Fix UNKNOWN default values in various extensions

Closes GH-5514

25 files changed, 109 insertions, 112 deletions

diff --git a/Zend/zend_API.h b/Zend/zend_API.h
index 0e361ad7c5..f97f54af44 100644
--- a/Zend/zend_API.h
+++ b/Zend/zend_API.h
@@ -1327,6 +1327,9 @@ ZEND_API ZEND_COLD void ZEND_FASTCALL zend_argument_value_error(uint32_t arg_num
 #define Z_PARAM_BOOL(dest) \
 	Z_PARAM_BOOL_EX(dest, _dummy, 0, 0)
 
+#define Z_PARAM_BOOL_OR_NULL(dest, is_null) \
+	Z_PARAM_BOOL_EX(dest, is_null, 1, 0)
+
 /* old "C" */
 #define Z_PARAM_CLASS_EX2(dest, check_null, deref, separate) \
 		Z_PARAM_PROLOGUE(deref, separate); \
@@ -1558,6 +1561,9 @@ ZEND_API ZEND_COLD void ZEND_FASTCALL zend_argument_value_error(uint32_t arg_num
 #define Z_PARAM_STR(dest) \
 	Z_PARAM_STR_EX(dest, 0, 0)
 
+#define Z_PARAM_STR_OR_NULL(dest) \
+	Z_PARAM_STR_EX(dest, 1, 0)
+
 /* old "z" */
 #define Z_PARAM_ZVAL_EX2(dest, check_null, deref, separate) \
 		Z_PARAM_PROLOGUE(deref, separate); \
diff --git a/ext/dom/php_dom.stub.php b/ext/dom/php_dom.stub.php
index 8f1b375471..3d77b136c7 100644
--- a/ext/dom/php_dom.stub.php
+++ b/ext/dom/php_dom.stub.php
@@ -103,11 +103,10 @@ class DOMImplementation
     public function hasFeature(string $feature, string $version) {}
 
     /** @return DOMDocumentType|false */
-    public function createDocumentType(
-        string $qualifiedName, string $publicId = "", string $systemId = "") {}
+    public function createDocumentType(string $qualifiedName, string $publicId = "", string $systemId = "") {}
 
     /** @return DOMDocument|false */
-    public function createDocument(string $namespaceURI = "", string $qualifiedName = "", DOMDocumentType $doctype = UNKNOWN) {}
+    public function createDocument(string $namespaceURI = "", string $qualifiedName = "", ?DOMDocumentType $doctype = null) {}
 }
 
 class DOMDocumentFragment implements DOMParentNode
@@ -248,7 +247,7 @@ class DOMElement implements DOMParentNode, DOMChildNode
 
 class DOMDocument implements DOMParentNode
 {
-    public function __construct(string $version = "1.0", string $encoding = UNKNOWN) {}
+    public function __construct(string $version = "1.0", string $encoding = "") {}
 
     /** @return DOMAttr|false */
     public function createAttribute(string $name) {}
diff --git a/ext/dom/php_dom_arginfo.h b/ext/dom/php_dom_arginfo.h
index e989301311..c7fd0c81df 100644
--- a/ext/dom/php_dom_arginfo.h
+++ b/ext/dom/php_dom_arginfo.h
@@ -107,7 +107,7 @@ ZEND_END_ARG_INFO()
 ZEND_BEGIN_ARG_INFO_EX(arginfo_class_DOMImplementation_createDocument, 0, 0, 0)
 	ZEND_ARG_TYPE_INFO_WITH_DEFAULT_VALUE(0, namespaceURI, IS_STRING, 0, "\"\"")
 	ZEND_ARG_TYPE_INFO_WITH_DEFAULT_VALUE(0, qualifiedName, IS_STRING, 0, "\"\"")
-	ZEND_ARG_OBJ_INFO(0, doctype, DOMDocumentType, 0)
+	ZEND_ARG_OBJ_INFO_WITH_DEFAULT_VALUE(0, doctype, DOMDocumentType, 1, "null")
 ZEND_END_ARG_INFO()
 
 #define arginfo_class_DOMDocumentFragment___construct arginfo_class_DOMNode_getLineNo
@@ -244,7 +244,7 @@ ZEND_END_ARG_INFO()
 
 ZEND_BEGIN_ARG_INFO_EX(arginfo_class_DOMDocument___construct, 0, 0, 0)
 	ZEND_ARG_TYPE_INFO_WITH_DEFAULT_VALUE(0, version, IS_STRING, 0, "\"1.0\"")
-	ZEND_ARG_TYPE_INFO(0, encoding, IS_STRING, 0)
+	ZEND_ARG_TYPE_INFO_WITH_DEFAULT_VALUE(0, encoding, IS_STRING, 0, "\"\"")
 ZEND_END_ARG_INFO()
 
 #define arginfo_class_DOMDocument_createAttribute arginfo_class_DOMElement_getAttribute
diff --git a/ext/enchant/enchant.c b/ext/enchant/enchant.c
index 0195555379..1c43323f95 100644
--- a/ext/enchant/enchant.c
+++ b/ext/enchant/enchant.c
@@ -656,9 +656,9 @@ PHP_FUNCTION(enchant_dict_quick_check)
 			enchant_dict_free_string_list(pdict->pdict, suggs);
 		}
 
-
 		RETURN_FALSE;
 	}
+
 	RETURN_TRUE;
 }
 /* }}} */
diff --git a/ext/enchant/enchant.stub.php b/ext/enchant/enchant.stub.php
index cad28b9103..f235ff59ba 100644
--- a/ext/enchant/enchant.stub.php
+++ b/ext/enchant/enchant.stub.php
@@ -54,7 +54,7 @@ function enchant_broker_set_ordering($broker, string $tag, string $ordering): bo
 function enchant_broker_describe($broker): array {}
 
 /** @param resource $dict */
-function enchant_dict_quick_check($dict, string $word, &$suggestions = UNKNOWN): bool {}
+function enchant_dict_quick_check($dict, string $word, &$suggestions = null): bool {}
 
