Override construct function with optional argument should not produce fatal error
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Nobody has claimed this yet.
Bug
Status: Needs Triage
- Dominant language
- C
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Description
Description
The following code:
<?php
interface MyInterface1 { public function __construct(?string $name = null); }
interface MyInterface2 { public function __construct(?string $name = null, ?int $id = null); }
interface MyInterface3 extends MyInterface1, MyInterface2 { }
Resulted in this output:
PHP Fatal error: Declaration of MyInterface1::__construct(?string $name = null) must be compatible with MyInterface2::__construct(?string $name = null, ?int $id = null) in php shell code on line 1
But I expected no error and the following code works as expected:
<?php
interface MyInterface1 { public function __construct(?string $name = null); }
interface MyInterface2 { public function __construct(?string $name = null, ?int $id = null); }
interface MyInterface4 extends MyInterface2, MyInterface1 { }
PHP Version
PHP 8.4.24 (cli) (built: Jul 30 2026 15:23:13) (NTS)
Copyright (c) The PHP Group
Built by Ubuntu
Zend Engine v4.4.24, Copyright (c) Zend Technologies
with Zend OPcache v8.4.24, Copyright (c), by Zend Technologies
Operating System
Ubuntu 24.04.4 LTS
Contributor guide
First steps
- Read the whole issue, then the project's contributing guide.
- Comment on the issue to say you are picking it up — it saves two people doing the same work.
- Fork the repository and make your change on a branch.
- Open a pull request that references the issue number.
Research direction
Reproduce the two interface-inheritance snippets in PHP 8.4.24, comparing the parent-interface order and the resulting constructor compatibility error. Start by tracing the engine path that validates inherited interface methods; done means both declaration orders behave consistently without the reported fatal error, with a regression test covering the case.
Written by the indexing model from the issue text.
Assessment
- Tech stack
- php
- Domain
- compilers
- Issue type
- Bug
- Difficulty
- 4/5
- Estimated time
- 3-5 days
- Activity status
- Active
- Clarity
- Mostly clear
- Newbie friendliness
- 48/100