Revert "Prepare for PHP 8.1"

This reverts commit 1ab4d0e6b7abb67d5a01ce3327bf973772271fb2.
This reverts commit a359635cb1a4df8b5137a506c88c4cb102acac0e.

1 files changed, 1005 insertions, 1 deletions

diff --git a/UPGRADING b/UPGRADING
index 078cb78077..15e19f2782 100644
--- a/UPGRADING
+++ b/UPGRADING
@@ -1,4 +1,4 @@
-PHP 8.1 UPGRADE NOTES
+PHP 8.0 UPGRADE NOTES
 
 1. Backward Incompatible Changes
 2. New Features
@@ -20,54 +20,1058 @@ PHP 8.1 UPGRADE NOTES
 1. Backward Incompatible Changes
 ========================================
 
+- Core:
+  . Assertion failures now throw by default. If the old behavior is desired,
+    then set `assert.exception=0` in INI settings.
+  . Methods with the same name as the class are no longer interpreted as
+    constructors. The __construct() method should be used instead.
+  . Removed ability to call non-static methods statically.
+  . Removed (unset) cast.
+  . Removed track_errors ini directive. This means that $php_errormsg is no
+    longer available. The error_get_last() function may be used instead.
+  . Removed the ability to define case-insensitive constants. The third
+    argument to define() may no longer be true.
+  . Access to undefined constants now always results in an Error exception.
+    Previously, unqualified constant accesses resulted in a warning and were
+    interpreted as strings.
+  . Removed ability to specify an autoloader using an __autoload() function.
+    spl_autoload_register() should be used instead.
+  . Removed the $errcontext argument for custom error handlers.
+  . Removed create_function(). Anonymous functions may be used instead.
+  . Removed each(). foreach or ArrayIterator should be used instead.
+  . Removed ability to unbind $this from closures that were created from a
+    method, using Closure::fromCallable() or ReflectionMethod::getClosure().
+  . Also removed ability to unbind $this from proper closures that contain uses
+    of $this.
+  . Removed ability to use array_key_exists() with objects. Use one of isset()
+    or property_exists() instead.
+  . Made the behavior of array_key_exists() regarding the type of the key
+    parameter consistent with isset() and normal array access. All key types now
+    use the usual coercions and array/object keys throw a TypeError.
+  . Any array that has a number n as its first numeric key will use n+1 for
+    its next implicit key, even if n is negative.
+    RFC: https://wiki.php.net/rfc/negative_array_index
+  . The default error_reporting level is now E_ALL. Previously it excluded
+    E_NOTICE and E_DEPRECATED.
+  . display_startup_errors is now enabled by default.
+  . Using "parent" inside a class that has no parent will now result in a
+    fatal compile-time error.
+  . The @ operator will no longer silence fatal errors (E_ERROR, E_CORE_ERROR,
+    E_COMPILE_ERROR, E_USER_ERROR, E_RECOVERABLE_ERROR, E_PARSE). Error handlers
+    that expect error_reporting to be 0 when @ is used, should be adjusted to
+    use a mask check instead:
+
+        // Replace
+        function my_error_handler($err_no, $err_msg, $filename, $linenum) {
+            if (error_reporting() == 0) {
+                return; // Silenced
+            }
+            // ...
+        }
+
+        // With
+        function my_error_handler($err_no, $err_msg, $filename, $linenum) {
+            if (!(error_reporting() & $err_no)) {
+                return; // Silenced
+            }
+            // ...
+        }
+
+    Additionally, care should be taken that error messages are not displayed in
+    production environments, which can result in information leaks. Please
+    ensure that display_errors=Off is used in conjunction with error logging.
+  . Adding more than one @ operator to an expression is no longer supported,
+    since this syntax is now used for attributes (previously extra @ operators
+    had no effect).
+    RFC: https://wiki.php.net/rfc/shorter_attribute_syntax
+  . Inheritance errors due to incompatible method signatures (LSP violations)
+    will now always generate a fatal error. Previously a warning was generated
+    in some cases.
+    RFC: https://wiki.php.net/rfc/lsp_errors
+  . The precedence of the concatenation operator has changed relative to
+    bitshifts and addition as well as subtraction.
+    RFC: https://wiki.php.net/rfc/concatenation_precedence
+  . Arguments with a default value that resolves to null at runtime will no
+    longer implicitly mark the argument type as nullable. Either use an explicit
+    nullable type, or an explicit null default value instead.
+
+        // Replace
+        function test(int $arg = CONST_RESOLVING_TO_NULL) {}
+        // With
+        function test(?int $arg = CONST_RESOLVING_TO_NULL) {}
+        // Or
+        function test(int $arg = null) {}
+  . A number of warnings have been converted into Error exceptions:
+
+    * Attempting to write to a property of a non-object. Previously this
+      implicitly created an stdClass object for null, false and empty strings.
+    * Attempting to append an element to an array for which the PHP_INT_MAX key
+      is already used.
+    * Attempting to use an invalid type (array or object) as an array key or
+      string offset.
+    * Attempting to write to an array index of a scalar value.
+    * Attempting to unpack a non-array/Traversable.
+
+    A number of notices have been converted into warnings:
+
+    * Attempting to read an undefined variable.
+    * Attempting to read an undefined property.
+    * Attempting to read an undefined array key.
+    * Attempting to read a property of a non-object.
+    * Attempting to access an array index of a non-array.
+    * Attempting to convert an array to string.
+    * Attempting to use a resource as an array key.
+    * Attempting to use null, a boolean, or a float as a string offset.
+    * Attempting to read an out-of-bounds string offset.
+    * Attempting to assign an empty string to a string offset.
+
+    RFC: https://wiki.php.net/rfc/engine_warnings
+  . Attempting to assign multiple bytes to a string offset will now emit a
+    warning.
+  . Unexpected characters in source files (such as null bytes outside of
+    strings) will now result in a ParseError exception instead of a compile
+    warning.
+  . Uncaught exceptions now go through "clean shutdown", which means that
+    destructors will be called after an uncaught exception.
+  . Compile time fatal error "Only variables can be passed by reference" has
+    been delayed until runtime and converted to "Cannot pass parameter by
+    reference" exception.
+  . Some "Only variables should be passed by reference" notices have been
+    converted to "Cannot pass parameter by reference" exception.
+  . The generated name for anonymous classes has changed. It will now include
+    the name of the first parent or interface:
+
+        new class extends ParentClass {};
+        // -> ParentClass@anonymous
+        new class implements FirstInterface, SecondInterface {};
+        // -> FirstInterface@anonymous
+        new class {};
+        // -> class@anonymous
+
+    The name shown above is still followed by a null byte and and a unique
+    suffix.
+  . Non-absolute trait method references in trait alias adaptations are now
+    required to be unambiguous:
+
+        class X {
+            use T1, T2 {
+               func as otherFunc;
+            }
+            function func() {}
+        }
+
+    If both T1::func() and T2::func() exist, this code was previously silently
+    accepted, and func as assumed to refer to T1::func. Now it will generate a
+    fatal error instead, and either T1::func or T2::func needs to be written
+    explicitly.
