Bug #75148 [Opn]: Changing array entry including &$this causes warning with call_user_func_array

Edit report at https://bugs.php.net/bug.php?id=75148&edit=1 ID: 75148 Updated by: cmb@php.net Reported by: robin at ambitionally dot com Summary: Changing array entry including &$this causes warning with call_user_func_array Status: Open Type: Bug Package: Scripting Engine problem Operating System: Windows, Linux PHP Version: 7.1.9 Block user comment: N Private report: N New Comment: I think this is related to the changes to call_user_func() handling of reference arguments[1], and likely something that won't be fixed. Use variable functions and the splat operator instead[2]. [1] <https://www.php.net/manual/en/migration71.incompatible.php#migration71.incompatible.call_user_func-with-ref-args> [2] <https://3v4l.org/MDLLi> Previous Comments: ------------------------------------------------------------------------ [2017-09-01 21:54:30] robin at ambitionally dot com Description: ------------ When modifying an argument array that includes an entry for &$this, the assignment operation seems to de-reference the &$this argument. As shown in the test script, line 6 and line 8 are identical, and line 7 assigns the same value to index [0] of the array. The issue is specific to PHP 7.1 (I have tested with 7.1.8 and 7.1.9), but it does not appear in PHP 7.0. var_dump before and after the assignment operation has the same printout. There is a difference in var_dump output between PHP 7.0 and 7.1. In 7.1, the var_dump output is missing the "&" for array entry [1], while the "&" symbol is present in PHP 7.0. This issue causes problems for WordPress sites, as it uses similar logic when running filters (WP_Hook::apply_filters). Test script: --------------- <?php function test_call($first, &$a) { echo '<div>here</div>'; } function test_warning($args) { call_user_func_array( 'test_call', $args ); // this line works $args[ 0 ] = 1; call_user_func_array( 'test_call', $args ); // this line causes error } class TestWarningClass{ function __construct() { $args = array( 1, &$this ); test_warning($args); } } $test = new TestWarningClass; Expected result: ---------------- No warning. Two lines of "here" are printed. Actual result: -------------- Warning: Parameter 2 to test_call() expected to be a reference, value given ------------------------------------------------------------------------ -- Edit this bug report at https://bugs.php.net/bug.php?id=75148&edit=1