Fix GH-24171: Slow stream_socket_client() connect on Windows

On Windows, php_network_connect_socket() calls getsockopt(SO_ERROR)
right after select() reports that the non-blocking connect completed.
Inside mswsock, SockIsSocketConnected() can then race with mswsock's
own async thread and wait on an internal completion port with a 10 ms
timeout, so the call often blocks for 10-25 ms.

Winsock reports a successful non-blocking connect in writefds and a
failed one in exceptfds, and we already poll for POLLOUT|POLLPRI. So
when only POLLOUT is set, the connect has succeeded and getsockopt()
can be skipped.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

Author: vibbow

NEWS

@@ -105,6 +105,9 @@ PHP                                                                        NEWS
 - Streams:
   . Applied the so_linger, so_rcvbuf and so_sndbuf context options to unix
     sockets. (David Carlier)
+  . Improved performance of stream_socket_client() and fsockopen() connects
+    on Windows by avoiding a slow getsockopt(SO_ERROR) call on success
+    (GH-24171). (vibbow)
 
 - Standard:
   . Fixed bug #60110 (fclose(), file_put_contents(), copy() do not return false

main/network.c

@@ -412,6 +412,13 @@ PHPAPI int php_network_connect_socket(php_socket_t sockfd,
 			ret = -1;
 		} else if (n == 0) {
 			error = PHP_TIMEOUT_ERROR_VALUE;
+#ifdef PHP_WIN32
+		} else if ((n & POLLOUT) && !(n & POLLPRI)) {
+			/* Writable and not in exceptfds: the connect succeeded (see the
+			 * comment above). Skip getsockopt(SO_ERROR) here, as calling it
+			 * right after the connection completes can block for 10-25ms. */
+			error = 0;
+#endif
 		} else {
 			len = sizeof(error);
 			/* BSD-derived systems set errno correctly.