From cbe2ba55cefe58b5372452bca32b8ecfc9b3fe7e Mon Sep 17 00:00:00 2001
From: Fehler12 <53938045+Fehler12@users.noreply.github.com>
Date: Mon, 21 Aug 2023 00:17:25 +0200
Subject: [PATCH] Added empty string check (#15235)

* Added empty string check

* replaced tabs with spaces

replaced tabs with spaces

* Removed '(', ')' and enlarged if clause

* Added one space and removed an empty row

* removed is_null

Removed is_null check as static code analysis says that this variable cannot be null at this time

* compact form

* handle spaces

In case the sysName is " " (one space). Good to trim anyway.

---------

Co-authored-by: PipoCanaja <38363551+PipoCanaja@users.noreply.github.com>
---
 app/Models/Device.php | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/app/Models/Device.php b/app/Models/Device.php
index 20479b5778..e640a57ef0 100644
--- a/app/Models/Device.php
+++ b/app/Models/Device.php
@@ -180,12 +180,15 @@ class Device extends BaseModel
     {
         $hostname_is_ip = IP::isValid($this->hostname);
 
-        return SimpleTemplate::parse($this->display ?: \LibreNMS\Config::get('device_display_default', '{{ $hostname }}'), [
+        $return_value = SimpleTemplate::parse($this->display ?: \LibreNMS\Config::get('device_display_default', '{{ $hostname }}'), [
             'hostname' => $this->hostname,
             'sysName' => $this->sysName ?: $this->hostname,
             'sysName_fallback' => $hostname_is_ip ? $this->sysName : $this->hostname,
             'ip' => $this->overwrite_ip ?: ($hostname_is_ip ? $this->hostname : $this->ip),
         ]);
+
+        // in case the displayName is a string without any content, return hostname
+        return trim($return_value) ?: $this->hostname;
     }
 
     /**