From f2294a709a7d683fb95fa94ce427384a3d97e60b Mon Sep 17 00:00:00 2001
From: Yorhel <git@yorhel.nl>
Date: Sun, 20 Apr 2025 11:31:15 +0200
Subject: [PATCH] FU: Fix warning when calling fu->set_header() with undef
 value

---
 FU.pm | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/FU.pm b/FU.pm
index c21bb7f..37f90db 100644
--- a/FU.pm
+++ b/FU.pm
@@ -728,7 +728,7 @@ sub reset {
 
 sub _validate_header($hdr, $val) {
     confess "Invalid response header '$hdr'" if $hdr !~ /^$FU::hdrname_re$/;
-    confess "Invalid attempt to set response header containing a newline" if $val =~ /[\r\n]/;
+    confess "Invalid attempt to set response header containing a newline" if defined $val && $val =~ /[\r\n]/;
 }
 
 sub add_header($, $hdr, $val) {