Added regression test

Author: staabm

tests/PHPStan/Rules/Arrays/NonexistentOffsetInArrayDimFetchRuleTest.php

@@ -1106,6 +1106,13 @@ public function testPR4385Bis(): void
 		$this->analyse([__DIR__ . '/data/pr-4385-bis.php'], []);
 	}
 
+	public function testBug11276(): void
+	{
+		$this->reportPossiblyNonexistentGeneralArrayOffset = true;
+
+		$this->analyse([__DIR__ . '/data/bug-11276.php'], []);
+	}
+
 	public function testBug12805(): void
 	{
 		$this->reportPossiblyNonexistentGeneralArrayOffset = true;

tests/PHPStan/Rules/Arrays/data/bug-11276.php

@@ -0,0 +1,20 @@
+<?php
+
+namespace Bug11276;
+
+class HelloWorld
+{
+	/**
+	 * @param array{from: string, to: string} $expected
+	 */
+	public function testLanguagesMatchingRegex(string $url, ?array $expected): void
+	{
+		preg_match('#\/(?<from>[a-z]{2})-(?<to>[a-z]{1}[a-z0-9]{1})\/#', $url, $matches);
+
+		foreach ($expected as $key => $value) {
+			if ($matches instanceof ArrayAccess || \array_key_exists($key, $matches)) {
+				$matches[$key];
+			}
+		}
+	}
+}