From c639467022d48ec6e915d03f3eb848b7e205beab Mon Sep 17 00:00:00 2001
From: Mehmet Bektas <mbektasgh@outlook.com>
Date: Sun, 20 Feb 2022 20:02:45 -0800
Subject: [PATCH] fix for PDF rendering

---
 src/main/preload.ts  | 45 ++++++++++++++++++++++++++++++++++++++++++++
 src/main/sessions.ts |  3 +--
 2 files changed, 46 insertions(+), 2 deletions(-)
 create mode 100644 src/main/preload.ts

diff --git a/src/main/preload.ts b/src/main/preload.ts
new file mode 100644
index 00000000..a1c498a2
--- /dev/null
+++ b/src/main/preload.ts
@@ -0,0 +1,45 @@
+// atob implementation below is modified from node.js source 
+// (https://github.com/nodejs/node/blob/master/lib/buffer.js)
+// and copyright below is for it
+
+// Copyright Joyent, Inc. and other Node contributors.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a
+// copy of this software and associated documentation files (the
+// "Software"), to deal in the Software without restriction, including
+// without limitation the rights to use, copy, modify, merge, publish,
+// distribute, sublicense, and/or sell copies of the Software, and to permit
+// persons to whom the Software is furnished to do so, subject to the
+// following conditions:
+//
+// The above copyright notice and this permission notice shall be included
+// in all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
+// NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
+// DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
+// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
+// USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+/*
+  Override atob implementation with a modified version that allows whitespaces.
+  When contextIsolation is off, electron uses atob implementation from node.js
+  which does not allow whitespaces. this override won't be needed once
+  contextIsolation is turned on.
+*/
+window.atob = (input): string => {
+    const kBase64Digits =
+        'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=';
+
+    // remove whitespace
+    input = `${input}`.replace(/\s/g, "");
+    for (let n = 0; n < input.length; n++) {
+        if (!kBase64Digits.includes(input[n])) {
+            throw new DOMException('Invalid character', 'InvalidCharacterError');
+        }
+    }
+
+    return Buffer.from(input, 'base64').toString('latin1');
+}
diff --git a/src/main/sessions.ts b/src/main/sessions.ts
index 506e01d3..34dda6ab 100644
--- a/src/main/sessions.ts
+++ b/src/main/sessions.ts
@@ -404,8 +404,7 @@ class JupyterLabSession {
             webPreferences: {
                 nodeIntegration: true,
                 contextIsolation: false,
-                // disable native window open to prevent exposing node.js scripts in popups
-                nativeWindowOpen: false
+                preload: path.join(__dirname, './preload.js'),
             }
         });