[DeadCode] Fix infinite loop on RemoveDeadStmtRector + RemoveUnusedVa…

…riableAssignRector (#5666)

rules/DeadCode/Rector/Expression/RemoveDeadStmtRector.php

@@ -76,14 +76,15 @@ public function refactor(Node $node): array|Node|null|int
             return null;
         }
 
-        $node->expr = array_shift($livingCode);
+        $newNode = clone $node;
+        $newNode->expr = array_shift($livingCode);
 
         $newNodes = [];
         foreach ($livingCode as $singleLivingCode) {
             $newNodes[] = new Expression($singleLivingCode);
         }
 
-        $newNodes[] = $node;
+        $newNodes[] = $newNode;
 
         return $newNodes;
     }

tests/Issues/InfiniteLoop/DeadStmtUnusedVariableTest.php

@@ -0,0 +1,28 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Rector\Tests\Issues\InfiniteLoop;
+
+use Iterator;
+use PHPUnit\Framework\Attributes\DataProvider;
+use Rector\Testing\PHPUnit\AbstractRectorTestCase;
+
+final class DeadStmtUnusedVariableTest extends AbstractRectorTestCase
+{
+    #[DataProvider('provideData')]
+    public function test(string $filePath): void
+    {
+        $this->doTestFile($filePath);
+    }
+
+    public static function provideData(): Iterator
+    {
+        return self::yieldFilesFromDirectory(__DIR__ . '/FixtureDeadStmtUnusedVariable');
+    }
+
+    public function provideConfigFilePath(): string
+    {
+        return __DIR__ . '/config/dead_stmt_unused_variable.php';
+    }
+}

tests/Issues/InfiniteLoop/FixtureDeadStmtUnusedVariable/fixture.php.inc

@@ -0,0 +1,28 @@
+<?php
+
+namespace Rector\Tests\CodeQuality\Rector\BooleanNot\SimplifyDeMorganBinaryRector\FixtureDeadStmtUnusedVariable;
+
+class X
+{
+    public function f()
+    {
+        $var = $object->a() . $object->b();
+    }
+}
+
+?>
+-----
+<?php
+
+namespace Rector\Tests\CodeQuality\Rector\BooleanNot\SimplifyDeMorganBinaryRector\FixtureDeadStmtUnusedVariable;
+
+class X
+{
+    public function f()
+    {
+        $object->b();
+        $object->a();
+    }
+}
+
+?>

tests/Issues/InfiniteLoop/config/dead_stmt_unused_variable.php

@@ -0,0 +1,13 @@
+<?php
+
+declare(strict_types=1);
+
+use Rector\Config\RectorConfig;
+use Rector\DeadCode\Rector\Assign\RemoveUnusedVariableAssignRector;
+use Rector\DeadCode\Rector\Expression\RemoveDeadStmtRector;
+
+return RectorConfig::configure()
+    ->withRules([
+        RemoveDeadStmtRector::class,
+        RemoveUnusedVariableAssignRector::class
+    ]);