From 59d909230bedeb85c877ee540f475ade2d9da9df Mon Sep 17 00:00:00 2001
From: sergioperezcheco <checo520@outlook.com>
Date: Mon, 19 Oct 2026 19:21:50 +0800
Subject: [PATCH] Clear stale node connections before reconnecting an AST

Preserve non-connection attributes and the inactive reference namespace while rebuilding links after AST edits.

Assisted-by: Hermes Agent (Nous Research)
Signed-off-by: sergioperezcheco <checo520@outlook.com>
---
 .../NodeVisitor/NodeConnectingVisitor.php     |  9 +++
 .../NodeVisitor/NodeConnectingVisitorTest.php | 60 +++++++++++++++++++
 2 files changed, 69 insertions(+)

diff --git a/lib/PhpParser/NodeVisitor/NodeConnectingVisitor.php b/lib/PhpParser/NodeVisitor/NodeConnectingVisitor.php
index 70e051e2d9..b6b6a962ee 100644
--- a/lib/PhpParser/NodeVisitor/NodeConnectingVisitor.php
+++ b/lib/PhpParser/NodeVisitor/NodeConnectingVisitor.php
@@ -39,6 +39,15 @@ public function beforeTraverse(array $nodes) {
     }
 
     public function enterNode(Node $node) {
+        // Reconnecting a modified tree must not retain links from its old topology.
+        $attributes = $node->getAttributes();
+        if ($this->weakReferences) {
+            unset($attributes['weak_parent'], $attributes['weak_previous'], $attributes['weak_next']);
+        } else {
+            unset($attributes['parent'], $attributes['previous'], $attributes['next']);
+        }
+        $node->setAttributes($attributes);
+
         if (!empty($this->stack)) {
             $parent = $this->stack[count($this->stack) - 1];
             if ($this->weakReferences) {
diff --git a/test/PhpParser/NodeVisitor/NodeConnectingVisitorTest.php b/test/PhpParser/NodeVisitor/NodeConnectingVisitorTest.php
index c9ac5e898a..c7c31a8377 100644
--- a/test/PhpParser/NodeVisitor/NodeConnectingVisitorTest.php
+++ b/test/PhpParser/NodeVisitor/NodeConnectingVisitorTest.php
@@ -31,6 +31,66 @@ public function testConnectsNodeToItsParentNodeAndItsSiblingNodes(): void {
         $this->assertSame(Else_::class, get_class($node->getAttribute('next')));
     }
 
+    /** @dataProvider provideReferenceModes */
+    public function testReconnectsReorderedNodes(bool $weakReferences): void {
+        $ast = (new ParserFactory())->createForNewestSupportedVersion()->parse(
+            '<?php echo 1; echo 2; echo 3;'
+        );
+        $traverser = new NodeTraverser(new NodeConnectingVisitor($weakReferences));
+        $traverser->traverse($ast);
+        $ast = [$ast[2], $ast[1], $ast[0]];
+        $traverser->traverse($ast);
+        $prefix = $weakReferences ? 'weak_' : '';
+        $this->assertNull($ast[0]->getAttribute($prefix . 'previous'));
+        $this->assertNull($ast[2]->getAttribute($prefix . 'next'));
+        $previous = $ast[1]->getAttribute($prefix . 'previous');
+        $next = $ast[1]->getAttribute($prefix . 'next');
+        $this->assertSame($ast[0], $weakReferences ? $previous->get() : $previous);
+        $this->assertSame($ast[2], $weakReferences ? $next->get() : $next);
+    }
+
+    /** @dataProvider provideReferenceModes */
+    public function testReconnectsPromotedNode(bool $weakReferences): void {
+        $ast = (new ParserFactory())->createForNewestSupportedVersion()->parse(
+            '<?php if (true) { echo 1; echo 2; }'
+        );
+        $traverser = new NodeTraverser(new NodeConnectingVisitor($weakReferences));
+        $traverser->traverse($ast);
+        $this->assertInstanceOf(If_::class, $ast[0]);
+        $node = $ast[0]->stmts[0];
+        $attributes = $node->getAttributes();
+        $traverser->traverse([$node]);
+        $prefix = $weakReferences ? 'weak_' : '';
+        $this->assertNull($node->getAttribute($prefix . 'parent'));
+        $this->assertNull($node->getAttribute($prefix . 'previous'));
+        $this->assertNull($node->getAttribute($prefix . 'next'));
+        $this->assertSame($attributes['startLine'], $node->getStartLine());
+    }
+
+    /** @dataProvider provideReferenceModes */
+    public function testReconnectsAfterRemovingSiblings(bool $weakReferences): void {
+        $ast = (new ParserFactory())->createForNewestSupportedVersion()->parse(
+            '<?php echo 1; echo 2; echo 3;'
+        );
+        $traverser = new NodeTraverser(new NodeConnectingVisitor($weakReferences));
+        $traverser->traverse($ast);
+        $node = $ast[1];
+        $node->setAttribute('custom', 'preserved');
+        $otherAttribute = $weakReferences ? 'next' : 'weak_next';
+        $node->setAttribute($otherAttribute, 'independent-mode');
+        $traverser->traverse([$node]);
+        $prefix = $weakReferences ? 'weak_' : '';
+        $this->assertFalse($node->hasAttribute($prefix . 'previous'));
+        $this->assertFalse($node->hasAttribute($prefix . 'next'));
+        $this->assertSame('preserved', $node->getAttribute('custom'));
+        $this->assertSame('independent-mode', $node->getAttribute($otherAttribute));
+    }
+
+    /** @return array<array{bool}> */
+    public function provideReferenceModes(): array {
+        return [[false], [true]];
+    }
+
     public function testWeakReferences(): void {
         $ast = (new ParserFactory())->createForNewestSupportedVersion()->parse(
             '<?php if (true) {} else {}'