4 files changed, 54 insertions, 0 deletions
diff --git a/application/palemoon/base/content/browser-uacompat.js b/application/palemoon/base/content/browser-uacompat.js
new file mode 100644
index 000000000..933aa55d1
--- /dev/null
+++ b/application/palemoon/base/content/browser-uacompat.js
@@ -0,0 +1,45 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+var UserAgentCompatibility = {
+  PREF_UA_COMPAT: "general.useragent.compatMode",
+  PREF_UA_COMPAT_GECKO: "general.useragent.compatMode.gecko",
+  PREF_UA_COMPAT_FIREFOX: "general.useragent.compatMode.firefox",
+  
+  init: function() {
+    this.checkPreferences();
+    Services.prefs.addObserver(this.PREF_UA_COMPAT, this, false);
+    Services.prefs.addObserver(this.PREF_UA_COMPAT_GECKO, this, false);
+    Services.prefs.addObserver(this.PREF_UA_COMPAT_FIREFOX, this, false);
+  },
+
+  uninit: function() {
+    Services.prefs.removeObserver(this.PREF_UA_COMPAT, this, false);
+    Services.prefs.removeObserver(this.PREF_UA_COMPAT_GECKO, this, false);
+    Services.prefs.removeObserver(this.PREF_UA_COMPAT_FIREFOX, this, false);
+  },
+
+  observe: function() {
+    this.checkPreferences();
+  },
+  
+  checkPreferences: function() {
+    var compatMode = Services.prefs.getIntPref(this.PREF_UA_COMPAT);
+    
+    switch(compatMode) {
+      case 0:
+        Services.prefs.setBoolPref(this.PREF_UA_COMPAT_GECKO, false);
+        Services.prefs.setBoolPref(this.PREF_UA_COMPAT_FIREFOX, false);
+        break;
+      case 1:
+        Services.prefs.setBoolPref(this.PREF_UA_COMPAT_GECKO, true);
+        Services.prefs.setBoolPref(this.PREF_UA_COMPAT_FIREFOX, false);
+        break;
+      case 2:
+        Services.prefs.setBoolPref(this.PREF_UA_COMPAT_GECKO, true);
+        Services.prefs.setBoolPref(this.PREF_UA_COMPAT_FIREFOX, true);
+        break;
+    }
+  }
+};
diff --git a/application/palemoon/base/content/browser.js b/application/palemoon/base/content/browser.js
index fc2e63393..c9f0aa4aa 100644
--- a/application/palemoon/base/content/browser.js
+++ b/application/palemoon/base/content/browser.js
@@ -7,6 +7,7 @@ var Ci = Components.interfaces;
 var Cu = Components.utils;
 
 Cu.import("resource://gre/modules/XPCOMUtils.jsm");
+Cu.import("resource://gre/modules/Services.jsm");
 Cu.import("resource:///modules/RecentWindow.jsm");
 
 XPCOMUtils.defineLazyModuleGetter(this, "CharsetMenu",
@@ -141,6 +142,7 @@ let gInitialPages = [
 #include browser-plugins.js
 #include browser-tabPreviews.js
 #include browser-thumbnails.js
+#include browser-uacompat.js
 
 #ifdef MOZ_WEBRTC
 #include browser-webrtcUI.js
@@ -917,6 +919,7 @@ var gBrowserInit = {
     TabsInTitlebar.init();
     retrieveToolbarIconsizesFromTheme();
     ToolbarIconColor.init();
+    UserAgentCompatibility.init();
 
 #ifdef XP_WIN
     if (window.matchMedia("(-moz-os-version: windows-win8)").matches &&
@@ -1293,6 +1296,8 @@ var gBrowserInit = {
     DevToolsTheme.uninit();
 #endif
 
+    UserAgentCompatibility.uninit();
+
     var enumerator = Services.wm.getEnumerator(null);
     enumerator.getNext();
     if (!enumerator.hasMoreElements()) {
diff --git a/application/palemoon/branding/official/pref/palemoon-branding.js b/application/palemoon/branding/official/pref/palemoon-branding.js
index 4f5d196d7..8e8703fb7 100644
--- a/application/palemoon/branding/official/pref/palemoon-branding.js
+++ b/application/palemoon/branding/official/pref/palemoon-branding.js
@@ -8,6 +8,8 @@ pref("app.releaseNotesURL", "http://www.palemoon.org/releasenotes.shtml");
 
 // Enable Firefox compatmode by default.
 pref("general.useragent.compatMode", 2);
+pref("general.useragent.compatMode.gecko", true);
+pref("general.useragent.compatMode.firefox", true);
 
 // ========================= updates ========================
 #if defined(XP_WIN)
diff --git a/application/palemoon/branding/unstable/pref/palemoon-branding.js b/application/palemoon/branding/unstable/pref/palemoon-branding.js
index 4c088f76d..dda6f86a5 100644
--- a/application/palemoon/branding/unstable/pref/palemoon-branding.js
+++ b/application/palemoon/branding/unstable/pref/palemoon-branding.js
@@ -8,6 +8,8 @@ pref("app.releaseNotesURL", "http://www.palemoon.org/unstable/releasenotes.shtml
 
 // Enable Firefox compatmode by default.
 pref("general.useragent.compatMode", 2);
+pref("general.useragent.compatMode.gecko", true);
+pref("general.useragent.compatMode.firefox", true);
 
 // ========================= updates ========================
 #if defined(XP_WIN)