Fix SC2162

I'm pretty sure shadow(5) guarantees this won't happen but best to be safe

wayblue-fix-89.sh

@@ -24,8 +24,7 @@
 # that the cause is this disparity and that it will be smoothed out when
 # systemd-sysusers next runs
 #
-set -e
-set -o pipefail
+set -euo pipefail
 
 # Iterate over each file we're interested in
 for file in /etc/shadow /etc/gshadow; do
@@ -42,7 +41,10 @@ for file in /etc/shadow /etc/gshadow; do
 	# Prelim checks succeeded, move forward
 	echo "Parsing $file for junk"
 	# Read each line in the file to iterate over it
-	while read line; do
+	while read -r line; do
+		# This should never happen, but if for some reason we get an empty line,
+		# continue
+		[ -z "$line" ] && continue
 		# Per shadow(5), we are guaranteed that all characters leading up to the
 		# first colon are the user's/group's name. To that end, we'll do a bash
 		# string substitution to extract that first column.
@@ -59,7 +61,7 @@ for file in /etc/shadow /etc/gshadow; do
 				;;
 			*)
 				echo "Unknown file to parse for junk: $file"
-				exit
+				exit 101
 				;;
 		esac
 		# Now, we use getent to find a match for the shadow entry. It's at this point
@@ -108,5 +110,7 @@ for file in /etc/shadow /etc/gshadow; do
 				"/^$name:/d" \
 				"$file"
 		fi
-	done < "$file"
+	# Not useless use of cat. We're buffering the file here to avoid conditions
+	# where we edit the file we're reading and face issues.
+	done < <(cat "$file")
 done