Added regression test

Author: staabm

tests/PHPStan/Rules/Variables/ParameterOutAssignedTypeRuleTest.php

@@ -74,4 +74,9 @@ public function testBug13093b(): void
 		$this->analyse([__DIR__ . '/data/bug-13093b.php'], []);
 	}
 
+	public function testBug12754(): void
+	{
+		$this->analyse([__DIR__ . '/data/bug-12754.php'], []);
+	}
+
 }

tests/PHPStan/Rules/Variables/data/bug-12330.php

@@ -17,7 +17,7 @@ function alterItems(array &$options): void
  * @param array{items: array<int, array<string, mixed>>} $options
  * @param-out array{items: array<int, array<string, mixed>>} $options
  */
-function alterItems(array &$options): void
+function alterItems2(array &$options): void
 {
 	foreach ($options['items'] as $i => $item) {
 		$options['items'][$i]['options']['title'] = $item['name'];

tests/PHPStan/Rules/Variables/data/bug-12754.php

@@ -0,0 +1,26 @@
+<?php
+
+namespace Bug12754;
+
+class HelloWorld
+{
+	/**
+	 * @param list<array{string, string}> $list
+	 * @return void
+	 */
+	public function modify(array &$list): void
+	{
+		foreach ($list as $int => $array) {
+			$list[$int][1] = $this->apply($array[1]);
+		}
+	}
+
+	/**
+	 * @param string $value
+	 * @return string
+	 */
+	public function apply(string $value): mixed
+	{
+		return $value;
+	}
+}