From 664b13da3289597966bfb5b7dd5e347233d48524 Mon Sep 17 00:00:00 2001
From: Evan Wiederspan <evan.wiederspan@gmail.com>
Date: Tue, 13 Dec 2022 11:20:16 -0800
Subject: [PATCH] Don't recreate a model on channel open if the model already
 exists (#31)

We believe this to be the root cause of
https://github.com/googlecolab/colabtools/issues/3270.
---
 src/manager.ts | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/manager.ts b/src/manager.ts
index 0120db4..b6d5ddd 100644
--- a/src/manager.ts
+++ b/src/manager.ts
@@ -229,6 +229,11 @@ export class Manager extends ManagerBase implements IWidgetManager {
       return;
     }
     const classicComm = new ClassicComm(id, comm);
+    if (this.models.has(id)) {
+      // This model has already been created, skip calling handle_com_open which
+      // would re-create it.
+      return;
+    }
     await this.handle_comm_open(classicComm, {
       header: {} as services.KernelMessage.IHeader<'comm_open'>,
       metadata: {version: base.PROTOCOL_VERSION},