From 14dadb48ffece6bc2977e260bef77d87b1436966 Mon Sep 17 00:00:00 2001
From: Eoghan Murray <eoghan@getthere.ie>
Date: Mon, 9 Oct 2023 14:14:19 +0100
Subject: [PATCH] Fix a replay issue where the 500ms timeout was being hit

 - 3.7K nodes being inserted, with ~200 <tr>s as the root nodes making up the `resolveTrees`
 - each table row was dependent on the next, resulting in cascading failures; 19K repopulation of queue due to `nextNotInDOM`, and an additional cascading 350K repopulation of queue due to missing parent nodes
---
 packages/rrweb/src/utils.ts | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/packages/rrweb/src/utils.ts b/packages/rrweb/src/utils.ts
index 604c8810e2..aee2e8757c 100644
--- a/packages/rrweb/src/utils.ts
+++ b/packages/rrweb/src/utils.ts
@@ -344,6 +344,7 @@ export function queueToResolveTrees(queue: addedNodeMutation[]): ResolveTree[] {
     queueNodeMap[m.node.id] = nodeInTree;
     return nodeInTree;
   };
+  const rootNexts = new Set<number>();
 
   const queueNodeTrees: ResolveTree[] = [];
   for (const mutation of queue) {
@@ -368,7 +369,16 @@ export function queueToResolveTrees(queue: addedNodeMutation[]): ResolveTree[] {
       parentInTree.children.push(putIntoMap(mutation, parentInTree));
       continue;
     }
-    queueNodeTrees.push(putIntoMap(mutation, null));
+    if (nextId) {
+      rootNexts.add(nextId);
+    }
+    const rootTree = putIntoMap(mutation, null);
+    if (rootNexts.has(mutation.node.id)) {
+      // some existing tree can't be inserted until this one is (nextNotInDOM check)
+      queueNodeTrees.unshift(rootTree);
+    } else {
+      queueNodeTrees.push(rootTree);
+    }
   }
 
   return queueNodeTrees;