From cabc98fbadbe9ed9a72f5e9e18c7631b4217946b Mon Sep 17 00:00:00 2001
From: dklawren <dklawren@users.noreply.github.com>
Date: Mon, 25 May 2020 16:52:20 -0400
Subject: [PATCH] Bug 1639903 - Fix `Use of uninitialized value in pattern
 match (m//) at /app/Bugzilla/App.pm line 71`

---
 Bugzilla/App.pm | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/Bugzilla/App.pm b/Bugzilla/App.pm
index 1e3e34108..003e7494c 100644
--- a/Bugzilla/App.pm
+++ b/Bugzilla/App.pm
@@ -68,7 +68,8 @@ sub startup {
       # If that is the case, we just log the error and continue on.
       try {
         my $regexp = Bugzilla->params->{block_user_agent};
-        if ($regexp && $c->req->headers->user_agent =~ /$regexp/) {
+        my $user_agent = $c->req->headers->user_agent // '';
+        if ($regexp && $user_agent =~ /$regexp/) {
           my $msg = "Contact " . Bugzilla->params->{maintainer};
           $c->respond_to(
             json => {json => {error => $msg}, status => 400},
-- 
2.47.3