 /** @param resource $dict */
 function enchant_dict_check($dict, string $word): bool {}
diff --git a/ext/enchant/enchant_arginfo.h b/ext/enchant/enchant_arginfo.h
index 967bdfcf72..b0906d9a3d 100644
--- a/ext/enchant/enchant_arginfo.h
+++ b/ext/enchant/enchant_arginfo.h
@@ -56,7 +56,7 @@ ZEND_END_ARG_INFO()
 ZEND_BEGIN_ARG_WITH_RETURN_TYPE_INFO_EX(arginfo_enchant_dict_quick_check, 0, 2, _IS_BOOL, 0)
 	ZEND_ARG_INFO(0, dict)
 	ZEND_ARG_TYPE_INFO(0, word, IS_STRING, 0)
-	ZEND_ARG_INFO(1, suggestions)
+	ZEND_ARG_INFO_WITH_DEFAULT_VALUE(1, suggestions, "null")
 ZEND_END_ARG_INFO()
 
 ZEND_BEGIN_ARG_WITH_RETURN_TYPE_INFO_EX(arginfo_enchant_dict_check, 0, 2, _IS_BOOL, 0)
diff --git a/ext/ffi/ffi.c b/ext/ffi/ffi.c
index 1ca8a9be75..7784c7b389 100644
--- a/ext/ffi/ffi.c
+++ b/ext/ffi/ffi.c
@@ -2835,7 +2835,7 @@ ZEND_METHOD(FFI, cdef) /* {{{ */
 	ZEND_PARSE_PARAMETERS_START(0, 2)
 		Z_PARAM_OPTIONAL
 		Z_PARAM_STR(code)
-		Z_PARAM_STR(lib)
+		Z_PARAM_STR_OR_NULL(lib)
 	ZEND_PARSE_PARAMETERS_END();
 
 	if (lib) {
@@ -2854,7 +2854,7 @@ ZEND_METHOD(FFI, cdef) /* {{{ */
 	FFI_G(symbols) = NULL;
 	FFI_G(tags) = NULL;
 
-	if (code) {
+	if (code && ZSTR_LEN(code)) {
 		/* Parse C definitions */
 		FFI_G(default_type_attr) = ZEND_FFI_ATTR_STORED;
 
diff --git a/ext/ffi/ffi.stub.php b/ext/ffi/ffi.stub.php
index a45235469e..89d1890e61 100644
--- a/ext/ffi/ffi.stub.php
+++ b/ext/ffi/ffi.stub.php
@@ -4,7 +4,7 @@
 
 final class FFI
 {
-    public static function cdef(string $code = UNKNOWN, string $lib = UNKNOWN): FFI {}
+    public static function cdef(string $code = "", ?string $lib = null): FFI {}
 
     public static function load(string $filename): ?FFI {}
 
diff --git a/ext/ffi/ffi_arginfo.h b/ext/ffi/ffi_arginfo.h
index 009512fe82..8bd12b0998 100644
--- a/ext/ffi/ffi_arginfo.h
+++ b/ext/ffi/ffi_arginfo.h
@@ -1,8 +1,8 @@
 /* This is a generated file, edit the .stub.php file instead. */
 
 ZEND_BEGIN_ARG_WITH_RETURN_OBJ_INFO_EX(arginfo_class_FFI_cdef, 0, 0, FFI, 0)
-	ZEND_ARG_TYPE_INFO(0, code, IS_STRING, 0)
-	ZEND_ARG_TYPE_INFO(0, lib, IS_STRING, 0)
+	ZEND_ARG_TYPE_INFO_WITH_DEFAULT_VALUE(0, code, IS_STRING, 0, "\"\"")
+	ZEND_ARG_TYPE_INFO_WITH_DEFAULT_VALUE(0, lib, IS_STRING, 1, "null")
 ZEND_END_ARG_INFO()
 
 ZEND_BEGIN_ARG_WITH_RETURN_OBJ_INFO_EX(arginfo_class_FFI_load, 0, 1, FFI, 1)
diff --git a/ext/ftp/ftp.stub.php b/ext/ftp/ftp.stub.php
index 72b7126843..b293c453fa 100644
--- a/ext/ftp/ftp.stub.php
+++ b/ext/ftp/ftp.stub.php
@@ -38,7 +38,7 @@ function ftp_rmdir($ftp, string $directory): bool {}
 function ftp_chmod($ftp, int $mode, string $filename): int|false {}
 
 /** @param resource $ftp */
-function ftp_alloc($ftp, int $size, &$response = UNKNOWN): bool {}
+function ftp_alloc($ftp, int $size, &$response = null): bool {}
 
 /** @param resource $ftp */
 function ftp_nlist($ftp, string $directory): array|false {}
diff --git a/ext/ftp/ftp_arginfo.h b/ext/ftp/ftp_arginfo.h
index 83e7b672f4..738f8e9284 100644
--- a/ext/ftp/ftp_arginfo.h
+++ b/ext/ftp/ftp_arginfo.h
@@ -59,7 +59,7 @@ ZEND_END_ARG_INFO()
 ZEND_BEGIN_ARG_WITH_RETURN_TYPE_INFO_EX(arginfo_ftp_alloc, 0, 2, _IS_BOOL, 0)
 	ZEND_ARG_INFO(0, ftp)
 	ZEND_ARG_TYPE_INFO(0, size, IS_LONG, 0)
-	ZEND_ARG_INFO(1, response)
+	ZEND_ARG_INFO_WITH_DEFAULT_VALUE(1, response, "null")
 ZEND_END_ARG_INFO()
 
 ZEND_BEGIN_ARG_WITH_RETURN_TYPE_MASK_EX(arginfo_ftp_nlist, 0, 2, MAY_BE_ARRAY|MAY_BE_FALSE)
diff --git a/ext/hash/hash.c b/ext/hash/hash.c
index 25c816d47a..31ead37163 100644
--- a/ext/hash/hash.c
+++ b/ext/hash/hash.c
@@ -481,13 +481,13 @@ PHP_FUNCTION(hash_update_file)
 {
 	zval *zhash, *zcontext = NULL;
 	php_hashcontext_object *hash;
-	php_stream_context *context;
+	php_stream_context *context = NULL;
 	php_stream *stream;
 	zend_string *filename;
 	char buf[1024];
 	ssize_t n;
 
