make sure input line is set before doing things

spiffworkflow-backend/bin/login_with_user_list

@@ -7,7 +7,10 @@ function error_handler() {
 trap 'error_handler ${LINENO} $?' ERR
 set -o errtrace -o errexit -o nounset -o pipefail
 
-script_dir="$( cd -- "$(dirname "$0")" >/dev/null 2>&1 ; pwd -P )"
+script_dir="$(
+  cd -- "$(dirname "$0")" >/dev/null 2>&1
+  pwd -P
+)"
 
 if [[ -z "${KEYCLOAK_BASE_URL:-}" ]]; then
   export KEYCLOAK_BASE_URL=http://localhost:7002
@@ -24,9 +27,11 @@ fi
 export REALM_NAME=${2-spiffworkflow}
 
 while read -r input_line; do
-  if ! grep -qE '(^#|email)' <<<"$input_line" ; then
+  if [[ -n "$input_line" ]]; then
+    if ! grep -qE '(^#|email)' <<<"$input_line"; then
       username=$(awk -F '@' '{print $1}' <<<"$input_line")
       password=$(awk -F ',' '{print $2}' <<<"$input_line")
       "${script_dir}/login_with_user" "$username" "$password"
     fi
+  fi
 done <"$user_list"