From e11494312fb7ec067bdb40f2abf3db7bd60fb3df Mon Sep 17 00:00:00 2001
From: Benjamin Drung <benjamin.drung@canonical.com>
Date: Sun, 19 May 2024 16:36:31 +0200
Subject: [PATCH] mkinitramfs: Simplify pipefail implementation

Echoing shell code that sets the variables `ec1` and `ec2` when
evaluated is way too complicated for implementing pipefail (which is not
available in dash). Just write the exit code to FD 3 instead.

Signed-off-by: Benjamin Drung <benjamin.drung@canonical.com>
---
 mkinitramfs | 31 ++++++++-----------------------
 1 file changed, 8 insertions(+), 23 deletions(-)

diff --git a/mkinitramfs b/mkinitramfs
index 3e5d1b1..d6ce859 100755
--- a/mkinitramfs
+++ b/mkinitramfs
@@ -466,7 +466,6 @@ fi
 
 [ "${verbose}" = y ] && echo "Building cpio ${outfile} initramfs"
 
-(
 # preserve permissions if root builds the image, see #633582
 [ "$(id -ru)" != 0 ] && cpio_owner_root="-R 0:0"
 
@@ -480,34 +479,20 @@ if [ -n "${SOURCE_DATE_EPOCH}" ]; then
 	cpio_reproducible="--reproducible"
 fi
 
-# work around lack of "set -o pipefail" for the following pipe:
-# cd "${DESTDIR}" && find . | LC_ALL=C sort | cpio --quiet $cpio_owner_root $cpio_reproducible -o -H newc >>"${outfile}" || exit 1
-ec1=1
-ec2=1
-exec 3>&1
-eval "$(
-	# http://cfaj.freeshell.org/shell/cus-faq-2.html
-	exec 4>&1 >&3 3>&-
+# work around lack of "set -o pipefail" for pipes.
+# Write exit code to FD 3 in case of a failure to pass it through the pipes.
+{
 	cd  "${DESTDIR}"
 	{
-		find . 4>&-; echo "ec1=$?;" >&4
+		find . || { echo "E: mkinitramfs failure find $?" >&2; echo 1 >&3; exit; }
 	} | {
-		LC_ALL=C sort
+		LC_ALL=C sort || { echo "E: mkinitramfs failure sort $?" >&2; echo 1 >&3; exit; }
 	} | {
 		# shellcheck disable=SC2086
-		cpio --quiet $cpio_owner_root $cpio_reproducible -o -H newc 4>&- >"${__TMPMAINCPIO}"
-		echo "ec2=$?;" >&4
+		cpio --quiet $cpio_owner_root $cpio_reproducible -o -H newc >"${__TMPMAINCPIO}" ||
+			{ echo "E: mkinitramfs failure cpio $?" >&2; echo 1 >&3; exit; }
 	}
-)"
-if [ "$ec1" -ne 0 ]; then
-	echo "E: mkinitramfs failure find $ec1 cpio $ec2" >&2
-	exit "$ec1"
-fi
-if [ "$ec2" -ne 0 ]; then
-	echo "E: mkinitramfs failure cpio $ec2" >&2
-	exit "$ec2"
-fi
-) || exit 1
+} 3>&1 | { read -r exit_code; exit "${exit_code:-0}"; } || exit $?
 
 {
 if [ -s "${__TMPEARLYCPIO}" ]; then