-	if (zend_parse_parameters(ZEND_NUM_ARGS(), "OP|r", &zhash, php_hashcontext_ce, &filename, &zcontext) == FAILURE) {
+	if (zend_parse_parameters(ZEND_NUM_ARGS(), "OP|r!", &zhash, php_hashcontext_ce, &filename, &zcontext) == FAILURE) {
 		RETURN_THROWS();
 	}
 
diff --git a/ext/hash/hash.stub.php b/ext/hash/hash.stub.php
index e83f38b22c..a634112d00 100644
--- a/ext/hash/hash.stub.php
+++ b/ext/hash/hash.stub.php
@@ -10,7 +10,7 @@ function hash_hmac(string $algo, string $data, string $key, bool $raw_output = f
 
 function hash_hmac_file(string $algo, string $data, string $key, bool $raw_output = false): string|false {}
 
-function hash_init(string $algo, int $options = 0, string $key = UNKNOWN): HashContext {}
+function hash_init(string $algo, int $options = 0, string $key = ""): HashContext {}
 
 function hash_update(HashContext $context, string $data): bool {}
 
@@ -18,7 +18,7 @@ function hash_update(HashContext $context, string $data): bool {}
 function hash_update_stream(HashContext $context, $handle, int $length = -1): int {}
 
 /** @param resource $stream_context */
-function hash_update_file(HashContext $context, string $filename, $stream_context = UNKNOWN): bool {}
+function hash_update_file(HashContext $context, string $filename, $stream_context = null): bool {}
 
 function hash_final(HashContext $context, bool $raw_output = false): string {}
 
diff --git a/ext/hash/hash_arginfo.h b/ext/hash/hash_arginfo.h
index 156c7ad2d2..13e95aa030 100644
--- a/ext/hash/hash_arginfo.h
+++ b/ext/hash/hash_arginfo.h
@@ -24,7 +24,7 @@ ZEND_END_ARG_INFO()
 ZEND_BEGIN_ARG_WITH_RETURN_OBJ_INFO_EX(arginfo_hash_init, 0, 1, HashContext, 0)
 	ZEND_ARG_TYPE_INFO(0, algo, IS_STRING, 0)
 	ZEND_ARG_TYPE_INFO_WITH_DEFAULT_VALUE(0, options, IS_LONG, 0, "0")
-	ZEND_ARG_TYPE_INFO(0, key, IS_STRING, 0)
+	ZEND_ARG_TYPE_INFO_WITH_DEFAULT_VALUE(0, key, IS_STRING, 0, "\"\"")
 ZEND_END_ARG_INFO()
 
 ZEND_BEGIN_ARG_WITH_RETURN_TYPE_INFO_EX(arginfo_hash_update, 0, 2, _IS_BOOL, 0)
@@ -41,7 +41,7 @@ ZEND_END_ARG_INFO()
 ZEND_BEGIN_ARG_WITH_RETURN_TYPE_INFO_EX(arginfo_hash_update_file, 0, 2, _IS_BOOL, 0)
 	ZEND_ARG_OBJ_INFO(0, context, HashContext, 0)
 	ZEND_ARG_TYPE_INFO(0, filename, IS_STRING, 0)
-	ZEND_ARG_INFO(0, stream_context)
+	ZEND_ARG_INFO_WITH_DEFAULT_VALUE(0, stream_context, "null")
 ZEND_END_ARG_INFO()
 
 ZEND_BEGIN_ARG_WITH_RETURN_TYPE_INFO_EX(arginfo_hash_final, 0, 1, IS_STRING, 0)
diff --git a/ext/iconv/iconv.c b/ext/iconv/iconv.c
index 7cda884a65..ad427eaf3a 100644
--- a/ext/iconv/iconv.c
+++ b/ext/iconv/iconv.c
@@ -1826,20 +1826,22 @@ static void _php_iconv_show_error(php_iconv_err_t err, const char *out_charset,
    Returns the character count of str */
 PHP_FUNCTION(iconv_strlen)
 {
-	const char *charset = get_internal_encoding();
-	size_t charset_len = 0;
+	const char *charset = NULL;
+	size_t charset_len;
 	zend_string *str;
 
 	php_iconv_err_t err;
 
 	size_t retval;
 
-	if (zend_parse_parameters(ZEND_NUM_ARGS(), "S|s",
+	if (zend_parse_parameters(ZEND_NUM_ARGS(), "S|s!",
 		&str, &charset, &charset_len) == FAILURE) {
 		RETURN_THROWS();
 	}
 
-	if (charset_len >= ICONV_CSNMAXLEN) {
+	if (charset == NULL) {
+	 	charset = get_internal_encoding();
+	} else if (charset_len >= ICONV_CSNMAXLEN) {
 		php_error_docref(NULL, E_WARNING, "Charset parameter exceeds the maximum allowed length of %d characters", ICONV_CSNMAXLEN);
 		RETURN_FALSE;
 	}
@@ -1858,8 +1860,8 @@ PHP_FUNCTION(iconv_strlen)
    Returns specified part of a string */
 PHP_FUNCTION(iconv_substr)
 {
-	const char *charset = get_internal_encoding();
-	size_t charset_len = 0;
+	const char *charset = NULL;
+	size_t charset_len;
 	zend_string *str;
 	zend_long offset, length = 0;
 	zend_bool len_is_null = 1;
@@ -1868,13 +1870,15 @@ PHP_FUNCTION(iconv_substr)
 
 	smart_str retval = {0};
 
-	if (zend_parse_parameters(ZEND_NUM_ARGS(), "Sl|l!s",
+	if (zend_parse_parameters(ZEND_NUM_ARGS(), "Sl|l!s!",
 		&str, &offset, &length, &len_is_null,
 		&charset, &charset_len) == FAILURE) {
 		RETURN_THROWS();
 	}
 