+  . The signature of abstract methods defined in traits is now checked against
+    the implementing class method:
+
+        trait MyTrait {
+            abstract private function neededByTrait(): string;
+        }
+
+        class MyClass {
+            use MyTrait;
+
+            // Error, because of return type mismatch.
+            private function neededByTrait(): int { return 42; }
+        }
+
+    RFC: https://wiki.php.net/rfc/abstract_trait_method_validation
+  . Disabled functions are now treated exactly like non-existent functions.
+    Calling a disabled function will report it as unknown, and redefining a
+    disabled function is now possible.
+  . data: stream wrappers are no longer writable, which matches the documented
+    behavior.
+  . The arithmetic and bitwise operators
+    +, -, *, /, **, %, <<, >>, &, |, ^, ~, ++, --
+    will now consistently throw a TypeError when one of the operands is an
+    array, resource or non-overloaded object. The only exception to this is the
+    array + array merge operation, which remains supported.
+    RFC: https://wiki.php.net/rfc/arithmetic_operator_type_checks
+  . Float to string casting will now always behave locale-independently.
+    RFC: https://wiki.php.net/rfc/locale_independent_float_to_string
+  . Removed support for deprecated curly braces for offset access
+    RFC: https://wiki.php.net/rfc/deprecate_curly_braces_array_access
+  . Applying the final modifier on a private method will now produce a warning
+    unless that method is the constructor.
+    RFC: https://wiki.php.net/rfc/inheritance_private_methods
+  . If an object constructor exit()s, the object destructor will no longer be
+    called. This matches the behavior when the constructor throws.
+  . Non-strict comparisons between numbers and non-numeric strings now work by
+    casting the number to string and comparing the strings. Comparisons between
+    numbers and numeric strings continue to work as before. Notably, this means
+    that `0 == "not-a-number"` is considered false now.
+    RFC: https://wiki.php.net/rfc/string_to_number_comparison
+  . Namespaced names can no longer contain whitespace: While `Foo\Bar` will be
+    recognized as a namespaced name, `Foo \ Bar` will not. Conversely, reserved
+    keywords are now permitted as namespace segments.
+    RFC: https://wiki.php.net/rfc/namespaced_names_as_token
+  . Nested ternaries now require explicit parentheses.
+    RFC: https://wiki.php.net/rfc/ternary_associativity
+  . debug_backtrace() and Exception::getTrace() will no longer provide
+    references to arguments. It will not be possible to change function
+    arguments through the backtrace.
+  . Numeric string handling has been altered to be more intuitive and less
+    error-prone. Trailing whitespace is now allowed in numeric strings for
+    consistency with how leading whitespace is treated. This mostly affects:
+     - The is_numeric() function
+     - String-to-string comparisons
+     - Type declarations
+     - Increment and decrement operations
+    The concept of a "leading-numeric string" has been mostly dropped; the
+    cases where this remains exist in order to ease migration. Strings which
+    emitted an E_NOTICE "A non well-formed numeric value encountered" will now
+    emit an E_WARNING "A non-numeric value encountered" and all strings which
+    emitted an E_WARNING "A non-numeric value encountered" will now throw a
+    TypeError. This mostly affects:
+     - Arithmetic operations
+     - Bitwise operations
+    This E_WARNING to TypeError change also affects the E_WARNING
+    "Illegal string offset 'string'" for illegal string offsets. The behavior
+    of explicit casts to int/float from strings has not been changed.
+    RFC: https://wiki.php.net/rfc/saner-numeric-strings
+  . Magic Methods will now have their arguments and return types checked if
+    they have them declared. The signatures should match the following list:
+
+      __call(string $name, array $arguments): mixed
+      __callStatic(string $name, array $arguments): mixed
+      __clone(): void
+      __debugInfo(): ?array
+      __get(string $name): mixed
+      __invoke(mixed $arguments): mixed
+      __isset(string $name): bool
+      __serialize(): array
+      __set(string $name, mixed $value): void
+      __set_state(array $properties): object
+      __sleep(): array
+      __unserialize(array $data): void
+      __unset(string $name): void
+      __wakeup(): void
+
+    RFC: https://wiki.php.net/rfc/magic-methods-signature
+
+- COM:
+  . Removed the ability to import case-insensitive constants from type
+    libraries. The second argument to com_load_typelib() may no longer be false;
+    com.autoregister_casesensitive may no longer be disabled; case-insensitive
+    markers in com.typelib_file are ignored.
+
+- Curl:
+  . CURLOPT_POSTFIELDS no longer accepts objects as arrays. To interpret an
+    object as an array, perform an explicit (array) cast. The same applies to
+    other options accepting arrays as well.
+
+- Date:
+  . mktime() and gmmktime() now require at least one argument. time() can be
+    used to get the current timestamp.
+
+- dom:
+  . Remove unimplemented classes from ext/dom that had no behavior and contained
+    test data. These classes have also been removed in the latest version of DOM
+    standard:
+
+     * DOMNameList
+     * DomImplementationList
+     * DOMConfiguration
+     * DomError
+     * DomErrorHandler
+     * DOMImplementationSource
+     * DOMLocator
+     * DOMUserDataHandler
+     * DOMTypeInfo
+
+- Enchant:
+  . enchant_broker_list_dicts(), enchant_broker_describe() and
+    enchant_dict_suggest() will now return an empty array instead of null.
+  . enchant_broker_init() will now return an EnchantBroker object rather than
+    a resource. Return value checks using is_resource() should be replaced with
+    checks for `false`.
+  . enchant_broker_request_dict() and enchant_broker_request_pwl_dict() will now
+    return an EnchantDictionary object rather than a resource. Return value
+    checks using is_resource() should be replaced with checks for `false`.
+
+- Exif:
+  . Removed read_exif_data(). exif_read_data() should be used instead.
+
+- Filter:
+  . The FILTER_FLAG_SCHEME_REQUIRED and FILTER_FLAG_HOST_REQUIRED flags for the
+    FILTER_VALIDATE_URL filter have been removed. The scheme and host are (and
+    have been) always required.
+  . The INPUT_REQUEST and INPUT_SESSION source for filter_input() etc have been
+    removed. These were never implemented and their use always generated a
+    warning.
+
+- GD:
+  . The GD extension now uses objects as the underlying data structure for
+    images, rather than resources. These objects are completely opaque, i.e.
+    they don't have any methods.
+  . The deprecated function image2wbmp() has been removed.
+    RFC: https://wiki.php.net/rfc/image2wbmp
+  . The deprecated functions png2wbmp() and jpeg2wbmp() have been removed.
+    RFC: https://wiki.php.net/rfc/deprecate-png-jpeg-2wbmp
+  . The default $mode parameter of imagecropauto() no longer accepts -1.
+    IMG_CROP_DEFAULT should be used instead.
+
+- GMP:
+  . gmp_random() has been removed. One of gmp_random_range() or
+    gmp_random_bits() should be used instead.
+
+- Iconv:
+  . iconv() implementations which do not properly set errno in case of errors
+    are no longer supported.
+
+- Intl:
+  . The deprecated constant INTL_IDNA_VARIANT_2003 has been removed.
+    RFC: https://wiki.php.net/rfc/deprecate-and-remove-intl_idna_variant_2003
+  . The deprecated Normalizer::NONE constant has been removed.
+  . The IntlDateFormatter::RELATIVE_FULL, IntlDateFormatter::RELATIVE_LONG,
