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

From: robin at ambitionally dot com Operating system: Windows, Linux PHP version: 7.1.9 Package: Class/Object related Bug Type: Bug Bug description:Changing array entry including &$this causes warning with call_user_func_array Description: ------------ When modifying an argument array that includes an entry for &$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 bug report at https://bugs.php.net/bug.php?id=75148&edit=1 -- Try a snapshot (PHP 5.4): https://bugs.php.net/fix.php?id=75148&r=trysnapshot54 Try a snapshot (PHP 5.5): https://bugs.php.net/fix.php?id=75148&r=trysnapshot55 Try a snapshot (trunk): https://bugs.php.net/fix.php?id=75148&r=trysnapshottrunk Fixed in SVN: https://bugs.php.net/fix.php?id=75148&r=fixed Fixed in release: https://bugs.php.net/fix.php?id=75148&r=alreadyfixed Need backtrace: https://bugs.php.net/fix.php?id=75148&r=needtrace Need Reproduce Script: https://bugs.php.net/fix.php?id=75148&r=needscript Try newer version: https://bugs.php.net/fix.php?id=75148&r=oldversion Not developer issue: https://bugs.php.net/fix.php?id=75148&r=support Expected behavior: https://bugs.php.net/fix.php?id=75148&r=notwrong Not enough info: https://bugs.php.net/fix.php?id=75148&r=notenoughinfo Submitted twice: https://bugs.php.net/fix.php?id=75148&r=submittedtwice register_globals: https://bugs.php.net/fix.php?id=75148&r=globals PHP 4 support discontinued: https://bugs.php.net/fix.php?id=75148&r=php4 Daylight Savings: https://bugs.php.net/fix.php?id=75148&r=dst IIS Stability: https://bugs.php.net/fix.php?id=75148&r=isapi Install GNU Sed: https://bugs.php.net/fix.php?id=75148&r=gnused Floating point limitations: https://bugs.php.net/fix.php?id=75148&r=float No Zend Extensions: https://bugs.php.net/fix.php?id=75148&r=nozend MySQL Configuration Error: https://bugs.php.net/fix.php?id=75148&r=mysqlcfg