-	if (charset_len >= ICONV_CSNMAXLEN) {
+	if (charset == NULL) {
+	 	charset = get_internal_encoding();
+	} else if (charset_len >= ICONV_CSNMAXLEN) {
 		php_error_docref(NULL, E_WARNING, "Charset parameter exceeds the maximum allowed length of %d characters", ICONV_CSNMAXLEN);
 		RETURN_FALSE;
 	}
@@ -1898,8 +1902,8 @@ PHP_FUNCTION(iconv_substr)
    Finds position of first occurrence of needle within part of haystack beginning with offset */
 PHP_FUNCTION(iconv_strpos)
 {
-	const char *charset = get_internal_encoding();
-	size_t charset_len = 0, haystk_len;
+	const char *charset = NULL;
+	size_t charset_len, haystk_len;
 	zend_string *haystk;
 	zend_string *ndl;
 	zend_long offset = 0;
@@ -1908,13 +1912,15 @@ PHP_FUNCTION(iconv_strpos)
 
 	size_t retval;
 
-	if (zend_parse_parameters(ZEND_NUM_ARGS(), "SS|ls",
+	if (zend_parse_parameters(ZEND_NUM_ARGS(), "SS|ls!",
 		&haystk, &ndl,
 		&offset, &charset, &charset_len) == FAILURE) {
 		RETURN_THROWS();
 	}
 
-	if (charset_len >= ICONV_CSNMAXLEN) {
+	if (charset == NULL) {
+	 	charset = get_internal_encoding();
+	} else if (charset_len >= ICONV_CSNMAXLEN) {
 		php_error_docref(NULL, E_WARNING, "Charset parameter exceeds the maximum allowed length of %d characters", ICONV_CSNMAXLEN);
 		RETURN_FALSE;
 	}
@@ -1953,8 +1959,8 @@ PHP_FUNCTION(iconv_strpos)
    Finds position of last occurrence of needle within part of haystack beginning with offset */
 PHP_FUNCTION(iconv_strrpos)
 {
-	const char *charset = get_internal_encoding();
-	size_t charset_len = 0;
+	const char *charset = NULL;
+	size_t charset_len;
 	zend_string *haystk;
 	zend_string *ndl;
 
@@ -1962,7 +1968,7 @@ PHP_FUNCTION(iconv_strrpos)
 
 	size_t retval;
 
-	if (zend_parse_parameters(ZEND_NUM_ARGS(), "SS|s",
+	if (zend_parse_parameters(ZEND_NUM_ARGS(), "SS|s!",
 		&haystk, &ndl,
 		&charset, &charset_len) == FAILURE) {
 		RETURN_THROWS();
@@ -1972,7 +1978,9 @@ PHP_FUNCTION(iconv_strrpos)
 		RETURN_FALSE;
 	}
 
-	if (charset_len >= ICONV_CSNMAXLEN) {
+	if (charset == NULL) {
+	 	charset = get_internal_encoding();
+	} else if (charset_len >= ICONV_CSNMAXLEN) {
 		php_error_docref(NULL, E_WARNING, "Charset parameter exceeds the maximum allowed length of %d characters", ICONV_CSNMAXLEN);
 		RETURN_FALSE;
 	}
@@ -2097,21 +2105,23 @@ PHP_FUNCTION(iconv_mime_encode)
 PHP_FUNCTION(iconv_mime_decode)
 {
 	zend_string *encoded_str;
-	const char *charset = get_internal_encoding();
-	size_t charset_len = 0;
+	const char *charset = NULL;
+	size_t charset_len;
 	zend_long mode = 0;
 
 	smart_str retval = {0};
 
 	php_iconv_err_t err;
 
-	if (zend_parse_parameters(ZEND_NUM_ARGS(), "S|ls",
+	if (zend_parse_parameters(ZEND_NUM_ARGS(), "S|ls!",
 		&encoded_str, &mode, &charset, &charset_len) == FAILURE) {
 
 		RETURN_THROWS();
 	}
 
-	if (charset_len >= ICONV_CSNMAXLEN) {
+	if (charset == NULL) {
+	 	charset = get_internal_encoding();
+	} else if (charset_len >= ICONV_CSNMAXLEN) {
 		php_error_docref(NULL, E_WARNING, "Charset parameter exceeds the maximum allowed length of %d characters", ICONV_CSNMAXLEN);
 		RETURN_FALSE;
 	}
@@ -2137,21 +2147,23 @@ PHP_FUNCTION(iconv_mime_decode)
 PHP_FUNCTION(iconv_mime_decode_headers)
 {
 	zend_string *encoded_str;
-	const char *charset = get_internal_encoding();
-	size_t charset_len = 0;
+	const char *charset = NULL;
+	size_t charset_len;
 	zend_long mode = 0;
 	char *enc_str_tmp;
 	size_t enc_str_len_tmp;
 
 	php_iconv_err_t err = PHP_ICONV_ERR_SUCCESS;
 
-	if (zend_parse_parameters(ZEND_NUM_ARGS(), "S|ls",
+	if (zend_parse_parameters(ZEND_NUM_ARGS(), "S|ls!",
 		&encoded_str, &mode, &charset, &charset_len) == FAILURE) {
 
 		RETURN_THROWS();
 	}
 
-	if (charset_len >= ICONV_CSNMAXLEN) {
+	if (charset == NULL) {
+	 	charset = get_internal_encoding();
+	} else if (charset_len >= ICONV_CSNMAXLEN) {
 		php_error_docref(NULL, E_WARNING, "Charset parameter exceeds the maximum allowed length of %d characters", ICONV_CSNMAXLEN);
 		RETURN_FALSE;
 	}
diff --git a/ext/iconv/iconv.stub.php b/ext/iconv/iconv.stub.php
index ae2a0fa0cb..a5f6743e81 100644
--- a/ext/iconv/iconv.stub.php
+++ b/ext/iconv/iconv.stub.php
@@ -2,22 +2,22 @@
 
 /** @generate-function-entries */
 
-function iconv_strlen(string $str, string $charset = UNKNOWN): int|false {}
+function iconv_strlen(string $str, ?string $charset = null): int|false {}
 
-function iconv_substr(string $str, int $offset, ?int $length = null, string $charset = UNKNOWN): string|false {}
+function iconv_substr(string $str, int $offset, ?int $length = null, ?string $charset = null): string|false {}
 
-function iconv_strpos(string $haystack, string $needle, int $offset = 0, string $charset = UNKNOWN): int|false {}
+function iconv_strpos(string $haystack, string $needle, int $offset = 0, ?string $charset = null): int|false {}
 
