Bug #80914 [Com]: function_exists is now case-sensitive for aliases
Edit report at https://bugs.php.net/bug.php?id=80914&edit=1
ID: 80914
Comment by: egegeg dot egeez at fff dot ff
Reported by: chris at vendiadvertising dot com
Summary: function_exists is now case-sensitive for aliases
Status: Open
Type: Bug
Package: *General Issues
Operating System: All
PHP Version: 8.0.3
Block user comment: N
Private report: N
New Comment:
functions in php are generally case-insensitive and every place where they are not is and was a bug
by definition - so this is a bugfix and not a bug
writing plain functions without a prefix is bad coding style anyways because you never know if a
future version brings a native function with the same name but different semantics
calling a function identical as a builtin but with different case is asking for troubles no matter
what
Previous Comments:
------------------------------------------------------------------------
[2021-03-29 14:45:59] chris at vendiadvertising dot com
Description:
------------
Prior to PHP 8, a function could use the same name as a built-in function's alias as long as it
changed the case. For example, the built-in function dir has an internal alias of getdir, and
user-land code could create a function called getDir without issue. As of PHP 8, doing so will raise
a Fatal error: Cannot redeclare xyz.
https://3v4l.org/hdHSS
This was originally noted on SO https://stackoverflow.com/q/66854655/231316
It appears that Bug #79382 (Cannot redeclare disabled function) was fixed in https://github.com/php/php-src/commit/53eee290b6f5ca531aef19885a392c939013ce36.
That fix uses a simple lower-case lookup of the provided function's name.
To be clear, overriding a built-in function, alias or not, is probably not a good idea, and I
don't know if this should be fixed. But it is an unexpected breaking change for legacy code and
it should at least be documented.
Test script:
---------------
var_dump(function_exists('getDir'));
Expected result:
----------------
In PHP prior to 8, the check returned false.
Actual result:
--------------
Starting with PHP 8 this returns true
------------------------------------------------------------------------
--
Edit this bug report at https://bugs.php.net/bug.php?id=80914&edit=1
Thread (8 messages)