From fb7ac44a2fd82eb54bf1425e3e0db3391f3e7b89 Mon Sep 17 00:00:00 2001
From: Ranjan Shrestha <ranjan@sharingapples.com>
Date: Thu, 8 Feb 2024 18:01:42 +0545
Subject: [PATCH] Cleanup the existing child node before repositioning to avoid
 memory leak (#2206)

Fixes #2183, During re-renders when the child nodes where being rearranged, the new nodes were inserted without removing the existing ones.

---------

Co-authored-by: William Candillon <wcandillon@gmail.com>
---
 package/cpp/rnskia/dom/base/JsiDomNode.h | 16 ++++++++++++++++
 package/src/dom/nodes/Node.ts            |  1 +
 2 files changed, 17 insertions(+)

diff --git a/package/cpp/rnskia/dom/base/JsiDomNode.h b/package/cpp/rnskia/dom/base/JsiDomNode.h
index 3d47ec57cf..50b1cab644 100644
--- a/package/cpp/rnskia/dom/base/JsiDomNode.h
+++ b/package/cpp/rnskia/dom/base/JsiDomNode.h
@@ -370,6 +370,14 @@ class JsiDomNode : public JsiHostObject,
     enqueAsynOperation([child, weakSelf = weak_from_this()]() {
       auto self = weakSelf.lock();
       if (self) {
+        // Remove the existing instance of the child, before adding it to the
+        // end of the list
+        auto existingPosition =
+            std::find(self->_children.begin(), self->_children.end(), child);
+        if (existingPosition != self->_children.end()) {
+          self->_children.erase(existingPosition);
+        }
+
         self->_children.push_back(child);
         child->setParent(self.get());
       }
@@ -390,6 +398,14 @@ class JsiDomNode : public JsiHostObject,
     enqueAsynOperation([child, before, weakSelf = weak_from_this()]() {
       auto self = weakSelf.lock();
       if (self) {
+        // Remove the existing instance of the child
+        // before adding it in the new position
+        auto existingPosition =
+            std::find(self->_children.begin(), self->_children.end(), child);
+        if (existingPosition != self->_children.end()) {
+          self->_children.erase(existingPosition);
+        }
+
         auto position =
             std::find(self->_children.begin(), self->_children.end(), before);
         self->_children.insert(position, child);
diff --git a/package/src/dom/nodes/Node.ts b/package/src/dom/nodes/Node.ts
index 2d60647e8e..8faff97b72 100644
--- a/package/src/dom/nodes/Node.ts
+++ b/package/src/dom/nodes/Node.ts
@@ -38,6 +38,7 @@ export abstract class JsiNode<P> implements Node<P> {
   }
 
   addChild(child: Node<unknown>) {
+    this.removeChild(child);
     this._children.push(child as JsiNode<unknown>);
   }