From 8feaca536906a4f68e5d68df48b1d69e998fcf41 Mon Sep 17 00:00:00 2001
From: PurHur <PurHur@users.noreply.github.com>
Date: Tue, 18 Aug 2026 02:26:27 +0000
Subject: [PATCH] Add compliance guard for magic property pre/post dec (#32014)

Repro scripts and VM/JIT .phpt lock in silent __get/__set behavior for
--$obj->n and $obj->n-- covered by the #31992 inc/dec guard in lib/VM.php
and lib/JIT.php; register inc/dec suites in phpunit.xml.dist.

Co-authored-by: Cursor <cursoragent@cursor.com>
---
 phpunit.xml.dist                              |  4 +++
 .../MagicPropDecNoUndefWarnJITTest.php        | 29 +++++++++++++++++++
 .../MagicPropDecNoUndefWarnVMTest.php         | 29 +++++++++++++++++++
 .../magic_prop_dec_no_undef_warn.phpt         | 28 ++++++++++++++++++
 test/repro/maintainer_gap_magic_prop_dec.php  | 10 +++++++
 .../maintainer_gap_magic_prop_postdec.php     | 10 +++++++
 6 files changed, 110 insertions(+)
 create mode 100644 test/compliance/MagicPropDecNoUndefWarnJITTest.php
 create mode 100644 test/compliance/MagicPropDecNoUndefWarnVMTest.php
 create mode 100644 test/compliance/cases/language/magic_prop_dec_no_undef_warn.phpt
 create mode 100644 test/repro/maintainer_gap_magic_prop_dec.php
 create mode 100644 test/repro/maintainer_gap_magic_prop_postdec.php

diff --git a/phpunit.xml.dist b/phpunit.xml.dist
index 6154947a69b..fd3ff804565 100644
--- a/phpunit.xml.dist
+++ b/phpunit.xml.dist
@@ -533,6 +533,10 @@
             <file>./test/compliance/UnserializeEmptySilentJITTest.php</file>
             <file>./test/compliance/DynPropIncUndefinedWarnVMTest.php</file>
             <file>./test/compliance/DynPropIncUndefinedWarnJITTest.php</file>
+            <file>./test/compliance/MagicPropIncNoUndefWarnVMTest.php</file>
+            <file>./test/compliance/MagicPropIncNoUndefWarnJITTest.php</file>
+            <file>./test/compliance/MagicPropDecNoUndefWarnVMTest.php</file>
+            <file>./test/compliance/MagicPropDecNoUndefWarnJITTest.php</file>
             <file>./test/compliance/XmlGetCurrentReflectionVMTest.php</file>
             <file>./test/compliance/XmlParserGetOptionReflectionVMTest.php</file>
             <file>./test/compliance/XmlParserFreeReflectionVMTest.php</file>
diff --git a/test/compliance/MagicPropDecNoUndefWarnJITTest.php b/test/compliance/MagicPropDecNoUndefWarnJITTest.php
new file mode 100644
index 00000000000..1b29cfaea82
--- /dev/null
+++ b/test/compliance/MagicPropDecNoUndefWarnJITTest.php
@@ -0,0 +1,29 @@
+<?php
+
+declare(strict_types=1);
+
+namespace PHPCompiler;
+
+require_once __DIR__.'/../BaseTest.php';
+
+/**
+ * JIT: --$obj->n / $obj->n-- with __get/__set emits no Undefined property (#32014).
+ */
+final class MagicPropDecNoUndefWarnJITTest extends BaseTest
+{
+    protected static string $DIR = __DIR__;
+
+    public static function providePHPTests(): \Generator
+    {
+        $file = 'magic_prop_dec_no_undef_warn.phpt';
+        yield $file => self::parsePHPT(
+            __DIR__.'/cases/language/'.$file,
+            $file
+        );
+    }
+
+    public function setUp(): void
+    {
+        $this->BIN = realpath(__DIR__.'/../../bin/jit.php');
+    }
+}
diff --git a/test/compliance/MagicPropDecNoUndefWarnVMTest.php b/test/compliance/MagicPropDecNoUndefWarnVMTest.php
new file mode 100644
index 00000000000..451f13b0e06
--- /dev/null
+++ b/test/compliance/MagicPropDecNoUndefWarnVMTest.php
@@ -0,0 +1,29 @@
+<?php
+
+declare(strict_types=1);
+
+namespace PHPCompiler;
+
+require_once __DIR__.'/../BaseTest.php';
+
+/**
+ * VM: --$obj->n / $obj->n-- with __get/__set emits no Undefined property (#32014).
+ */
+final class MagicPropDecNoUndefWarnVMTest extends BaseTest
+{
+    protected static string $DIR = __DIR__;
+
+    public static function providePHPTests(): \Generator
+    {
+        $file = 'magic_prop_dec_no_undef_warn.phpt';
+        yield $file => self::parsePHPT(
+            __DIR__.'/cases/language/'.$file,
+            $file
+        );
+    }
+
+    public function setUp(): void
+    {
+        $this->BIN = realpath(__DIR__.'/../../bin/vm.php');
+    }
+}
diff --git a/test/compliance/cases/language/magic_prop_dec_no_undef_warn.phpt b/test/compliance/cases/language/magic_prop_dec_no_undef_warn.phpt
new file mode 100644
index 00000000000..2568678f09a
--- /dev/null
+++ b/test/compliance/cases/language/magic_prop_dec_no_undef_warn.phpt
@@ -0,0 +1,28 @@
+--TEST--
+Language: --$obj->n / $obj->n-- with __get/__set emits no Undefined property (#32014, zend_object_handlers.c)
+--FILE--
+<?php
+error_reporting(E_ALL);
+class M {
+    private $d = ['n' => 1];
+    public function __get($k) { return $this->d[$k]; }
+    public function __set($k, $v) { $this->d[$k] = $v; }
+}
+$errs = [];
+set_error_handler(static function (int $errno, string $errstr) use (&$errs): bool {
+    $errs[] = [$errno, $errstr];
+    return true;
+});
+$m = new M();
+--$m->n;
+restore_error_handler();
+foreach ($errs as $e) {
+    echo "err[{$e[0]}] {$e[1]}\n";
+}
+echo "dec=", $m->n, "\n";
+$m = new M();
+$m->n--;
+echo "postdec=", $m->n, "\n";
+--EXPECT--
+dec=0
+postdec=0
diff --git a/test/repro/maintainer_gap_magic_prop_dec.php b/test/repro/maintainer_gap_magic_prop_dec.php
new file mode 100644
index 00000000000..dc277dbb08c
--- /dev/null
+++ b/test/repro/maintainer_gap_magic_prop_dec.php
@@ -0,0 +1,10 @@
+<?php
+error_reporting(E_ALL);
+class M {
+    private $d = ['n' => 1];
+    public function __get($k) { return $this->d[$k]; }
+    public function __set($k, $v) { $this->d[$k] = $v; }
+}
+$m = new M();
+--$m->n;
+echo 'dec=', $m->n, "\n";
diff --git a/test/repro/maintainer_gap_magic_prop_postdec.php b/test/repro/maintainer_gap_magic_prop_postdec.php
new file mode 100644
index 00000000000..42710ead767
--- /dev/null
+++ b/test/repro/maintainer_gap_magic_prop_postdec.php
@@ -0,0 +1,10 @@
+<?php
+error_reporting(E_ALL);
+class M {
+    private $d = ['n' => 1];
+    public function __get($k) { return $this->d[$k]; }
+    public function __set($k, $v) { $this->d[$k] = $v; }
+}
+$m = new M();
+$m->n--;
+echo 'postdec=', $m->n, "\n";