Issue 3697 - Fall back to i18n.getUILanguage if @ui_locale isn't supported

lib/utils.js

Index: lib/utils.js
diff --git a/lib/utils.js b/lib/utils.js
index 33e2fca6de0e6311cdff38eb84e402679c97db34..5b8746aa389d014cf3028ef7696e64087e39f72d 100644
--- a/lib/utils.js
+++ b/lib/utils.js
@@ -44,10 +44,37 @@ var Utils = exports.Utils = {
   },
   get appLocale()
   {
-    var locale = ext.i18n.getMessage("@@ui_locale").replace(/_/g, "-");
+    var locale;
+    try
+    {
+      locale = ext.i18n.getMessage("@@ui_locale");
+    }
+    catch (exception)
+    {
+      // Edge does not yet (?) support @@ui_locale, throwing an exception here.
+    }
+    if (!locale)
+      locale = ext.i18n.getUILanguage();

[Sebastian Noack, 2017/08/23 12:26:44]

It seems we can use chrome.i18n.getUILanguage() regardless, without checking for
getMessage("@@ui_locale") first, since all supported browsers and browser
versions seem to support it.

+    locale = locale.replace(/_/g, "-");
     Object.defineProperty(this, "appLocale", {value: locale, enumerable: true});
     return this.appLocale;
   },
+  get readingDirection()
+  {
+    var direction;
+    try
+    {
+      direction = ext.i18n.getMessage("@@bidi_dir");
+    }
+    catch (exception)
+    {
+      // Edge does not yet (?) support @@bidi_dir, throwing an exception here.
+    }
+    if (!direction)
+      direction = /^(ar|fa|he|ug|ur)(_|$)/.test(this.appLocale) ? "rtl" : "ltr";
+    Object.defineProperty(this, "readingDirection", {value: direction, enumerable: true});
+    return this.readingDirection;
+  },
   generateChecksum: function(lines)
   {
     // We cannot calculate MD5 checksums yet :-(