cmp expect actual
 '

@@ -989,9 +986,8 @@ test_expect_success 'merge --no-ff --edit' '
 	git reset --hard c0 &&
 	EDITOR=./editor git merge --no-ff --edit c1 &&
 	verify_parents $c0 $c1 &&
-	git cat-file commit HEAD >raw &&
-	test_grep "work done on the side branch" raw &&
-	sed "1,/^$/d" >actual raw &&
+	commit_body HEAD >actual &&
+	test_grep "work done on the side branch" actual &&
 	test_cmp expected actual
 '

--- a/t/t7604-merge-custom-message.sh
+++ b/t/t7604-merge-custom-message.sh
@@ -36,16 +36,14 @@ test_expect_success 'setup' '
 test_expect_success 'merge c2 with a custom message' '
 	git reset --hard c1 &&
 	git merge -m "$(cat exp.subject)" c2 &&
-	git cat-file commit HEAD >raw &&
-	sed -e "1,/^$/d" raw >actual &&
+	commit_body HEAD >actual &&
 	test_cmp exp.subject actual
 '

 test_expect_success 'merge --log appends to custom message' '
 	git reset --hard c1 &&
 	git merge --log -m "$(cat exp.subject)" c2 &&
-	git cat-file commit HEAD >raw &&
-	sed -e "1,/^$/d" raw >actual &&
+	commit_body HEAD >actual &&
 	test_cmp exp.log actual
 '

@@ -61,8 +59,7 @@ test_expect_success 'prepare file with comment line and trailing newlines'  '
 test_expect_success 'cleanup commit messages (verbatim option)' '
 	git reset --hard c1 &&
 	git merge --cleanup=verbatim -F expect c2 &&
-	git cat-file commit HEAD >raw &&
-	sed -e "1,/^$/d" raw >actual &&
+	commit_body HEAD >actual &&
 	test_cmp expect actual
 '

@@ -71,8 +68,7 @@ test_expect_success 'cleanup commit messages (whitespace option)' '
 	test_write_lines "" "# text" "" >text &&
 	echo "# text" >expect &&
 	git merge --cleanup=whitespace -F text c2 &&
-	git cat-file commit HEAD >raw &&
-	sed -e "1,/^$/d" raw >actual &&
+	commit_body HEAD >actual &&
 	test_cmp expect actual
 '

@@ -97,8 +93,7 @@ test_expect_success 'cleanup merge messages (scissors option)' '
 	# to be kept, too
 	EOF
 	git merge --cleanup=scissors -e -F text c2 &&
-	git cat-file commit HEAD >raw &&
-	sed -e "1,/^$/d" raw >actual &&
+	commit_body HEAD >actual &&
 	test_cmp expect actual
 '

@@ -107,8 +102,7 @@ test_expect_success 'cleanup commit messages (strip option)' '
 	test_write_lines "" "# text" "sample" "" >text &&
 	echo sample >expect &&
 	git merge --cleanup=strip -F text c2 &&
-	git cat-file commit HEAD >raw &&
-	sed -e "1,/^$/d" raw >actual &&
+	commit_body HEAD >actual &&
 	test_cmp expect actual
 '

--- a/t/t7614-merge-signoff.sh
+++ b/t/t7614-merge-signoff.sh
@@ -45,8 +45,7 @@ test_expect_success 'git merge --signoff adds a sign-off line' '
 	test_commit main-branch-2 file2 2 &&
 	git checkout other-branch &&
 	git merge main --signoff --no-edit &&
-	git cat-file commit HEAD >commit &&
-	sed -e "1,/^\$/d" commit >actual &&
+	commit_body HEAD >actual &&
 	test_cmp expected-signed actual
 '

@@ -56,8 +55,7 @@ test_expect_success 'git merge does not add a sign-off line' '
 	test_commit main-branch-3 file3 3 &&
 	git checkout other-branch &&
 	git merge main --no-edit &&
-	git cat-file commit HEAD >commit &&
-	sed -e "1,/^\$/d" commit >actual &&
+	commit_body HEAD >actual &&
 	test_cmp expected-unsigned actual
 '

@@ -67,8 +65,7 @@ test_expect_success 'git merge --no-signoff flag cancels --signoff flag' '
 	test_commit main-branch-4 file4 4 &&
 	git checkout other-branch &&
 	git merge main --no-edit --signoff --no-signoff &&
-	git cat-file commit HEAD >commit &&
-	sed -e "1,/^\$/d" commit >actual &&
+	commit_body HEAD >actual &&
 	test_cmp expected-unsigned actual
 '

--- a/t/test-lib-functions.sh
+++ b/t/test-lib-functions.sh
@@ -1433,6 +1433,14 @@ test_commit_message () {
 	test_cmp "$msg_file" actual.msg
 }

+# Print the message body of a commit
+# Usage: commit_body <rev>
+commit_body () {
+	git cat-file commit "$1" >.commit &&
+	sed -e "1,/^$/d" .commit &&
+	rm -f .commit
+}
+
 # Compare paths respecting core.ignoreCase
 test_cmp_fspath () {
 	if test "x$1" = "x$2"