Bug #79393 [Opn->Ver]: Null coalescing operator failing with SplFixedArray

Edit report at https://bugs.php.net/bug.php?id=79393&edit=1 ID: 79393 Updated by: cmb@php.net Reported by: julien dot falque at gmail dot com Summary: Null coalescing operator failing with SplFixedArray -Status: Open +Status: Verified Type: Bug Package: SPL related Operating System: Linux PHP Version: 7.4.4RC1 -Assigned To: +Assigned To: cmb Block user comment: N Private report: N Previous Comments: ------------------------------------------------------------------------ [2020-03-18 12:59:31] julien dot falque at gmail dot com Description: ------------ This is probably related to https://bugs.php.net/bug.php?id=74478. Using null coalescing operation on an index that does not exist in an SplFixedArray triggers an exception (Index invalid or out of range) while doing the same with isset() works as expected. See the following snippets: * with isset(): https://3v4l.org/s79uA * with null coalescing operator: https://3v4l.org/ucSbZ For some reason, using a class that extends SplFixedArray and overrides method offsetExists() works: https://3v4l.org/5ohF1. Test script: --------------- <?php $foo = new SplFixedArray(2); $foo[0] = 'bar1'; $foo[1] = 'bar2'; var_dump($foo[0] ?? null); var_dump($foo[1] ?? null); var_dump($foo[2] ?? null); Expected result: ---------------- string(4) "bar1" string(4) "bar2" NULL Actual result: -------------- string(4) "bar1" string(4) "bar2" Fatal error: Uncaught RuntimeException: Index invalid or out of range in /in/ucSbZ:9 Stack trace: #0 {main} thrown in /in/ucSbZ on line 9 ------------------------------------------------------------------------ -- Edit this bug report at https://bugs.php.net/bug.php?id=79393&edit=1