-function iconv_strrpos(string $haystack, string $needle, string $charset = UNKNOWN): int|false {}
+function iconv_strrpos(string $haystack, string $needle, ?string $charset = null): int|false {}
 
 function iconv_mime_encode(string $field_name, string $field_value, array $preference = []): string|false {}
 
-function iconv_mime_decode(string $encoded_string, int $mode = 0, string $charset = UNKNOWN): string|false {}
+function iconv_mime_decode(string $encoded_string, int $mode = 0, ?string $charset = null): string|false {}
 
-function iconv_mime_decode_headers(string $headers, int $mode = 0, string $charset = UNKNOWN): array|false {}
+function iconv_mime_decode_headers(string $headers, int $mode = 0, ?string $charset = null): array|false {}
 
 function iconv(string $in_charset, string $out_charset, string $str): string|false {}
 
 function iconv_set_encoding(string $type, string $charset): bool {}
 
-function iconv_get_encoding(string $type = 'all'): array|string|false {}
+function iconv_get_encoding(string $type = "all"): array|string|false {}
diff --git a/ext/iconv/iconv_arginfo.h b/ext/iconv/iconv_arginfo.h
index f182521ebe..8c50c2332b 100644
--- a/ext/iconv/iconv_arginfo.h
+++ b/ext/iconv/iconv_arginfo.h
@@ -2,27 +2,27 @@
 
 ZEND_BEGIN_ARG_WITH_RETURN_TYPE_MASK_EX(arginfo_iconv_strlen, 0, 1, MAY_BE_LONG|MAY_BE_FALSE)
 	ZEND_ARG_TYPE_INFO(0, str, IS_STRING, 0)
-	ZEND_ARG_TYPE_INFO(0, charset, IS_STRING, 0)
+	ZEND_ARG_TYPE_INFO_WITH_DEFAULT_VALUE(0, charset, IS_STRING, 1, "null")
 ZEND_END_ARG_INFO()
 
 ZEND_BEGIN_ARG_WITH_RETURN_TYPE_MASK_EX(arginfo_iconv_substr, 0, 2, MAY_BE_STRING|MAY_BE_FALSE)
 	ZEND_ARG_TYPE_INFO(0, str, IS_STRING, 0)
 	ZEND_ARG_TYPE_INFO(0, offset, IS_LONG, 0)
 	ZEND_ARG_TYPE_INFO_WITH_DEFAULT_VALUE(0, length, IS_LONG, 1, "null")
-	ZEND_ARG_TYPE_INFO(0, charset, IS_STRING, 0)
+	ZEND_ARG_TYPE_INFO_WITH_DEFAULT_VALUE(0, charset, IS_STRING, 1, "null")
 ZEND_END_ARG_INFO()
 
 ZEND_BEGIN_ARG_WITH_RETURN_TYPE_MASK_EX(arginfo_iconv_strpos, 0, 2, MAY_BE_LONG|MAY_BE_FALSE)
 	ZEND_ARG_TYPE_INFO(0, haystack, IS_STRING, 0)
 	ZEND_ARG_TYPE_INFO(0, needle, IS_STRING, 0)
 	ZEND_ARG_TYPE_INFO_WITH_DEFAULT_VALUE(0, offset, IS_LONG, 0, "0")
-	ZEND_ARG_TYPE_INFO(0, charset, IS_STRING, 0)
+	ZEND_ARG_TYPE_INFO_WITH_DEFAULT_VALUE(0, charset, IS_STRING, 1, "null")
 ZEND_END_ARG_INFO()
 
 ZEND_BEGIN_ARG_WITH_RETURN_TYPE_MASK_EX(arginfo_iconv_strrpos, 0, 2, MAY_BE_LONG|MAY_BE_FALSE)
 	ZEND_ARG_TYPE_INFO(0, haystack, IS_STRING, 0)
 	ZEND_ARG_TYPE_INFO(0, needle, IS_STRING, 0)
-	ZEND_ARG_TYPE_INFO(0, charset, IS_STRING, 0)
+	ZEND_ARG_TYPE_INFO_WITH_DEFAULT_VALUE(0, charset, IS_STRING, 1, "null")
 ZEND_END_ARG_INFO()
 
 ZEND_BEGIN_ARG_WITH_RETURN_TYPE_MASK_EX(arginfo_iconv_mime_encode, 0, 2, MAY_BE_STRING|MAY_BE_FALSE)
@@ -34,13 +34,13 @@ ZEND_END_ARG_INFO()
 ZEND_BEGIN_ARG_WITH_RETURN_TYPE_MASK_EX(arginfo_iconv_mime_decode, 0, 1, MAY_BE_STRING|MAY_BE_FALSE)
 	ZEND_ARG_TYPE_INFO(0, encoded_string, IS_STRING, 0)
 	ZEND_ARG_TYPE_INFO_WITH_DEFAULT_VALUE(0, mode, IS_LONG, 0, "0")
-	ZEND_ARG_TYPE_INFO(0, charset, IS_STRING, 0)
+	ZEND_ARG_TYPE_INFO_WITH_DEFAULT_VALUE(0, charset, IS_STRING, 1, "null")
 ZEND_END_ARG_INFO()
 
 ZEND_BEGIN_ARG_WITH_RETURN_TYPE_MASK_EX(arginfo_iconv_mime_decode_headers, 0, 1, MAY_BE_ARRAY|MAY_BE_FALSE)
 	ZEND_ARG_TYPE_INFO(0, headers, IS_STRING, 0)
 	ZEND_ARG_TYPE_INFO_WITH_DEFAULT_VALUE(0, mode, IS_LONG, 0, "0")
-	ZEND_ARG_TYPE_INFO(0, charset, IS_STRING, 0)
+	ZEND_ARG_TYPE_INFO_WITH_DEFAULT_VALUE(0, charset, IS_STRING, 1, "null")
 ZEND_END_ARG_INFO()
 
 ZEND_BEGIN_ARG_WITH_RETURN_TYPE_MASK_EX(arginfo_iconv, 0, 3, MAY_BE_STRING|MAY_BE_FALSE)
@@ -55,7 +55,7 @@ ZEND_BEGIN_ARG_WITH_RETURN_TYPE_INFO_EX(arginfo_iconv_set_encoding, 0, 2, _IS_BO
 ZEND_END_ARG_INFO()
 
