UPGRADING

PHP 8.4 UPGRADE NOTES

1. Backward Incompatible Changes
2. New Features
3. Changes in SAPI modules
4. Deprecated Functionality
5. Changed Functions
6. New Functions
7. New Classes and Interfaces
8. Removed Extensions and SAPIs
9. Other Changes to Extensions
10. New Global Constants
11. Changes to INI File Handling
12. Windows Support
13. Other Changes
14. Performance Improvements

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1. Backward Incompatible Changes
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- DOM:
  . New methods and constants were added to some DOM classes. If you inherit
    from these and you happen to have a method or property with the same name,
    you might encounter errors if the declaration is incompatible.
    Consult sections 2. New Features and 6. New Functions for a list of
    newly implemented methods and constants.

- PDO_PGSQL:
  . The DSN's credentials, when set, are given priority over their PDO
    constructor counterparts, being closer to the documentation states.

- PCNTL:
  . The functions pcntl_sigprocmask(), pcntl_sigwaitinfo() and
    pcntl_sigtimedwait() now throw:
    - A ValueError if the $signals array is empty (except for
      pcntl_sigprocmask() if the $mode is SIG_SETMASK).
    - A TypeError if a value of the $signals array is not an integer
    - A ValueError if a value of the $signals array is not a valid signal number
    Moreover, those functions now always return false on failure.
    In some case previously it could return the value -1.
  . The function pcntl_sigprocmask() will also now throw:
    - A ValueError if $mode is not one of SIG_BLOCK, SIG_UNBLOCK, or SIG_SETMASK
  . The function pcntl_sigtimedwait() will also now throw:
    - A ValueError if $seconds is less than 0
    - A ValueError if $nanoseconds is less than 0 or greater than 1e9
    - A ValueError if both $seconds and $nanoseconds are 0

- SimpleXML:
  . Get methods called, or casting to a string on a SimpleXMLElement will no
    longer implicitly reset the iterator data, unless explicitly rewound.
    For example, casting an element to a string within a foreach loop would
    cause an infinite loop because it destroyed the current iterator data.
    This is no longer the case as a consequence of the bugfixes for GH-12192,
    GH-12208, #55098.

- SPL:
  . Out of bounds accesses in SplFixedArray now throw an exception of type
    OutOfBoundsException instead of RuntimeException. As OutOfBoundsException
    is a child class of RuntimeException, code that uses RuntimeException
    continues to function.

- Standard:
  . round() now validates the value of the $mode parameter and throws a ValueError
    for invalid modes. Previously invalid modes would have been interpreted as
    PHP_ROUND_HALF_UP.
  . strcspn() with empty $characters now returns the length of the string instead
    of incorrectly stopping at the first NUL character. See GH-12592.

- XML:
  . The xml_set_*_handler() functions now declare and check for an effective
    signature of callable|string|null for the $handler parameters.
    Moreover, values of type string that correspond to method names,
    of object set with xml_set_object() are now checked to see if the method
    exists on the class of the previously passed object.
    This means that xml_set_object() must now always be called prior to setting
    method names as callables.
    Passing an empty string to disable the handler is still allowed,
    but not recommended.

- XSL:
  . XSLTProcessor::setParameter() will now throw a ValueError when its arguments
    contain null bytes. This never actually worked correctly in the first place,
    which is why it throws an exception nowadays.

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2. New Features
========================================

- DOM:
  . Added constant DOMNode::DOCUMENT_POSITION_DISCONNECTED.
  . Added constant DOMNode::DOCUMENT_POSITION_PRECEDING.
  . Added constant DOMNode::DOCUMENT_POSITION_FOLLOWING.
  . Added constant DOMNode::DOCUMENT_POSITION_CONTAINS.
  . Added constant DOMNode::DOCUMENT_POSITION_CONTAINED_BY.
  . Added constant DOMNode::DOCUMENT_POSITION_IMPLEMENTATION_SPECIFIC.
  . Implemented DOM HTML5 parsing and serialization.
    RFC: https://wiki.php.net/rfc/domdocument_html5_parser.
    This RFC adds the new DOM namespace along with class and constant aliases.
    There are two new classes to handle HTML and XML documents:
    DOM\HTMLDocument and DOM\XMLDocument.
    These classes provide a cleaner API to handle HTML and XML documents.
    Furthermore, the DOM\HTMLDocument class implements spec-compliant HTML5
    parsing and serialization.

- Phar:
  . Added support for the unix timestamp extension for zip archives.

- POSIX:
  . Added constant POSIX_SC_CHILD_MAX
  . Added constant POSIX_SC_CLK_TCK

- SOAP:
  . Added support for clark notation for namespaces in class map.
    It is now possible to specify entries in a class map with clark notation
    to resolve a type with a specific namespace to a specific class.
    For example: '{http://example.com}foo' => 'FooClass'.

- XSL:
  . It is now possible to use parameters that contain both single and double
    quotes.

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3. Changes in SAPI modules
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4. Deprecated Functionality
========================================

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5. Changed Functions
========================================

- MBString:
  . The behavior of mb_strcut is more consistent now on invalid UTF-8 and UTF-16
    strings. (For valid UTF-8 and UTF-16 strings, there is no change.)

- PGSQL:
  . pg_select, the conditions arguments accepts an empty array and is optional.

- Standard:
  . The internal implementation for rounding to integers has been rewritten
    to be easier to verify for correctness and to be easier to maintain.
    Some rounding bugs have been fixed as a result of the rewrite. For
    example previously rounding 0.49999999999999994 to the nearest integer
    would have resulted in 1.0 instead of the correct result 0.0. Additional
    inputs might also be affected and result in different outputs compared to
    earlier PHP versions.
  . The default value of the 'cost' option for PASSWORD_BCRYPT for password_hash()
    has been increased from '10' to '12'.

    RFC: https://wiki.php.net/rfc/bcrypt_cost_2023

========================================
6. New Functions
========================================

- DOM:
  . Added DOMNode::compareDocumentPosition().

- MBString:
  . Added mb_trim, mb_ltrim and mb_rtrim functions.
    RFC: https://wiki.php.net/rfc/mb_trim

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7. New Classes and Interfaces
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8. Removed Extensions and SAPIs
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9. Other Changes to Extensions
========================================

- Intl:
  . The class constants are typed now.

- PDO:
  . The class constants are typed now.

- Reflection:
  . The class constants are typed now.

- Spl:
  . The class constants are typed now.

- Sqlite:
  . The class constants are typed now.

- XSL:
  . The typed properties XSLTProcessor::$cloneDocument and
    XSLTProcessor::$doXInclude are now declared.

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10. New Global Constants
========================================

- Intl:
  . The IntlDateFormatter class exposes now the new PATTERN constant
    reflecting udat api's UDAT_PATTERN.

- XML:
  . Added XML_OPTION_PARSE_HUGE to allow large inputs in xml_parse and
    xml_parse_into_struct.
    RFC: https://wiki.php.net/rfc/xml_option_parse_huge.

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11. Changes to INI File Handling
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12. Windows Support
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13. Other Changes
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14. Performance Improvements
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* The performance of DOMNode::C14N() is greatly improved for the case without
  an xpath query. This can give a time improvement of easily two order of
  magnitude for documents with tens of thousands of nodes.

* The performance of strspn() and strcspn() is greatly improved.
  They now run in linear time instead of being bounded by quadratic time.

* mb_strcut() is much faster now for UTF-8 and UTF-16 strings.

* Looking up mbstring encoding names is much faster now.

* The performance of converting SJIS-win to unicode is greatly improved.

* get_browser() is much faster now, up to 1.5x - 2.5x for some test cases.