Php/docs/migration52.incompatible
Backward Incompatible Changes
Although most existing PHP 5 code should work without changes, you should pay attention to the following backward incompatible changes:
-
getrusage() returns
null
when passed incompatible arguments as of PHP 5.2.1. -
ZipArchive::setCommentName()
returns
true
on success as of PHP 5.2.1. -
ZipArchive::setCommentIndex()
returns
true
on success as of PHP 5.2.1. - SplFileObject::getFilename() returns the filename, not relative/path/to/file, as of PHP 5.2.1.
-
Changed priority of
PHPRC
environment variable on Win32 ThePHPRC
environment variable now takes priority over the path stored in the Windows registry. -
CLI SAPI no longer checks cwd for
php.ini
or thephp-cli.ini
file In PHP 5.1.x an undocumented feature was added that made the CLI binary check the current working directory for a PHP configuration file, potentially leading to unpredictable behavior if an unexpected configuration file were read. This functionality was removed in 5.2.0, and PHP will no longer search CWD for the presence ofphp.ini
orphp-cli.ini
files. See also the command line section of the manual. -
Added a warning when performing modulus 0 operations
In earlier versions of PHP, performing integer % 0 did not emit any
warning messages, instead returning an unexpected return value of
false
. As of PHP 5.2.0, this operation will emit anE_WARNING
, as is the case in all other instances where division by zero is performed.<?phpprint 10 % 0;/* Warning: Division by zero in filename on line n */?>
-
Changed __toString() to be called wherever
applicable.
The magic method __toString() will now be called
in a string context, that is, anywhere an object is used as a
string.
The fallback of returning a string that contains the
object identifier was dropped in PHP 5.2.0. It became
problematic because an object identifier cannot be considered
unique. This change will mean that your application is flawed if you
have relied on the object identifier as a return value. An attempt
to use that value as a string will now result in a catchable fatal
error.
<?phpclass foo {}$foo = new foo;print $foo;/* Catchable fatal error: Object of class foo could not be converted to string in filename on line n */?>
Even with __toString(), objects cannot be used as array indices or keys. We may add built-in hash support for this at a later date, but as of PHP 5.2.x you will need to either provide your own hashing or use the new SPL function spl_object_hash(). Exceptions can not be thrown from __toString() methods.
<?phpclass foo { public function __toString() { throw new Exception; }}try { print new foo; /* Fatal error: Method foo::__toString() must not throw an exception in filename on line n */} catch(Exception $e) {}?>
-
Dropped abstract static class functions.
Due to an oversight, PHP 5.0.x and 5.1.x allowed abstract static
functions in classes. As of PHP 5.2.x, only interfaces can have them.
<?phpabstract class foo { abstract static function bar(); /* Strict Standards: Static function foo::bar() should not be abstract in filename on line n */}?>
- Oracle extension requires at least Oracle 10 on Windows.
-
Added RFC2397 (
data:
stream) support. The introduction of the 'data' URL scheme has the potential to lead to a change of behavior under Windows. If you are working with a NTFS file system and making use of meta streams in your application, and if you just happen to be using a file with the name 'data:' that is accessed without any path information - it won't work any more. The fix is to use the 'file:' protocol when accessing it. See also » RFC 2397<?php/* when allow_url_include is OFF (default) */include "data:;base64,PD9waHAgcGhwaW5mbygpOz8+";/* Warning: include(): URL file-access is disabled in the server configuration in filename on line n */?>
-
Regression in
glob()
patterns In version 5.2.4 a security fix caused a regression for patterns of the form "/foo/*/bar/*". Since version 5.2.5 instead of raising a warning theglob()
function will returnfalse
whenopenbase_dir
restrictions are violated.