From b28be877bdc3e4db1474a0f7d8fa4e7a64c27b1c Mon Sep 17 00:00:00 2001
From: Daniel Imms <daimms@microsoft.com>
Date: Mon, 23 Sep 2019 07:47:02 -0700
Subject: [PATCH] Fix NPE when open called twice

Fixes #2433
---
 src/Terminal.ts | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/Terminal.ts b/src/Terminal.ts
index d793abfc86..098c383b58 100644
--- a/src/Terminal.ts
+++ b/src/Terminal.ts
@@ -604,8 +604,8 @@ export class Terminal extends Disposable implements ITerminal, IDisposable, IInp
     // Performance: Add viewport and helper elements from the fragment
     this.element.appendChild(fragment);
 
-    this._theme = this.options.theme;
-    this.options.theme = null;
+    this._theme = this.options.theme || this._theme;
+    this.options.theme = undefined;
     this._colorManager = new ColorManager(document, this.options.allowTransparency);
     this._colorManager.setTheme(this._theme);