From d34baca7dcd92df530457e49e07ebaf0ad5f0456 Mon Sep 17 00:00:00 2001
From: tianfenghan <rango@swoole.com>
Date: Fri, 31 Jul 2026 18:26:01 +0800
Subject: [PATCH] fix(optimizer): parenthesize null-check expressions

---
 phpunit/code/assign-not-identical-null.php | 17 +++++++++++++++++
 phpunit/src/OperatorTest.php               | 17 +++++++++++++++++
 src/Optimizer/FuncCallOptimizer.php        |  2 +-
 src/Parser/BinaryOpTrait.php               |  5 ++++-
 4 files changed, 39 insertions(+), 2 deletions(-)
 create mode 100644 phpunit/code/assign-not-identical-null.php

diff --git a/phpunit/code/assign-not-identical-null.php b/phpunit/code/assign-not-identical-null.php
new file mode 100644
index 00000000..67d377fb
--- /dev/null
+++ b/phpunit/code/assign-not-identical-null.php
@@ -0,0 +1,17 @@
+<?php
+
+class AssignedValueNullCheck
+{
+    public function check(): bool
+    {
+        if (!is_null($error = error_get_last()) && $this->isFatal($error['type'])) {
+            return true;
+        }
+        return false;
+    }
+
+    private function isFatal(int $type): bool
+    {
+        return $type > 0;
+    }
+}
diff --git a/phpunit/src/OperatorTest.php b/phpunit/src/OperatorTest.php
index 04f2c2bf..468f7d29 100644
--- a/phpunit/src/OperatorTest.php
+++ b/phpunit/src/OperatorTest.php
@@ -22,6 +22,23 @@ class OperatorTest extends \BaseTest
         $this->assertStringContainsString('php::same(php::true_, value)', $cpp);
     }
 
+    public function testAssignedValueNotIdenticalToNullIsParenthesized(): void
+    {
+        global $translator;
+        $compiler = \TypePhp\CompilerTest::create(ROOT_PATH);
+        $translator = $compiler;
+        $testFile = __DIR__ . '/../code/assign-not-identical-null.php';
+        $compiler->addFiles([$testFile]);
+        $compiler->prepareFile($testFile);
+        $cppFile = $compiler->convertFile($testFile);
+        $cpp = file_get_contents($cppFile);
+
+        $this->assertMatchesRegularExpression(
+            '/!\(\(error = php::call\([^\n]+\)\)\.isNull\(\)\)/',
+            $cpp,
+        );
+    }
+
     public function testLiteralIntDivideByZeroDoesNotCompile(): void
     {
         $this->exec('Cannot divide or modulo by zero', 'divide-by-zero-int.php');
diff --git a/src/Optimizer/FuncCallOptimizer.php b/src/Optimizer/FuncCallOptimizer.php
index 5e3e4d46..2c1c865d 100644
--- a/src/Optimizer/FuncCallOptimizer.php
+++ b/src/Optimizer/FuncCallOptimizer.php
@@ -612,7 +612,7 @@ trait FuncCallOptimizer
 
     protected function genIsNull(string $n, Node\Expr\FuncCall $e, array $c): string
     {
-        return $this->parseIdentifier($e->args[0]->value) . '.isNull()';
+        return '(' . $this->parseExprAsValue($e->args[0]->value) . ').isNull()';
     }
 
     protected function genIsCallable(string $n, Node\Expr\FuncCall $e, array $c): string|false
diff --git a/src/Parser/BinaryOpTrait.php b/src/Parser/BinaryOpTrait.php
index feae8dcb..b17f1eee 100644
--- a/src/Parser/BinaryOpTrait.php
+++ b/src/Parser/BinaryOpTrait.php
@@ -388,7 +388,10 @@ trait BinaryOpTrait
         $left  = $this->parseCompareExpr($expr->left);
         $right = $this->parseCompareExpr($expr->right);
         if ($right === 'nullptr') {
-            return $left . '.isNull()';
+            // The left operand may itself be an assignment or another compound
+            // expression. Parenthesize it before invoking Variant::isNull(), or
+            // C++ binds the member access to the assignment's RHS instead.
+            return '(' . $left . ').isNull()';
         }
         if ($optimized = $this->optimizeIdenticalOp($expr->left, $expr->right, $left, $right)) {
             return $optimized;