Add get_headers stub (#5140)

Author: VincentLanglet

stubs/core.stub

@@ -389,6 +389,11 @@ function abs($num) {}
  */
 function get_defined_constants(bool $categorize = false): array {}
 
+/**
+ * @return ($associative is false ? list<string>|false : array<int|string, string|list<string>>|false)
+ */
+function get_headers(string $url, bool $associative = false, ?resource $context = null): array|false {}
+
 /**
  * @param array<string> $long_options
  * @param mixed $rest_index

tests/PHPStan/Analyser/nsrt/get_headers.php

@@ -0,0 +1,9 @@
+<?php declare(strict_types = 1);
+
+namespace Bug13835;
+
+use function PHPStan\Testing\assertType;
+
+assertType('list<string>|false', get_headers('http://example.com'));
+assertType('array<int|string, list<string>|string>|false', get_headers('http://example.com', true));
+assertType('list<string>|false', get_headers('http://example.com', false));