From 9ce639c76f567c401c37bc10322ca7ddc7129681 Mon Sep 17 00:00:00 2001
From: Patrick Steinhardt <ps@pks.im>
Date: Fri, 20 Feb 2026 09:26:00 +0100
Subject: [PATCH] t40xx: don't use iconv(1) without ICONV prereq

We've got a couple of tests related to diffs in t40xx that use the
iconv(1) executable to convert the encoding of a commit message. All of
these tests are prepared to handle a missing ICONV prereq, in which case
they will simply use UTF-8 encoding.

But even if the ICONV prerequisite has failed we try to use the iconv(1)
executable, even though it's not safe to assume that the executable
exists in that case. And besides that, it's also unnecessary to use
iconv(1) in the first place, as we would only use it to convert from
UTF-8 to UTF-8, which should be equivalent to a no-op.

Fix the issue and skip the call to iconv(1) in case the prerequisite is
not set. This makes tests work on systems that don't have iconv at all.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 t/t4041-diff-submodule-option.sh             | 8 ++++++--
 t/t4059-diff-submodule-not-initialized.sh    | 8 ++++++--
 t/t4060-diff-submodule-option-diff-format.sh | 8 ++++++--
 3 files changed, 18 insertions(+), 6 deletions(-)

diff --git a/t/t4041-diff-submodule-option.sh b/t/t4041-diff-submodule-option.sh
index 4d4aa1650f..4dd4954260 100755
--- a/t/t4041-diff-submodule-option.sh
+++ b/t/t4041-diff-submodule-option.sh
@@ -37,8 +37,12 @@ add_file () {
 			test_tick &&
 			# "git commit -m" would break MinGW, as Windows refuse to pass
 			# $test_encoding encoded parameter to git.
-			echo "Add $name ($added $name)" | iconv -f utf-8 -t $test_encoding |
-			git -c "i18n.commitEncoding=$test_encoding" commit -F -
+			message="Add $name ($added $name)" &&
+			if test_have_prereq ICONV
+			then
+				message=$(echo "$message" | iconv -f utf-8 -t $test_encoding)
+			fi &&
+			echo "$message" | git -c "i18n.commitEncoding=$test_encoding" commit -F -
 		done >/dev/null &&
 		git rev-parse --short --verify HEAD
 	)
diff --git a/t/t4059-diff-submodule-not-initialized.sh b/t/t4059-diff-submodule-not-initialized.sh
index 0fe81056d5..bb902ce94d 100755
--- a/t/t4059-diff-submodule-not-initialized.sh
+++ b/t/t4059-diff-submodule-not-initialized.sh
@@ -35,8 +35,12 @@ add_file () {
 			test_tick &&
 			# "git commit -m" would break MinGW, as Windows refuse to pass
 			# $test_encoding encoded parameter to git.
-			echo "Add $name ($added $name)" | iconv -f utf-8 -t $test_encoding |
-			git -c "i18n.commitEncoding=$test_encoding" commit -F -
+			message="Add $name ($added $name)" &&
+			if test_have_prereq ICONV
+			then
+				message=$(echo "$message" | iconv -f utf-8 -t $test_encoding)
+			fi &&
+			echo "$message" | git -c "i18n.commitEncoding=$test_encoding" commit -F -
 		done >/dev/null &&
 		git rev-parse --short --verify HEAD
 	)
diff --git a/t/t4060-diff-submodule-option-diff-format.sh b/t/t4060-diff-submodule-option-diff-format.sh
index dbfeb7470b..d8f9213255 100755
--- a/t/t4060-diff-submodule-option-diff-format.sh
+++ b/t/t4060-diff-submodule-option-diff-format.sh
@@ -35,8 +35,12 @@ add_file () {
 			test_tick &&
 			# "git commit -m" would break MinGW, as Windows refuse to pass
 			# $test_encoding encoded parameter to git.
-			echo "Add $name ($added $name)" | iconv -f utf-8 -t $test_encoding |
-			git -c "i18n.commitEncoding=$test_encoding" commit -F -
+			message="Add $name ($added $name)" &&
+			if test_have_prereq ICONV
+			then
+				message=$(echo "$message" | iconv -f utf-8 -t $test_encoding)
+			fi &&
+			echo "$message" | git -c "i18n.commitEncoding=$test_encoding" commit -F -
 		done >/dev/null &&
 		git rev-parse --short --verify HEAD
 	)