Fix poll event leak on negative stream timeout

Add test and changelog entry for the negative timeout overflow fix
in network_async.c where tv_sec < 0 caused poll event refcount leak.

Author: EdmondDantes

CHANGELOG.md

@@ -5,11 +5,12 @@ All notable changes to the Async extension for PHP will be documented in this fi
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
-## [0.6.3] - 2026-03-24
+## [0.6.3] - 2026-03-25
 
 ### Fixed
 - **`Scope::awaitCompletion()` ignoring completion**: `async_scope_notify_coroutine_finished()` was missing the call to `scope_check_completion_and_notify()`, so `awaitCompletion()` never woke up when all coroutines finished and always waited until the timeout expired.
 - **`Scope::awaitAfterCancellation()` cleanup**: Replaced `zend_async_waker_clean()` with `ZEND_ASYNC_WAKER_DESTROY()` on error paths, and switched to checking the return value of `zend_async_resume_when()` instead of `EG(exception)`.
+- **Negative stream timeout causing poll event leak**: When a stream context timeout was negative (e.g. `PHP_INT_MIN`), the signed `tv_sec` overflowed to a huge positive value when cast to `zend_ulong` milliseconds. This created an async waker with a timer event that held an extra reference to the poll event (refcount 3 instead of 2), causing it to leak. Fixed by checking `tv_sec < 0` before the conversion and falling back to synchronous `php_pollfd_for()`.
 
 ## [0.6.2] - 2026-03-24
 

tests/io/082-http_negative_timeout_poll_leak.phpt

@@ -0,0 +1,33 @@
+--TEST--
+GH-16809 (fopen HTTP wrapper timeout stream context option overflow)
+--INI--
+allow_url_fopen=1
+--SKIPIF--
+<?php if (PHP_INT_SIZE != 8) die("skip this test is for 64bit platform only"); ?>
+--FILE--
+<?php
+$serverCode = <<<'CODE'
+echo 1;
+CODE;
+
+include __DIR__."/../../../../sapi/cli/tests/php_cli_server.inc";
+php_cli_server_start($serverCode, null, []);
+
+$uri = "http://" . PHP_CLI_SERVER_ADDRESS . '/test';
+$config = [
+    'http' => [
+        'timeout' => PHP_INT_MIN,
+    ],
+];
+$ctx = stream_context_create($config);
+var_dump(fopen($uri, "r", false, $ctx));
+
+$config['http']['timeout'] = PHP_INT_MAX;
+$ctx = stream_context_create($config);
+var_dump(fopen($uri, "r", false, $ctx));
+?>
+--EXPECTF--
+resource(%d) of type (stream)
+
+Warning: fopen(http://%s): Failed to open stream: timeout must be lower than %d in %s on line %d
+bool(false)