PHP 8 ready.

.scrutinizer.yml

@@ -5,6 +5,10 @@ filter:
     - 'test/'
 
 build:
+  environment:
+    php:
+      version: '7.4'
+
   nodes:
     analysis:
       tests:

.travis.yml

@@ -1,7 +1,7 @@
 language: php
 php:
-  - '7.3'
   - '7.4'
+  - '8.0'
 
 install:
   - composer self-update

src/Url.php

@@ -100,7 +100,7 @@ public static function combine(string $uri1, string $uri2): string
     }
 
     // Handle spacial cases for the fragment part of the URI.
-    if (!isset($parts2['fragment']))
+    if (($parts2['fragment'] ?? '')==='')
     {
       $combined_uri_parts['fragment'] = null;
     }