[BUGFIX] Use unknown OS icon instead of Windows as fallback

Resolves: #84870
Releases: master, 8.7
Change-Id: Ia89f4ba0aa70616e185cad6cc29858157ef0e656
Reviewed-on: https://review.typo3.org/57362
Tested-by: TYPO3com <no-reply@typo3.com>
Reviewed-by: Anja Leichsenring <aleichsenring@ab-softlab.de>
Tested-by: Anja Leichsenring <aleichsenring@ab-softlab.de>
Reviewed-by: Mathias Brodala <mbrodala@pagemachine.de>
Tested-by: Mathias Brodala <mbrodala@pagemachine.de>

typo3/sysext/backend/Classes/Backend/ToolbarItems/SystemInformationToolbarItem.php

@@ -208,16 +208,19 @@ protected function getGitRevision()
      */
     protected function getOperatingSystem()
     {
-        $kernelName = php_uname('s');
+        $kernelName = PHP_OS;
         switch (strtolower($kernelName)) {
             case 'linux':
                 $icon = 'linux';
                 break;
             case 'darwin':
                 $icon = 'apple';
                 break;
-            default:
+            case StringUtility::beginsWith($kernelName, 'win'):
                 $icon = 'windows';
+                break;
+            default:
+                $icon = 'unknown';
         }
         $this->systemInformation[] = [
             'title' => 'LLL:EXT:lang/Resources/Private/Language/locallang_core.xlf:toolbarItems.sysinfo.operatingsystem',

typo3/sysext/core/Classes/Imaging/IconRegistry.php

@@ -2971,6 +2971,12 @@ class IconRegistry implements SingletonInterface
                 'name' => 'windows'
             ]
         ],
+        'sysinfo-os-unknown' => [
+            'provider' => SvgIconProvider::class,
+            'options' => [
+                'source' => 'EXT:core/Resources/Public/Icons/T3Icons/sysinfo/sysinfo-os-unknown.svg'
+            ]
+        ],
         'sysinfo-typo3-version' => [
             'provider' => SvgIconProvider::class,
             'options' => [