+    IntlDateFormatter::RELATIVE_MEDIUM, and IntlDateFormatter::RELATIVE_SHORT
+    constants have been added.
+
+- LDAP:
+  . The deprecated function ldap_sort has been removed.
+  . The interface of ldap_set_rebind_proc has changed; the $callback parameter
+    does not accept empty string anymore; null value shall be used instead.
+
+- Mbstring:
+  . The mbstring.func_overload directive has been removed. The related
+    MB_OVERLOAD_MAIL, MB_OVERLOAD_STRING, and MB_OVERLOAD_REGEX constants have
+    also been removed. Finally, the "func_overload" and "func_overload_list"
+    entries in mb_get_info() have been removed.
+  . mb_parse_str() can no longer be used without specifying a result array.
+  . A number of deprecated mbregex aliases have been removed. See the following
+    list for which functions should be used instead:
+
+     * mbregex_encoding()      -> mb_regex_encoding()
+     * mbereg()                -> mb_ereg()
+     * mberegi()               -> mb_eregi()
+     * mbereg_replace()        -> mb_ereg_replace()
+     * mberegi_replace()       -> mb_eregi_replace()
+     * mbsplit()               -> mb_split()
+     * mbereg_match()          -> mb_ereg_match()
+     * mbereg_search()         -> mb_ereg_search()
+     * mbereg_search_pos()     -> mb_ereg_search_pos()
+     * mbereg_search_regs()    -> mb_ereg_search_regs()
+     * mbereg_search_init()    -> mb_ereg_search_init()
+     * mbereg_search_getregs() -> mb_ereg_search_getregs()
+     * mbereg_search_getpos()  -> mb_ereg_search_getpos()
+     * mbereg_search_setpos()  -> mb_ereg_search_setpos()
+
+  . The 'e' modifier for mb_ereg_replace() has been removed.
+    mb_ereg_replace_callback() should be used instead.
+  . A non-string pattern argument to mb_ereg_replace() will now be interpreted
+    as a string instead of an ASCII codepoint. The previous behavior may be
+    restored with an explicit call to chr().
+  . The needle argument for mb_strpos(), mb_strrpos(), mb_stripos(),
+    mb_strripos(), mb_strstr(), mb_stristr(), mb_strrchr() and mb_strrichr() can
+    now be empty.
+  . The $is_hex parameter, which was not used internally, has been removed from
+    mb_decode_numericentity().
+  . The legacy behavior of passing the encoding as the third argument instead
+    of an offset for the mb_strrpos() function has been removed; provide an
+    explicit 0 offset with the encoding as the fourth argument instead.
+  . The ISO_8859-* character encoding aliases have been replaced by ISO8859-*
+    aliases for better interoperability with the iconv extension. The mbregex
+    ISO 8859 aliases with underscores (ISO_8859_* and ISO8859_*) have also been
+    removed.
+
+- OCI8:
+  . Several alias functions have been marked as deprecated.
+  . oci_internal_debug() and its alias ociinternaldebug() have been removed.
+
+- OpenSSL:
+  . openssl_x509_read() and openssl_csr_sign() will now return an
+    OpenSSLCertificate object rather than a resource. Return value checks using
+    is_resource() should be replaced with checks for `false`.
+  . The openssl_x509_free() function is deprecated and no longer has an effect,
+    instead the OpenSSLCertificate instance is automatically destroyed if it is no
+    longer referenced.
+  . openssl_csr_new() will now return an OpenSSLCertificateSigningRequest object
+    rather than a resource. Return value checks using is_resource() should be
+    replaced with checks for `false`.
+  . openssl_pkey_new() will now return an OpenSSLAsymmetricKey object rather than a
+    resource. Return value checks using is_resource() should be replaced with
+    checks for `false`.
+  . The openssl_pkey_free() function is deprecated and no longer has an effect,
+    instead the OpenSSLAsymmetricKey instance is automatically destroyed if it is no
+    longer referenced.
+
+- PCRE:
+  . When passing invalid escape sequences they are no longer interpreted as
+    literals. This behavior previously required the X modifier - which is
+    now ignored.
+
+- PDO:
+  . The default error handling mode has been changed from "silent" to
+    "exceptions". See https://www.php.net/manual/en/pdo.error-handling.php
+    for details of behavior changes and how to explicitly set this attribute.
+    RFC: https://wiki.php.net/rfc/pdo_default_errmode
+  . The signatures of some PDO methods have changed:
+
+        PDO::query(
+            string $statement, ?int $fetch_mode = null, ...$fetch_mode_args)
+        PDOStatement::setFetchMode(int $mode, ...$params)
+
+- PDO_ODBC:
+  . The php.ini directive pdo_odbc.db2_instance_name has been removed
+
+- Phar:
+  . Metadata associated with a phar will no longer be automatically unserialized,
+    to fix potential security vulnerabilities due to object instantiation, autoloading, etc.
+    RFC: https://wiki.php.net/rfc/phar_stop_autoloading_metadata
+
+- Reflection:
+  . The method signatures
+
+        ReflectionClass::newInstance($args)
+        ReflectionFunction::invoke($args)
+        ReflectionMethod::invoke($object, $args)
+
+    have been changed to:
+
+        ReflectionClass::newInstance(...$args)
+        ReflectionFunction::invoke(...$args)
+        ReflectionMethod::invoke($object, ...$args)
+
+    Code that must be compatible with both PHP 7 and PHP 8 can use the following
+    signatures to be compatible with both versions:
+
+        ReflectionClass::newInstance($arg = null, ...$args)
+        ReflectionFunction::invoke($arg = null, ...$args)
+        ReflectionMethod::invoke($object, $arg = null, ...$args)
+
+  . The ReflectionType::__toString() method will now return a complete debug
+    representation of the type, and is no longer deprecated. In particular the
+    result will include a nullability indicator for nullable types. The format
+    of the return value is not stable and may change between PHP versions.
+  . Reflection export() methods have been removed.
+  . The following methods can now return information about default values of
+    parameters of internal functions:
+        ReflectionParameter::isDefaultValueAvailable()
+        ReflectionParameter::getDefaultValue()
+        ReflectionParameter::isDefaultValueConstant()
+        ReflectionParameter::getDefaultValueConstantName()
+  . ReflectionMethod::isConstructor() and ReflectionMethod::isDestructor() now
+    also return true for `__construct` and `__destruct` methods of interfaces.
+    Previously, this would only be true for methods of classes and traits.
+  . ReflectionType::isBuiltin() method has been moved to ReflectionNamedType.
+    ReflectionUnionType does not have it.
+
+- Sockets:
+  . The deprecated AI_IDN_ALLOW_UNASSIGNED and AI_IDN_USE_STD3_ASCII_RULES
+    flags for socket_addrinfo_lookup() have been removed.
+  . socket_create(), socket_create_listen(), socket_accept(),
+    socket_import_stream(), socket_addrinfo_connect(), socket_addrinfo_bind(),
+    and socket_wsaprotocol_info_import() will now return a Socket object rather
+    than a resource. Return value checks using is_resource() should be replaced
+    with checks for `false`.
+  . socket_addrinfo_lookup() will now return an array of AddressInfo objects
+    rather than resources.
+
+- SPL:
+  . SplFileObject::fgetss() has been removed.
+  . SplHeap::compare($a, $b) now specifies a method signature. Inheriting
+    classes implementing this method will now have to use a compatible
+    method signature.
+  . SplDoublyLinkedList::push() now returns void instead of true
+  . SplDoublyLinkedList::unshift() now returns void instead of true
+  . SplQueue::enqueue() now returns void instead of true
+  . spl_autoload_register() will now always throw a TypeError on invalid
+    arguments, therefore the second argument $do_throw is ignored and a