 ZEND_BEGIN_ARG_WITH_RETURN_TYPE_MASK_EX(arginfo_iconv_get_encoding, 0, 0, MAY_BE_ARRAY|MAY_BE_STRING|MAY_BE_FALSE)
-	ZEND_ARG_TYPE_INFO_WITH_DEFAULT_VALUE(0, type, IS_STRING, 0, "\'all\'")
+	ZEND_ARG_TYPE_INFO_WITH_DEFAULT_VALUE(0, type, IS_STRING, 0, "\"all\"")
 ZEND_END_ARG_INFO()
 
 
diff --git a/ext/libxml/libxml.c b/ext/libxml/libxml.c
index f015c71d24..febc5eca2d 100644
--- a/ext/libxml/libxml.c
+++ b/ext/libxml/libxml.c
@@ -913,11 +913,11 @@ PHP_FUNCTION(libxml_set_streams_context)
 PHP_FUNCTION(libxml_use_internal_errors)
 {
 	xmlStructuredErrorFunc current_handler;
-	zend_bool use_errors=0, retval;
+	zend_bool use_errors, use_errors_is_null = 1, retval;
 
 	ZEND_PARSE_PARAMETERS_START(0, 1)
 		Z_PARAM_OPTIONAL
-		Z_PARAM_BOOL(use_errors)
+		Z_PARAM_BOOL_OR_NULL(use_errors, use_errors_is_null)
 	ZEND_PARSE_PARAMETERS_END();
 
 	current_handler = xmlStructuredError;
@@ -927,7 +927,7 @@ PHP_FUNCTION(libxml_use_internal_errors)
 		retval = 0;
 	}
 
-	if (ZEND_NUM_ARGS() == 0) {
+	if (use_errors_is_null) {
 		RETURN_BOOL(retval);
 	}
 
diff --git a/ext/libxml/libxml.stub.php b/ext/libxml/libxml.stub.php
index 729b91a2ec..74a15e9169 100644
--- a/ext/libxml/libxml.stub.php
+++ b/ext/libxml/libxml.stub.php
@@ -5,7 +5,7 @@
 /** @param resource $context */
 function libxml_set_streams_context($context): void {}
 
-function libxml_use_internal_errors(bool $use_errors = UNKNOWN): bool {}
+function libxml_use_internal_errors(?bool $use_errors = null): bool {}
 
 function libxml_get_last_error(): LibXMLError|false {}
 
diff --git a/ext/libxml/libxml_arginfo.h b/ext/libxml/libxml_arginfo.h
index 3b11e1a554..5d28e7df7e 100644
--- a/ext/libxml/libxml_arginfo.h
+++ b/ext/libxml/libxml_arginfo.h
@@ -5,7 +5,7 @@ ZEND_BEGIN_ARG_WITH_RETURN_TYPE_INFO_EX(arginfo_libxml_set_streams_context, 0, 1
 ZEND_END_ARG_INFO()
 
 ZEND_BEGIN_ARG_WITH_RETURN_TYPE_INFO_EX(arginfo_libxml_use_internal_errors, 0, 0, _IS_BOOL, 0)
-	ZEND_ARG_TYPE_INFO(0, use_errors, _IS_BOOL, 0)
+	ZEND_ARG_TYPE_INFO_WITH_DEFAULT_VALUE(0, use_errors, _IS_BOOL, 1, "null")
 ZEND_END_ARG_INFO()
 
 ZEND_BEGIN_ARG_WITH_RETURN_OBJ_TYPE_MASK_EX(arginfo_libxml_get_last_error, 0, 0, LibXMLError, MAY_BE_FALSE)
diff --git a/ext/mysqli/mysqli.c b/ext/mysqli/mysqli.c
index 7509b04c88..17452bf287 100644
--- a/ext/mysqli/mysqli.c
+++ b/ext/mysqli/mysqli.c
@@ -1003,36 +1003,19 @@ PHP_FUNCTION(mysqli_stmt_construct)
 	zval				*mysql_link;
 	MY_STMT				*stmt;
 	MYSQLI_RESOURCE		*mysqli_resource;
-	char				*statement;
+	char				*statement = NULL;
 	size_t					statement_len;
 
-	switch (ZEND_NUM_ARGS())
-	{
-		case 1:  /* mysql_stmt_init */
-			if (zend_parse_parameters(1, "O", &mysql_link, mysqli_link_class_entry)==FAILURE) {
-				RETURN_THROWS();
-			}
-			MYSQLI_FETCH_RESOURCE_CONN(mysql, mysql_link, MYSQLI_STATUS_VALID);
-
-			stmt = (MY_STMT *)ecalloc(1,sizeof(MY_STMT));
-
-			stmt->stmt = mysql_stmt_init(mysql->mysql);
-		break;
-		case 2:
-			if (zend_parse_parameters(2, "Os", &mysql_link, mysqli_link_class_entry, &statement, &statement_len)==FAILURE) {
-				RETURN_THROWS();
-			}
-			MYSQLI_FETCH_RESOURCE_CONN(mysql, mysql_link, MYSQLI_STATUS_VALID);
+	if (zend_parse_parameters(ZEND_NUM_ARGS(), "O|s!", &mysql_link, mysqli_link_class_entry, &statement, &statement_len) == FAILURE) {
+		RETURN_THROWS();
+	}
 
-			stmt = (MY_STMT *)ecalloc(1,sizeof(MY_STMT));
+	MYSQLI_FETCH_RESOURCE_CONN(mysql, mysql_link, MYSQLI_STATUS_VALID);
 
