Assertion failure when error handler throws when accessing a deprecated constant

[dktapps]

Description

The following code:

<?php

final class ErrorTypeToStringMap{
	private const ERROR_STRINGS = [
		E_STRICT => "E_STRICT",
	];

	private function __construct(){

	}

	public static function get(int $errorType) : string{
		if(!isset(self::ERROR_STRINGS[$errorType])){
			throw new \InvalidArgumentException("Invalid error type $errorType");
		}

		return self::ERROR_STRINGS[$errorType];
	}
}

set_error_handler(function(int $severity, string $message, string $file, int $line): bool{
	throw new \ErrorException($message, 0, $severity, $file, $line);
});

var_dump(ErrorTypeToStringMap::get(E_ERROR));

Resulted in this output:

Assertion failed: !(((zend_executor_globals *) (((char*) _tsrm_ls_cache)+(executor_globals_offset)))->exception), file C:\pocketmine-php-8.4.12-debug\php-src\Zend\zend_vm_execute.h, line 35382

But I expected this output instead:

Fatal error: Uncaught InvalidArgumentException: Invalid error type 1 in C:\Users\dylan-work\Documents\projects\pocketmine-mp\stable\test4.php:16
Stack trace:
#0 C:\Users\dylan-work\Documents\projects\pocketmine-mp\stable\test4.php(30): ErrorTypeToStringMap::get(1)
#1 {main}
  thrown in C:\Users\dylan-work\Documents\projects\pocketmine-mp\stable\test4.php on line 16

PHP Version

PHP 8.4.12 (cli) (built: Sep  5 2025 15:31:51) (ZTS Visual C++ 2022 x64 DEBUG)
Copyright (c) The PHP Group
Zend Engine v4.4.12, Copyright (c) Zend Technologies
    with Zend OPcache v8.4.12, Copyright (c), by Zend Technologies

Operating System

Windows 11

[nielsdos]

Right, as this is now a deprecated constant this triggers the error handler which triggers an exception.
Likely reproducible on lower branches too if you have a deprecated constant there. I'll make a quick look.

[nielsdos]

This works (on master), but I need to reduce the test case for 8.3 etc

diff --git a/Zend/zend_API.c b/Zend/zend_API.c
index fa5365b776d..5f87d54c1a8 100644
--- a/Zend/zend_API.c
+++ b/Zend/zend_API.c
@@ -1520,6 +1520,8 @@ ZEND_API zend_result zend_update_class_constant(zend_class_constant *c, const ze
 	zval_ptr_dtor(&c->value);
 	ZVAL_COPY_VALUE(&c->value, &tmp);
 
+	/* may not return SUCCESS in case of an exception, should've returned FAILURE in zval_update_constant_ex! */
+	ZEND_ASSERT(!EG(exception));
 	return SUCCESS;
 }
 
diff --git a/Zend/zend_constants.c b/Zend/zend_constants.c
index efdcb905fd7..a18c393be7f 100644
--- a/Zend/zend_constants.c
+++ b/Zend/zend_constants.c
@@ -487,6 +487,9 @@ ZEND_API zval *zend_get_constant_ex(zend_string *cname, zend_class_entry *scope,
 			CONST_PROTECT_RECURSION(c);
 			zend_deprecated_constant(c, c->name);
 			CONST_UNPROTECT_RECURSION(c);
+			if (UNEXPECTED(EG(exception))) {
+				return NULL;
+			}
 		}
 	}
 	return &c->value;

[nielsdos]

Thanks for the report, PR is up for 8.3+.