+    notice will be emitted if it is set to false.
+
+- Standard:
+  . assert() will no longer evaluate string arguments, instead they will be
+    treated like any other argument. assert($a == $b) should be used instead of
+    assert('$a == $b'). The assert.quiet_eval ini directive and
+    ASSERT_QUIET_EVAL constants have also been removed, as they would no longer
+    have any effect.
+  . parse_str() can no longer be used without specifying a result array.
+  . fgetss() has been removed.
+  . The string.strip_tags filter has been removed.
+  . The needle argument of strpos(), strrpos(), stripos(), strripos(), strstr(),
+    strchr(), strrchr(), and stristr() will now always be interpreted as a
+    string. Previously non-string needles were interpreted as an ASCII code
+    point. An explicit call to chr() can be used to restore the previous
+    behavior.
+  . The needle argument for strpos(), strrpos(), stripos(), strripos(),
+    strstr(), stristr() and strrchr() can now be empty.
+  . The length argument for substr(), substr_count(), substr_compare(), and
+    iconv_substr() can now be null. Null values will behave as if no length
+    argument was provided and will therefore return the remainder of the string
+    instead of an empty string.
+  . The length argument for array_splice() can now be null. Null values will
+    behave identically to omitting the argument, thus removing everything from
+    the 'offset' to the end of the array.
+  . The args argument of vsprintf(), vfprintf(), and vprintf() must now be an
+    array. Previously any type was accepted.
+  . The 'salt' option of password_hash() is no longer supported. If the 'salt'
+    option is used a warning is generated, the provided salt is ignored, and a
+    generated salt is used instead.
+  . The quotemeta() function will now return an empty string if an empty string
+    was passed. Previously false was returned.
+  . hebrevc() has been removed.
+  . convert_cyr_string() has been removed.
+  . money_format() has been removed.
+  . ezmlm_hash() has been removed.
+  . restore_include_path() has been removed.
+  . get_magic_quotes_gpc() and get_magic_quotes_gpc_runtime() has been removed.
+  . FILTER_SANITIZE_MAGIC_QUOTES has been removed.
+  . Calling implode() with parameters in a reverse order ($pieces, $glue) is no
+    longer supported.
+  . parse_url() will now distinguish absent and empty queries and fragments:
+
+        http://example.com/foo   => query = null, fragment = null
+        http://example.com/foo?  => query = "",   fragment = null
+        http://example.com/foo#  => query = null, fragment = ""
+        http://example.com/foo?# => query = "",   fragment = ""
+
+    Previously all cases resulted in query and fragment being null.
+  . var_dump() and debug_zval_dump() will now print floating-point numbers
+    using serialize_precision rather than precision. In a default configuration,
+    this means that floating-point numbers are now printed with full accuracy
+    by these debugging functions.
+  . If the array returned by __sleep() contains non-existing properties, these
+    are now silently ignored. Previously, such properties would have been
+    serialized as if they had the value NULL.
+  . The default locale on startup is now always "C". No locales are inherited
+    from the environment by default. Previously, LC_ALL was set to "C", while
+    LC_CTYPE was inherited from the environment. However, some functions did not
+    respect the inherited locale without an explicit setlocale() call. An
+    explicit setlocale() call is now always required if you wish to change any
+    locale component from the default.
+  . Removed deprecated DES fallback in crypt(). If an unknown salt format is
+    passed to crypt(), the function will fail with *0 instead of falling back
+    to a weak DES hash now.
+  . Specifying out of range rounds for sha256/sha526 crypt() will now fail with
+    *0 instead of clamping to the closest limit. This matches glibc behavior.
+  . The result of sorting functions may have changed, if the array contains
+    elements that compare as equal.
+  . Sort comparison functions that return true or false will now throw a
+    deprecation warning, and should be replaced with an implementation
+    that returns an integer less than, equal to, or greater than zero.
+
+        // Replace
+        usort($array, fn($a, $b) => $a > $b);
+        // With
+        usort($array, fn($a, $b) => $a <=> $b);
+
+  . Any functions accepting callbacks that are not explicitly specified to
+    accept parameters by reference will now warn if a callback with reference
+    parameters is used. Examples include array_filter() and array_reduce().
+    This was already the case for most, but not all, functions previously.
+  . The HTTP stream wrapper as used by functions like file_get_contents()
+    now advertises HTTP/1.1 rather than HTTP/1.0 by default. This does not
+    change the behavior of the client, but may cause servers to respond
+    differently. To retain the old behavior, set the 'protocol_version'
+    stream context option, e.g.
+
+        $ctx = stream_context_create(['http' => ['protocol_version' => '1.0']]);
+        echo file_get_contents('http://example.org', false, $ctx);
+
+- Sysvmsg:
+  . msg_get_queue() will now return an SysvMessageQueue object rather than a
+    resource. Return value checks using is_resource() should be replaced with
+    checks for `false`.
+
+- Sysvsem:
+  . sem_get() will now return an SysvSemaphore object rather than a resource.
+    Return value checks using is_resource() should be replaced with checks
+    for `false`.
+
+- Sysvshm:
+  . shm_attach() will now return an SysvSharedMemory object rather than a resource.
+    Return value checks using is_resource() should be replaced with checks
+    for `false`.
+
+- tidy:
+  . The $use_include_path parameter, which was not used internally, has been
+    removed from tidy_repair_string().
+
+- Tokenizer:
+  . T_COMMENT tokens will no longer include a trailing newline. The newline will
+    instead be part of a following T_WHITESPACE token. It should be noted that
+    T_COMMENT is not always followed by whitespace, it may also be followed by
+    T_CLOSE_TAG or end-of-file.
+  . Namespaced names are now represented using the T_NAME_QUALIFIED (Foo\Bar),
+    T_NAME_FULLY_QUALIFIED (\Foo\Bar) and T_NAME_RELATIVE (namespace\Foo\Bar)
+    tokens. T_NS_SEPARATOR is only used for standalone namespace separators,
+    and only syntactially valid in conjunction with group use declarations.
+    RFC: https://wiki.php.net/rfc/namespaced_names_as_token
+
+- XML:
+  . xml_parser_create(_ns) will now return an XmlParser object rather than a
+    resource. Return value checks using is_resource() should be replaced with
+    checks for `false`. The xml_parser_free() function no longer has an effect,
+    instead the XmlParser instance is automatically destroyed if it is no longer
+    referenced.
+
+- XMLWriter:
+  . The XMLWriter functions now accept and return, respectively, XMLWriter
+    objects instead of resources.
+
+- Zip:
+  . ZipArchive::OPSYS_Z_CPM has been removed (this name was a typo). Use
+    ZipArchive::OPSYS_CPM instead.
+
+- Zlib:
+  . gzgetss() has been removed.
+  . inflate_init() will now return an InflateContext object rather than a
+    resource. Return value checks using is_resource() should be replaced with
+    checks for `false`.
+  . deflate_init() will now return a DeflateContext object rather than a
+    resource. Return value checks using is_resource() should be replaced with
+    checks for `false`.
+
 ========================================
 2. New Features
 ========================================
 
