From 9c6bdae556fea842432ed46c17985f083d7186fb Mon Sep 17 00:00:00 2001
From: Mihai Parparita <mihai@tailscale.com>
Date: Mon, 12 Sep 2022 17:44:35 -0700
Subject: [PATCH] cmd/tsconnect: use the parent window for `beforeunload` event
 listener

The SSH session may be rendered in a different window that the one that
is executing the script.

Signed-off-by: Mihai Parparita <mihai@tailscale.com>
---
 cmd/tsconnect/src/lib/ssh.ts | 10 ++++------
 1 file changed, 4 insertions(+), 6 deletions(-)

diff --git a/cmd/tsconnect/src/lib/ssh.ts b/cmd/tsconnect/src/lib/ssh.ts
index f6dc62aac..defd9b739 100644
--- a/cmd/tsconnect/src/lib/ssh.ts
+++ b/cmd/tsconnect/src/lib/ssh.ts
@@ -14,6 +14,7 @@ export function runSSHSession(
   onDone: () => void,
   terminalOptions?: ITerminalOptions
 ) {
+  const parentWindow = termContainerNode.ownerDocument.defaultView ?? window
   const term = new Terminal({
     cursorBlink: true,
     allowProposedApi: true,
@@ -57,22 +58,19 @@ export function runSSHSession(
       resizeObserver?.disconnect()
       term.dispose()
       if (handleBeforeUnload) {
-        window.removeEventListener("beforeunload", handleBeforeUnload)
+        parentWindow.removeEventListener("beforeunload", handleBeforeUnload)
       }
       onDone()
     },
   })
 
   // Make terminal and SSH session track the size of the containing DOM node.
-  resizeObserver =
-    new termContainerNode.ownerDocument.defaultView!.ResizeObserver(() =>
-      fitAddon.fit()
-    )
+  resizeObserver = new parentWindow.ResizeObserver(() => fitAddon.fit())
   resizeObserver.observe(termContainerNode)
   term.onResize(({ rows, cols }) => sshSession.resize(rows, cols))
 
   // Close the session if the user closes the window without an explicit
   // exit.
   handleBeforeUnload = () => sshSession.close()
-  window.addEventListener("beforeunload", handleBeforeUnload)
+  parentWindow.addEventListener("beforeunload", handleBeforeUnload)
 }