-			if ((stmt->stmt = mysql_stmt_init(mysql->mysql))) {
-				mysql_stmt_prepare(stmt->stmt, (char *)statement, statement_len);
-			}
-		break;
-		default:
-			WRONG_PARAM_COUNT;
-		break;
+	stmt = (MY_STMT *) ecalloc(1, sizeof(MY_STMT));
+	stmt->stmt = mysql_stmt_init(mysql->mysql);
+	if (stmt->stmt && statement) {
+		mysql_stmt_prepare(stmt->stmt, (char *)statement, statement_len);
 	}
 
 	if (!stmt->stmt) {
diff --git a/ext/mysqli/mysqli.stub.php b/ext/mysqli/mysqli.stub.php
index 5d8a75148d..0bf9fb2bf1 100644
--- a/ext/mysqli/mysqli.stub.php
+++ b/ext/mysqli/mysqli.stub.php
@@ -28,7 +28,7 @@ class mysqli
      * @return bool
      * @alias mysqli_begin_transaction
      */
-    public function begin_transaction(int $flags = 0, string $name = UNKNOWN) {}
+    public function begin_transaction(int $flags = 0, ?string $name = null) {}
 
     /**
      * @return bool
@@ -52,7 +52,7 @@ class mysqli
      * @return bool
      * @alias mysqli_commit
      */
-    public function commit(int $flags = -1, string $name = UNKNOWN) {}
+    public function commit(int $flags = -1, ?string $name = null) {}
 
     /**
      * @return mysqli|null|false
@@ -217,7 +217,7 @@ class mysqli
      * @return bool
      * @alias mysqli_rollback
      */
-    public function rollback(int $flags = 0, string $name = '') {}
+    public function rollback(int $flags = 0, ?string $name = null) {}
 
     /**
      * @return bool
@@ -389,7 +389,7 @@ class mysqli_result
 class mysqli_stmt
 {
     /** @alias mysqli_stmt_construct */
-    public function __construct(mysqli $mysqli_link, string $statement = UNKNOWN) {}
+    public function __construct(mysqli $mysqli_link, ?string $statement = null) {}
 
     /**
      * @return int|false
@@ -526,7 +526,7 @@ function mysqli_affected_rows(mysqli $mysql_link): int|string {}
 
 function mysqli_autocommit(mysqli $mysql_link, bool $mode): bool {}
 
-function mysqli_begin_transaction(mysqli $mysql_link, int $flags = 0, string $name = UNKNOWN): bool {}
+function mysqli_begin_transaction(mysqli $mysql_link, int $flags = 0, ?string $name = null): bool {}
 
 function mysqli_change_user(mysqli $mysql_link, string $user, string $password, ?string $database): bool {}
 
@@ -534,7 +534,7 @@ function mysqli_character_set_name(mysqli $mysql_link): ?string {}
 
 function mysqli_close(mysqli $mysql_link): bool {}
 
-function mysqli_commit(mysqli $mysql_link, int $flags = -1, string $name = UNKNOWN): bool {}
+function mysqli_commit(mysqli $mysql_link, int $flags = -1, ?string $name = null): bool {}
 
 function mysqli_connect(
     ?string $host = null,
@@ -668,7 +668,7 @@ function mysqli_reap_async_query(mysqli $mysqli_link): mysqli_result|bool {}
 
 function mysqli_release_savepoint(mysqli $mysqli_link, string $name): bool {}
 
-function mysqli_rollback(mysqli $mysqli_link, int $flags = 0, string $name = ''): bool {}
+function mysqli_rollback(mysqli $mysqli_link, int $flags = 0, ?string $name = null): bool {}
 
 function mysqli_savepoint(mysqli $mysqli_link, string $name): bool {}
 
diff --git a/ext/mysqli/mysqli_api.c b/ext/mysqli/mysqli_api.c
index 3e7bbcb11c..f391cd6234 100644
--- a/ext/mysqli/mysqli_api.c
+++ b/ext/mysqli/mysqli_api.c
@@ -738,9 +738,9 @@ PHP_FUNCTION(mysqli_commit)
 	zval		*mysql_link;
 	zend_long		flags = TRANS_COR_NO_OPT;
 	char *		name = NULL;
-	size_t			name_len = 0;
+	size_t			name_len;
 
-	if (zend_parse_method_parameters(ZEND_NUM_ARGS(), getThis(), "O|ls", &mysql_link, mysqli_link_class_entry, &flags, &name, &name_len) == FAILURE) {
+	if (zend_parse_method_parameters(ZEND_NUM_ARGS(), getThis(), "O|ls!", &mysql_link, mysqli_link_class_entry, &flags, &name, &name_len) == FAILURE) {
 		RETURN_THROWS();
 	}
 	MYSQLI_FETCH_RESOURCE_CONN(mysql, mysql_link, MYSQLI_STATUS_VALID);
@@ -1981,7 +1981,7 @@ PHP_FUNCTION(mysqli_rollback)
 	char *		name = NULL;
 	size_t			name_len = 0;
 
-	if (zend_parse_method_parameters(ZEND_NUM_ARGS(), getThis(), "O|ls", &mysql_link, mysqli_link_class_entry, &flags, &name, &name_len) == FAILURE) {
+	if (zend_parse_method_parameters(ZEND_NUM_ARGS(), getThis(), "O|ls!", &mysql_link, mysqli_link_class_entry, &flags, &name, &name_len) == FAILURE) {
 		RETURN_THROWS();
 	}
 	MYSQLI_FETCH_RESOURCE_CONN(mysql, mysql_link, MYSQLI_STATUS_VALID);
diff --git a/ext/mysqli/mysqli_arginfo.h b/ext/mysqli/mysqli_arginfo.h
index bbc489f6be..80c5fcd7cb 100644
--- a/ext/mysqli/mysqli_arginfo.h
+++ b/ext/mysqli/mysqli_arginfo.h
@@ -12,7 +12,7 @@ ZEND_END_ARG_INFO()
 ZEND_BEGIN_ARG_WITH_RETURN_TYPE_INFO_EX(arginfo_mysqli_begin_transaction, 0, 1, _IS_BOOL, 0)
 	ZEND_ARG_OBJ_INFO(0, mysql_link, mysqli, 0)
 	ZEND_ARG_TYPE_INFO_WITH_DEFAULT_VALUE(0, flags, IS_LONG, 0, "0")
-	ZEND_ARG_TYPE_INFO(0, name, IS_STRING, 0)
+	ZEND_ARG_TYPE_INFO_WITH_DEFAULT_VALUE(0, name, IS_STRING, 1, "null")
 ZEND_END_ARG_INFO()
 