+- Core:
+  . Added support for union types.
+    RFC: https://wiki.php.net/rfc/union_types_v2
+  . Added WeakMap.
+    RFC: https://wiki.php.net/rfc/weak_maps
+  . Added ValueError class.
+  . Any number of function parameters may now be replaced by a variadic
+    argument, as long as the types are compatible. For example, the following
+    code is now allowed:
+
+        class A {
+            public function method(int $many, string $parameters, $here) {}
+        }
+        class B extends A {
+            public function method(...$everything) {}
+        }
+  . "static" (as in "late static binding") can now be used as a return type:
+
+        class Test {
+            public function create(): static {
+                return new static();
+            }
+        }
+
+    RFC: https://wiki.php.net/rfc/static_return_type
+  . It is now possible to fetch the class name of an object using
+    `$object::class`. The result is the same as `get_class($object)`.
+    RFC: https://wiki.php.net/rfc/class_name_literal_on_object
+  . New and instanceof can now be used with arbitrary expressions, using
+    `new (expression)(...$args)` and `$obj instanceof (expression)`.
+    RFC: https://wiki.php.net/rfc/variable_syntax_tweaks
+  . Some consistency fixes to variable syntax have been applied, for example
+    writing `Foo::BAR::$baz` is now allowed.
+    RFC: https://wiki.php.net/rfc/variable_syntax_tweaks
+  . Added Stringable interface, which is automatically implemented if a class
+    defines a __toString() method.
+    RFC: https://wiki.php.net/rfc/stringable
+  . Traits can now define abstract private methods.
+    RFC: https://wiki.php.net/rfc/abstract_trait_method_validation
+  . `throw` can now be used as an expression.
+    RFC: https://wiki.php.net/rfc/throw_expression
+  . An optional trailing comma is now allowed in parameter lists.
+    RFC: https://wiki.php.net/rfc/trailing_comma_in_parameter_list
+  . It is now possible to write `catch (Exception)` to catch an exception
+    without storing it in a variable.
+    RFC: https://wiki.php.net/rfc/non-capturing_catches
+  . Added support for mixed type
+    RFC: https://wiki.php.net/rfc/mixed_type_v2
+  . Added support for Attributes
+    RFC: https://wiki.php.net/rfc/attributes_v2
+    RFC: https://wiki.php.net/rfc/attribute_amendments
+    RFC: https://wiki.php.net/rfc/shorter_attribute_syntax
+  . Added support for constructor property promotion (declaring properties in
+    the constructor signature).
+    RFC: https://wiki.php.net/rfc/constructor_promotion
+  . Added support for `match` expression.
+    RFC: https://wiki.php.net/rfc/match_expression_v2
+  . Private methods declared on a parent class no longer enforce any
+    inheritance rules on the methods of a child class. (with the exception of
+    final private constructors)
+    RFC: https://wiki.php.net/rfc/inheritance_private_methods
+  . Added support for nullsafe operator (`?->`).
+    RFC: https://wiki.php.net/rfc/nullsafe_operator
+  . Added support for named arguments.
+    RFC: https://wiki.php.net/rfc/named_params
+
+- Date:
+  . Added DateTime::createFromInterface() and
+    DateTimeImmutable::createFromInterface().
+  . Added the DateTime format specifier "p" which is the same as "P" but
+    returning "Z" for UTC.
+
+- Dom:
+  . Introduce DOMParentNode and DOMChildNode with new traversal and
+    manipulation APIs.
+    RFC: https://wiki.php.net/rfc/dom_living_standard_api
+
+- Enchant:
+  . enchant_dict_add()
+  . enchant_dict_is_added()
+  . LIBENCHANT_VERSION macro
+
+- FPM:
+  . Added a new option pm.status_listen that allows getting status from
+    different endpoint (e.g. port or UDS file) which is useful for getting
+    status when all children are busy with serving long running requests.
+
+- Hash:
+  . HashContext objects can now be serialized.
+
+- Opcache:
+  . If the opcache.record_warnings ini setting is enabled, opcache will record
+    compile-time warnings and replay them on the next include, even if it is
+    served from cache.
+
+- OpenSSL:
+  . Added Cryptographic Message Syntax (CMS) (RFC 5652) support composed of
+    functions for encryption, decryption, signing, verifying and reading. The
+    API is similar to the API for PKCS #7 functions with an addition of new
+    encoding constants: OPENSSL_ENCODING_DER, OPENSSL_ENCODING_SMIME and
+    OPENSSL_ENCODING_PEM.
+
+- Standard:
+  . printf() and friends now support the %h and %H format specifiers. These
+    are the same as %g and %G, but always use "." as the decimal separator,
+    rather than determining it through the LC_NUMERIC locale.
+  . printf() and friends now support using "*" as width or precision, in which
+    case the width/precision is passed as an argument to printf. This also
+    allows using precision -1 with %g, %G, %h and %H. For example, the following
+    code can be used to reproduce PHP's default floating point formatting:
+
+        printf("%.*H", (int) ini_get("precision"), $float);
+        printf("%.*H", (int) ini_get("serialize_precision"), $float);
+
+  . proc_open() now supports pseudo-terminal (PTY) descriptors. The following
+    attaches stdin, stdout and stderr to the same PTY:
+
+        $proc = proc_open($command, [['pty'], ['pty'], ['pty']], $pipes);
+
+  . proc_open() now supports socket pair descriptors. The following attaches
+    a distinct socket pair to stdin, stdout and stderr:
+
+        $proc = proc_open(
+            $command, [['socket'], ['socket'], ['socket']], $pipes);
+
+    Unlike pipes, sockets do not suffer from blocking I/O issues on Windows.
+    However, not all programs may work correctly with stdio sockets.
+  . Sorting functions are now stable, which means that equal-comparing elements
+    will retain their original order.
+    RFC: https://wiki.php.net/rfc/stable_sorting
+
+- Zip:
+  . Extension updated to version 1.19.0
+  . New ZipArchive::lastId property to get index value of last added entry.
+  . Error can be checked after an archive is closed using ZipArchive::status,
+    ZipArchive::statusSys properties or ZipArchive::getStatusString() method.
+  . The remove_path option of ZipArchive::addGlob() and ::addPattern() is now
+    treated as arbitrary string prefix (for consistency with the add_path
+    option), whereas formerly it was treated as directory name.
+  . Optional compression / encryption features are listed in phpinfo.
+
 ========================================
 3. Changes in SAPI modules
 ========================================
 
