Hooks::dispatch(): modernize dynamic function call

... by replacing the `call_user_func_array()` with a variable function call in combination with the spread operator.

Includes adding a dedicated test to safeguard that this change does not break the handling of references when passed as part of the `$parameters` to dispatch.

src/Hooks.php

@@ -88,7 +88,7 @@ public function dispatch($hook, $parameters = array()) {
 
 		foreach ($this->hooks[$hook] as $priority => $hooked) {
 			foreach ($hooked as $callback) {
-				call_user_func_array($callback, $parameters);
+				$callback(...$parameters);
 			}
 		}
 

tests/HooksTest.php

@@ -202,6 +202,29 @@ public function testDispatchWithMultipleRegisteredHooks() {
 		$this->assertTrue($this->hooks->dispatch('hook_b', array(10, 'text')));
 	}
 
+	/**
+	 * Technical test to verify that the dispatch method handles parameters passed by reference correctly.
+	 *
+	 * @covers ::dispatch
+	 *
+	 * @return void
+	 */
+	public function testDispatchHandlesParametersPassedByReference() {
+		$this->hooks->register('hookname', array($this, 'dummyCallbackExpectingReferences'));
+		$url             = 'original';
+		$headers         = array('original');
+		$unchanged       = 'original';
+		$not_a_reference = 'original';
+
+		$this->assertTrue($this->hooks->dispatch('hookname', array(&$url, &$headers, &$unchanged, $not_a_reference)));
+
+		// Verify that the variables were updated by reference (when passed as reference).
+		$this->assertSame('changed', $url);
+		$this->assertSame(array('changed'), $headers);
+		$this->assertSame('original', $unchanged);
+		$this->assertSame('original', $not_a_reference);
+	}
+
 	/**
 	 * Technical test to verify that the dispatch method doesn't break on PHP 8.0 when passed an associative array.
 	 *
@@ -374,4 +397,15 @@ public function dummyCallback1() {}
 	 * @return void
 	 */
 	public function dummyCallback2() {}
+
+	/**
+	 * Dummy callback method.
+	 *
+	 * @return void
+	 */
+	public function dummyCallbackExpectingReferences(&$url, &$headers, &$unchanged, $not_a_reference) {
+		$url             = 'changed';
+		$headers         = array('changed');
+		$not_a_reference = 'changed';
+	}
 }