From 9b067a2791ae40f1cf3ef1cd1e23795fa0e9e5e6 Mon Sep 17 00:00:00 2001
From: Liang Gong <lgong@meta.com>
Date: Sun, 24 Sep 2023 20:47:20 -0700
Subject: [PATCH] fix(core): do not mark FiberNode dominated by attached HTML
 element as unmounted

Summary: This diff filters out a memory leak trace pattern: if a React FiberNode is dominated by an attached HTML DOM element. It is not considered as unmounted Fiber Node.

Reviewed By: tulga1970

Differential Revision: D49250856

fbshipit-source-id: 46bdaf7d4cfb12e1d0b26e277483dccc2ba67fba
---
 packages/core/src/lib/Utils.ts | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/packages/core/src/lib/Utils.ts b/packages/core/src/lib/Utils.ts
index 4ea655716..ad68b5334 100644
--- a/packages/core/src/lib/Utils.ts
+++ b/packages/core/src/lib/Utils.ts
@@ -586,7 +586,13 @@ function markDetachedFiberNode(node: IHeapNode): boolean {
     // if a Fiber node whose dominator is neither root nor
     // another Fiber node, then consider it as detached Fiber node
     if (cur.dominatorNode && cur.dominatorNode.id !== 1) {
-      if (!isFiberNode(cur.dominatorNode)) {
+      if (
+        isDOMNodeIncomplete(cur.dominatorNode) &&
+        !isDetachedDOMNode(cur.dominatorNode)
+      ) {
+        // skip the direct marking of detached DOM nodes here
+        // if the Fiber Node is dominated by an attached DOM element
+      } else if (!isFiberNode(cur.dominatorNode)) {
         cur.markAsDetached();
       }
     }