php-src/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.

- 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.

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

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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.

- 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
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- 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

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6. New Functions
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- DOM:
  . Added DOMNode::compareDocumentPosition().

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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
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- 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.

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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() is greatly improved. It now runs in linear time
  instead of being bounded by quadratic time.

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