 ZEND_BEGIN_ARG_WITH_RETURN_TYPE_INFO_EX(arginfo_mysqli_change_user, 0, 4, _IS_BOOL, 0)
@@ -33,7 +33,7 @@ ZEND_END_ARG_INFO()
 ZEND_BEGIN_ARG_WITH_RETURN_TYPE_INFO_EX(arginfo_mysqli_commit, 0, 1, _IS_BOOL, 0)
 	ZEND_ARG_OBJ_INFO(0, mysql_link, mysqli, 0)
 	ZEND_ARG_TYPE_INFO_WITH_DEFAULT_VALUE(0, flags, IS_LONG, 0, "-1")
-	ZEND_ARG_TYPE_INFO(0, name, IS_STRING, 0)
+	ZEND_ARG_TYPE_INFO_WITH_DEFAULT_VALUE(0, name, IS_STRING, 1, "null")
 ZEND_END_ARG_INFO()
 
 ZEND_BEGIN_ARG_WITH_RETURN_OBJ_TYPE_MASK_EX(arginfo_mysqli_connect, 0, 0, mysqli, MAY_BE_NULL|MAY_BE_FALSE)
@@ -265,7 +265,7 @@ ZEND_END_ARG_INFO()
 ZEND_BEGIN_ARG_WITH_RETURN_TYPE_INFO_EX(arginfo_mysqli_rollback, 0, 1, _IS_BOOL, 0)
 	ZEND_ARG_OBJ_INFO(0, mysqli_link, mysqli, 0)
 	ZEND_ARG_TYPE_INFO_WITH_DEFAULT_VALUE(0, flags, IS_LONG, 0, "0")
-	ZEND_ARG_TYPE_INFO_WITH_DEFAULT_VALUE(0, name, IS_STRING, 0, "\'\'")
+	ZEND_ARG_TYPE_INFO_WITH_DEFAULT_VALUE(0, name, IS_STRING, 1, "null")
 ZEND_END_ARG_INFO()
 
 #define arginfo_mysqli_savepoint arginfo_mysqli_release_savepoint
@@ -431,7 +431,7 @@ ZEND_END_ARG_INFO()
 
 ZEND_BEGIN_ARG_INFO_EX(arginfo_class_mysqli_begin_transaction, 0, 0, 0)
 	ZEND_ARG_TYPE_INFO_WITH_DEFAULT_VALUE(0, flags, IS_LONG, 0, "0")
-	ZEND_ARG_TYPE_INFO(0, name, IS_STRING, 0)
+	ZEND_ARG_TYPE_INFO_WITH_DEFAULT_VALUE(0, name, IS_STRING, 1, "null")
 ZEND_END_ARG_INFO()
 
 ZEND_BEGIN_ARG_INFO_EX(arginfo_class_mysqli_change_user, 0, 0, 3)
@@ -447,7 +447,7 @@ ZEND_END_ARG_INFO()
 
 ZEND_BEGIN_ARG_INFO_EX(arginfo_class_mysqli_commit, 0, 0, 0)
 	ZEND_ARG_TYPE_INFO_WITH_DEFAULT_VALUE(0, flags, IS_LONG, 0, "-1")
-	ZEND_ARG_TYPE_INFO(0, name, IS_STRING, 0)
+	ZEND_ARG_TYPE_INFO_WITH_DEFAULT_VALUE(0, name, IS_STRING, 1, "null")
 ZEND_END_ARG_INFO()
 
 #define arginfo_class_mysqli_connect arginfo_class_mysqli___construct
@@ -530,10 +530,7 @@ ZEND_BEGIN_ARG_INFO_EX(arginfo_class_mysqli_release_savepoint, 0, 0, 1)
 	ZEND_ARG_TYPE_INFO(0, name, IS_STRING, 0)
 ZEND_END_ARG_INFO()
 
-ZEND_BEGIN_ARG_INFO_EX(arginfo_class_mysqli_rollback, 0, 0, 0)
-	ZEND_ARG_TYPE_INFO_WITH_DEFAULT_VALUE(0, flags, IS_LONG, 0, "0")
-	ZEND_ARG_TYPE_INFO_WITH_DEFAULT_VALUE(0, name, IS_STRING, 0, "\'\'")
-ZEND_END_ARG_INFO()
+#define arginfo_class_mysqli_rollback arginfo_class_mysqli_begin_transaction
 
 #define arginfo_class_mysqli_savepoint arginfo_class_mysqli_release_savepoint
 
@@ -622,7 +619,7 @@ ZEND_END_ARG_INFO()
 
 ZEND_BEGIN_ARG_INFO_EX(arginfo_class_mysqli_stmt___construct, 0, 0, 1)
 	ZEND_ARG_OBJ_INFO(0, mysqli_link, mysqli, 0)
-	ZEND_ARG_TYPE_INFO(0, statement, IS_STRING, 0)
+	ZEND_ARG_TYPE_INFO_WITH_DEFAULT_VALUE(0, statement, IS_STRING, 1, "null")
 ZEND_END_ARG_INFO()
 
 ZEND_BEGIN_ARG_INFO_EX(arginfo_class_mysqli_stmt_attr_get, 0, 0, 1)
diff --git a/ext/mysqli/mysqli_nonapi.c b/ext/mysqli/mysqli_nonapi.c
index 97d648dc2f..bc6cafb69b 100644
--- a/ext/mysqli/mysqli_nonapi.c
+++ b/ext/mysqli/mysqli_nonapi.c
@@ -1176,7 +1176,7 @@ PHP_FUNCTION(mysqli_begin_transaction)
 	size_t			name_len = -1;
 	zend_bool	err = FALSE;
 
-	if (zend_parse_method_parameters(ZEND_NUM_ARGS(), getThis(), "O|ls", &mysql_link, mysqli_link_class_entry, &flags, &name, &name_len) == FAILURE) {
+	if (zend_parse_method_parameters(ZEND_NUM_ARGS(), getThis(), "O|ls!", &mysql_link, mysqli_link_class_entry, &flags, &name, &name_len) == FAILURE) {
 		RETURN_THROWS();
 	}
 	MYSQLI_FETCH_RESOURCE_CONN(mysql, mysql_link, MYSQLI_STATUS_VALID);