+- Apache:
+  . The PHP module has been renamed from php7_module to php_module.
+
+- CGI and FPM will now use CONTEXT_DOCUMENT_ROOT to scan for .user.ini files,
+  if it is defined. Otherwise, DOCUMENT_ROOT will be used as before. This
+  improves support for Apache mod_userdir and mod_alias.
+
 ========================================
 4. Deprecated Functionality
 ========================================
 
+- Core:
+  . Declaring a required parameter after an optional one is deprecated. As an
+    exception, declaring a parameter of the form "Type $param = null" before
+    a required one continues to be allowed, because this pattern was sometimes
+    used to achieve nullable types in older PHP versions.
+
+        function test($a = [], $b) {}       // Deprecated
+        function test(Foo $a = null, $b) {} // Allowed
+  . Calling get_defined_functions() with $exclude_disabled explicitly set to
+    false is deprecated. get_defined_functions() will never include disabled
+    functions.
+
+- Enchant:
+  . enchant_broker_set_dict_path and enchant_broker_get_dict_path
+    not available in libenchant < 1.5 nor in libenchant-2
+  . enchant_dict_add_to_personal, use enchant_dict_add instead
+  . enchant_dict_is_in_session, use enchant_dict_is_added instead
+  . enchant_broker_free and enchant_broker_free_dict, unset the object instead
+  . ENCHANT_MYSPELL and ENCHANT_ISPELL constants
+
+- LibXML:
+  . libxml_disable_entity_loader() has been deprecated. As libxml 2.9.0 is now
+    required, external entity loading is guaranteed to be disabled by default,
+    and this function is no longer needed to protect against XXE attacks.
+
+- PGSQL / PDO PGSQL:
+  . The constant PG_VERSION_STR has now the same value as PG_VERSION, and thus
+    is deprecated.
+
+- Zip:
+  . Using empty file as ZipArchive is deprecated. Libzip 1.6.0
+    do not accept empty files as valid zip archives any longer.
+    Existing workaround will be removed in next version.
+  . The procedural API of Zip is deprecated. Use ZipArchive instead.
+
+- Reflection:
+  . ReflectionFunction::isDisabled() is deprecated, as it is no longer possible
+    to create a ReflectionFunction for a disabled function. This method now
+    always returns false.
+  . ReflectionParameter::getClass(), ReflectionParameter::isArray(), and
+    ReflectionParameter::isCallable() are deprecated.
+    ReflectionParameter::getType() and the ReflectionType APIs should be used
+    instead.
+
 ========================================
 5. Changed Functions
 ========================================
 
