Deprecate AI_IDN_ALLOW_UNASSIGNED and AI_IDN_USE_STD3_ASCII_RULES

These flags have been deprecated in glibc 2.28, so we also
deprecate them in PHP.

As we can't deprecate constants, we can only check for their use
in socket_addrinfo_lookup().

Author: viest

UPGRADING

@@ -404,6 +404,11 @@ PHP 7.4 UPGRADE NOTES
         // $str = ReflectionClass::export(Foo::class, true) is:
         $str = (string) new ReflectionClass(Foo::class);
 
+- Socket:
+  . The AI_IDN_ALLOW_UNASSIGNED and AI_IDN_USE_STD3_ASCII_RULES flags for
+    socket_addrinfo_lookup() are deprecated, due to an upstream deprecation in
+    glibc.
+
 - Standard:
   . Passing invalid characters to ''base_convert()'', ''bindec()'', ''octdec()''
     and ''hexdec()'' will now generate a deprecation notice. The result will

ext/sockets/sockets.c

@@ -2573,7 +2573,14 @@ PHP_FUNCTION(socket_addrinfo_lookup)
 		ZEND_HASH_FOREACH_STR_KEY_VAL(Z_ARRVAL_P(zhints), key, hint) {
 			if (key) {
 				if (zend_string_equals_literal(key, "ai_flags")) {
-					hints.ai_flags = zval_get_long(hint);
+					zend_long flags = zval_get_long(hint);
+#if HAVE_AI_IDN
+					if (flags & (AI_IDN_ALLOW_UNASSIGNED | AI_IDN_USE_STD3_ASCII_RULES)) {
+						php_error_docref(NULL, E_DEPRECATED,
+							"AI_IDN_ALLOW_UNASSIGNED and AI_IDN_USE_STD3_ASCII_RULES are deprecated");
+					}
+#endif
+					hints.ai_flags = flags;
 				} else if (zend_string_equals_literal(key, "ai_socktype")) {
 					hints.ai_socktype = zval_get_long(hint);
 				} else if (zend_string_equals_literal(key, "ai_protocol")) {

ext/sockets/tests/ai_idn_deprecation.phpt

@@ -0,0 +1,20 @@
+--TEST--
+AI_IDN_ALLOW_UNASSIGNED and AI_IDN_USE_STD3_ASCII_RULES are deprecated
+--SKIPIF--
+<?php
+if (!extension_loaded('sockets')) die('skip The sockets extension is not loaded');
+if (!defined('AI_IDN_ALLOW_UNASSIGNED')) die('skip AI_IDN_ALLOW_UNASSIGNED not defined');
+?>
+--FILE--
+<?php
+$addrinfo = socket_addrinfo_lookup('127.0.0.1', 2000, array(
+    'ai_family' => AF_INET,
+    'ai_socktype' => SOCK_DGRAM,
+    'ai_flags' => AI_IDN_ALLOW_UNASSIGNED,
+));
+var_dump(socket_addrinfo_connect($addrinfo[0]));
+echo "Done";
+--EXPECTF--
+Deprecated: socket_addrinfo_lookup(): AI_IDN_ALLOW_UNASSIGNED and AI_IDN_USE_STD3_ASCII_RULES are deprecated in %s on line %d
+resource(%d) of type (Socket)
+Done