From eb69f55f29da40f21058f24918a0c53fb2a140f9 Mon Sep 17 00:00:00 2001
From: Alexander Zinchuk <alx.zinchuk@gmail.com>
Date: Sat, 29 Oct 2022 15:18:29 +0200
Subject: [PATCH] Teact: Fix memory leak if head is removed (#2083)

---
 src/lib/teact/teact-dom.ts | 12 ++++--------
 1 file changed, 4 insertions(+), 8 deletions(-)

diff --git a/src/lib/teact/teact-dom.ts b/src/lib/teact/teact-dom.ts
index 8d287191d..2c34a765b 100644
--- a/src/lib/teact/teact-dom.ts
+++ b/src/lib/teact/teact-dom.ts
@@ -19,7 +19,6 @@ import {
   unmountComponent,
   isFragmentElement,
 } from './teact';
-import generateIdFor from '../../util/generateIdFor';
 import { DEBUG } from '../../config';
 import { addEventListener, removeAllDelegatedListeners, removeEventListener } from './dom-events';
 import { unique } from '../../util/iteratees';
@@ -37,19 +36,16 @@ const MAPPED_ATTRIBUTES: { [k: string]: string } = {
 };
 const INDEX_KEY_PREFIX = '__indexKey#';
 
-const headsByElement: Record<string, VirtualDomHead> = {};
+const headsByElement = new WeakMap<HTMLElement, VirtualDomHead>();
 // eslint-disable-next-line @typescript-eslint/naming-convention
 let DEBUG_virtualTreeSize = 1;
 
 function render($element: VirtualElement | undefined, parentEl: HTMLElement) {
-  let headId = parentEl.getAttribute('data-teact-head-id');
-  if (!headId) {
-    headId = generateIdFor(headsByElement);
-    headsByElement[headId] = { children: [] };
-    parentEl.setAttribute('data-teact-head-id', headId);
+  if (!headsByElement.has(parentEl)) {
+    headsByElement.set(parentEl, { children: [] });
   }
 
-  const $head = headsByElement[headId];
+  const $head = headsByElement.get(parentEl)!;
   const $newElement = renderWithVirtual(parentEl, $head.children[0], $element, $head, 0);
   $head.children = $newElement ? [$newElement] : [];