+- Reflection:
+  . ReflectionClass::getConstants and ReflectionClass::getReflectionConstants results
+    can be now filtered via a new parameter `$filter`. 3 new constants were added to
+    be used with it:
+
+      ReflectionClassConstant::IS_PUBLIC
+      ReflectionClassConstant::IS_PROTECTED
+      ReflectionClassConstant::IS_PRIVATE
+
+- Zip
+ . ZipArchive::addGlob and ZipArchive::addPattern methods accept more
+   values in the "options" array argument:
+   . flags
+   . comp_method
+   . comp_flags
+   . env_method
+   . enc_password
+ . ZipArchive::addEmptyDir, ZipArchive::addFile and aZipArchive::addFromString
+   methods have a new "flags" argument. This allows managing name encoding
+   (ZipArchive::FL_ENC_*) and entry replacement (ZipArchive::FL_OVERWRITE)
+ . ZipArchive::extractTo now restore file modification time.
+
 ========================================
 6. New Functions
 ========================================
 
+- Core:
+  . Added get_resource_id($resource) function, which returns the same value as
+    (int) $resource. It provides the same functionality under a clearer API.
+
+- LDAP:
+  . Added ldap_count_references(), which returns the number of reference
+    messages in a search result.
+
+- OpenSSL:
+  . Added openssl_cms_encrypt() encrypts the message in the file with the
+    certificates and outputs the result to the supplied file.
+  . Added openssl_cms_decrypt() that decrypts the S/MIME message in the file
+    and outputs the results to the supplied file.
+  . Added openssl_cms_read() that exports the CMS file to an array of PEM
+    certificates.
+  . Added openssl_cms_sign() that signs the MIME message in the file with
+    a cert and key and output the result to the supplied file.
+  . Added openssl_cms_verify() that verifies that the data block is intact,
+    the signer is who they say they are, and returns the certs of the signers.
+
+- PCRE:
+  . Added preg_last_error_msg(), which returns a human-readable message for
+    the last PCRE error. It complements preg_last_error(), which returns an
+    integer enum instead.
+
+- SQLite3:
+  . Add SQLite3::setAuthorizer() and respective class constants to set a
+    userland callback that will be used to authorize or not an action on the
+    database.
+    PR: https://github.com/php/php-src/pull/4797
+
+- Standard:
+  . Added
+
+        str_contains(string $haystack, string $needle): bool
+        str_starts_with(string $haystack, string $needle): bool
+        str_ends_with(string $haystack, string $needle): bool
+
+    functions, which check whether $haystack contains, starts with or ends with
+    $needle.
+    RFC: https://wiki.php.net/rfc/str_contains
+    RFC: https://wiki.php.net/rfc/add_str_starts_with_and_ends_with_functions
+  . Added fdiv() function, which performs a floating-point division under
+    IEEE 754 semantics. Division by zero is considered well-defined and
+    will return one of Inf, -Inf or NaN.
+  . Added get_debug_type() function, which returns a type useful for error
+    messages. Unlike gettype(), it uses canonical type names, returns class
+    names for objects, and indicates the resource type for resources.
+    RFC: https://wiki.php.net/rfc/get_debug_type
+
+- Zip:
+  . ZipArchive::setMtimeName and ZipArchive::setMtimeIndex to set the
+    modification time of an entry.
+  . ZipArchive::setProgressCallback to provide updates during archive close.
+  . ZipArchive::setCancelCallback to allow cancellation during archive close.
+  . ZipArchive::replaceFile to replace an entry content.
+  . ZipArchive::isCompressionMethodSupported to check optional compression
+    features.
+  . ZipArchive::isEncryptionMethodSupported to check optional encryption
+    features.
+
 ========================================
 7. New Classes and Interfaces
 ========================================
 
