Return value of mb_get_info can be NULL

This has been the case at least since PHP 5.4. Thanks to Girgias for
pointing it out.

It appears that there are several global variables internal to mbstring
which can be queried via mb_get_info() and which could be NULL, but
at the very least, we know that "mbstring.http_input" is one of them.

Author: alexdowad

Zend/Optimizer/zend_func_infos.h

@@ -235,7 +235,7 @@ static const func_info_t func_infos[] = {
 	F1("mb_convert_variables", MAY_BE_STRING|MAY_BE_FALSE),
 	F1("mb_encode_numericentity", MAY_BE_STRING),
 	F1("mb_decode_numericentity", MAY_BE_STRING),
-	F1("mb_get_info", MAY_BE_ARRAY|MAY_BE_ARRAY_KEY_LONG|MAY_BE_ARRAY_KEY_STRING|MAY_BE_ARRAY_OF_LONG|MAY_BE_ARRAY_OF_STRING|MAY_BE_ARRAY_OF_ARRAY|MAY_BE_STRING|MAY_BE_LONG|MAY_BE_FALSE),
+	F1("mb_get_info", MAY_BE_ARRAY|MAY_BE_ARRAY_KEY_LONG|MAY_BE_ARRAY_KEY_STRING|MAY_BE_ARRAY_OF_LONG|MAY_BE_ARRAY_OF_STRING|MAY_BE_ARRAY_OF_ARRAY|MAY_BE_STRING|MAY_BE_LONG|MAY_BE_FALSE|MAY_BE_NULL),
 #if defined(HAVE_MBREGEX)
 	F1("mb_regex_encoding", MAY_BE_STRING|MAY_BE_BOOL),
 #endif

ext/mbstring/mbstring.stub.php

@@ -171,10 +171,10 @@ function mb_decode_numericentity(string $string, array $map, ?string $encoding =
 function mb_send_mail(string $to, string $subject, string $message, array|string $additional_headers = [], ?string $additional_params = null): bool {}
 
 /**
- * @return array<int|string, int|string|array>|string|int|false
+ * @return array<int|string, int|string|array>|string|int|false|null
  * @refcount 1
  */
-function mb_get_info(string $type = "all"): array|string|int|false {}
+function mb_get_info(string $type = "all"): array|string|int|false|null {}
 
 function mb_check_encoding(array|string|null $value = null, ?string $encoding = null): bool {}
 

ext/mbstring/mbstring_arginfo.h

@@ -0,0 +1,10 @@
+--TEST--
+mb_get_info("http_input") can return null
+--EXTENSIONS--
+mbstring
+--FILE--
+<?php
+var_dump(mb_get_info("http_input"));
+?>
+--EXPECT--
+NULL