From e51d1740797df636a2b617b57dc7101cff37e402 Mon Sep 17 00:00:00 2001
From: Ray Lothian <ray.lothian@yahoo.com>
Date: Sun, 4 Nov 2018 10:18:40 +0100
Subject: [PATCH] allow setting blank UA using 'empty' keyword

---
 common.js             | 14 +++++++++-----
 data/popup/index.html |  2 +-
 2 files changed, 10 insertions(+), 6 deletions(-)

diff --git a/common.js b/common.js
index cc0da00..fe0b4a0 100644
--- a/common.js
+++ b/common.js
@@ -199,7 +199,7 @@ var onBeforeSendHeaders = ({tabId, url, requestHeaders, type}) => {
   if (str) {
     for (let i = 0, name = requestHeaders[0].name; i < requestHeaders.length; i += 1, name = requestHeaders[i].name) {
       if (name === 'User-Agent' || name === 'user-agent') {
-        requestHeaders[i].value = str;
+        requestHeaders[i].value = str === 'empty' ? '' : str;
         return {
           requestHeaders
         };
@@ -215,16 +215,20 @@ var onCommitted = ({frameId, url, tabId}) => {
     }
     const o = cache[tabId] || ua.object(tabId);
     if (o.userAgent) {
+      let {userAgent, appVersion, platform, vendor} = o;
+      if (o.userAgent === 'empty') {
+        userAgent = appVersion = platform = vendor = '';
+      }
       chrome.tabs.executeScript(tabId, {
         runAt: 'document_start',
         frameId,
         code: `{
           const script = document.createElement('script');
           script.textContent = \`{
-            navigator.__defineGetter__('userAgent', () => '${o.userAgent}');
-            navigator.__defineGetter__('appVersion', () => '${o.appVersion}');
-            navigator.__defineGetter__('platform', () => '${o.platform}');
-            navigator.__defineGetter__('vendor', () => '${o.vendor}');
+            navigator.__defineGetter__('userAgent', () => '${userAgent}');
+            navigator.__defineGetter__('appVersion', () => '${appVersion}');
+            navigator.__defineGetter__('platform', () => '${platform}');
+            navigator.__defineGetter__('vendor', () => '${vendor}');
           }\`;
           document.documentElement.appendChild(script);
           script.remove();
diff --git a/data/popup/index.html b/data/popup/index.html
index b7d40ab..6c82740 100644
--- a/data/popup/index.html
+++ b/data/popup/index.html
@@ -158,7 +158,7 @@
       <input type="button" value="Window" title="Set this string as this window's User-Agent string" data-cmd="window">
       <input type="button" value="Reset" title="Reset User-Agent string to the default one. This will not reset window-based UA strings. To reset them, use the 'Restart' button" style="margin-left: 2px;" data-cmd="reset">
     </div>
-    <input id="ua" type="text" placeholder="Your preferred user-agent string">
+    <input id="ua" type="text" placeholder="Your preferred user-agent string" title="To set blank user-agent string, use 'empty' keyword">
     <div id="explore"></div>
     <script src="ua-parser.min.js"></script>
     <script src="index.js"></script>