+- Tokenizer:
+  . The new PhpToken class adds an object-based interface to the tokenizer.
+    It provides a more uniform and ergonomic representation, while being more
+    memory efficient and faster.
+    RFC: https://wiki.php.net/rfc/token_as_object
+
 ========================================
 8. Removed Extensions and SAPIs
 ========================================
 
+- XML-RPC:
+  . The xmlrpc extension has been unbundled and moved to PECL.
+    RFC: https://wiki.php.net/rfc/unbundle_xmlprc
+
 ========================================
 9. Other Changes to Extensions
 ========================================
 
+- CURL:
+  . The CURL extension now requires at least libcurl 7.29.0.
+  . curl_init() will now return a CurlHandle object rather than a resource.
+    Return value checks using is_resource() should be replaced with
+    checks for `false`. The curl_close() function no longer has an effect,
+    instead the CurlHandle instance is automatically destroyed if it is no
+    longer referenced.
+  . curl_multi_init() will now return a CurlMultiHandle object rather than a
+    resource. Return value checks using is_resource() should be replaced with
+    checks for `false`. The curl_multi_close() function no longer has an effect,
+    instead the CurlMultiHandle instance is automatically destroyed if it is no
+    longer referenced.
+  . curl_share_init() will now return a CurlShareHandle object rather than a
+    resource. Return value checks using is_resource() should be replaced with
+    checks for `false`. The curl_share_close() function no longer has an effect,
+    instead the CurlShareHandle instance is automatically destroyed if it is no
+    longer referenced.
+  . The deprecated parameter `$version` of curl_version() has been removed.
+
+- Date:
+  . DatePeriod now implements IteratorAggregate (instead of Traversable).
+
+- DOM:
+  . DOMNamedNodeMap now implements IteratorAggregate (instead of Traversable).
+  . DOMNodeList now implements IteratorAggregate (instead of Traversable).
+
+- Intl:
+  . IntlBreakIterator now implements IteratorAggregate (instead of Traversable).
+  . ResourceBundle now implements IteratorAggregate (instead of Traversable).
+
+- Enchant:
+  . The enchant extension now uses libenchant-2 by default when available.
+    libenchant version 1 is still supported but is deprecated and could
+    be removed in the future.
+
+- GD:
+  . The $num_points parameter of imagepolygon(), imageopenpolygon() and
+    imagefilledpolygon() is now optional, i.e. these functions may be called
+    with either 3 or 4 arguments. If the arguments is omitted, it is calculated
+    as count($points)/2.
+  . The function imagegetinterpolation() to get the current interpolation method
+    has been added.
+
+- JSON:
+  . The JSON extension cannot be disabled anymore and is always an integral part
+    of any PHP build, similar to the date extension.
+
+- MBString:
+  . The Unicode data tables have been updated to version 13.0.0.
+
+- PDO:
+  . PDOStatement now implements IteratorAggregate (instead of Traversable).
+
+- LibXML:
+  . The minimum required libxml version is now 2.9.0. This means that external
+    entity loading is now guaranteed to be disabled by default, and no extra
+    steps need to be taken to protect against XXE attacks.
+
+- MySQLi / PDO MySQL:
+  . When mysqlnd is not used (which is the default and recommended option),
+    the minimum supported libmysqlclient version is now 5.1.
+  . mysqli_result now implements IteratorAggregate (instead of Traversable).
+
+- PGSQL / PDO PGSQL:
+  . The PGSQL and PDO PGSQL extensions now require at least libpq 9.1.
+
+- Readline:
+  . Calling readline_completion_function() before the interactive prompt starts
+    (e.g. in auto_prepend_file) will now override the default interactive prompt
+	completion function. Previously, readline_completion_function() only worked
+	when called after starting the interactive prompt.
+
+- SimpleXML:
+  . SimpleXMLElement now implements RecursiveIterator and absorbed the
+    functionality of SimpleXMLIterator. SimpleXMLIterator is an empty extension
+    of SimpleXMLElement.
+
+- Shmop:
+  . shmop_open() will now return a Shmop object rather than a resource. Return
+    value checks using is_resource() should be replaced with checks for `false`.
+    The shmop_close() function no longer has an effect, and is deprecated;
+    instead the Shmop instance is automatically destroyed if it is no longer
+    referenced.
+
 ========================================
 10. New Global Constants
 ========================================
 
+- Filter:
+  . FILTER_VALIDATE_BOOL has been added as an alias for FILTER_VALIDATE_BOOLEAN.
+    The new name is preferred, as it uses the canonical type name.
+
 ========================================
 11. Changes to INI File Handling
 ========================================
 
+- zend.exception_string_param_max_len
+  . New INI directive to set the maximum string length in an argument of a
+    stringified stack strace.
+
 ========================================
 12. Windows Support
 ========================================
 
+- Standard:
+  . Program execution functions (proc_open(), exec(), popen() etc.) using the
+    shell now consistently execute `%comspec% /s /c "$commandline"`, which has
+    the same effect as executing `$commandline` (without additional quotes).
+
+- GD:
+  . php_gd2.dll has been renamed to php_gd.dll.
+
+- php-test-pack:
+  . The test runner has been renamed from run-test.php to run-tests.php, to
+    match its name in php-src.
+
 ========================================
 13. Other Changes
 ========================================
 
+- EBCDIC targets are no longer supported, though it's unlikely that they were
+  still working in the first place.
+
 ========================================
 14. Performance Improvements
 ========================================
+
+- A Just-In-Time (JIT) compiler has been added to the opcache extension.
+- array_slice() on an array without gaps will no longer scan the whole array to
+  find the start offset. This may significantly reduce the runtime of the
+  function with large offsets and small lengths.
+- strtolower() now uses a SIMD implementation when using the "C" LC_CTYPE
+  locale (which is the default).