extensionUtils: Allow getCurrentExtension() to be called from anyone

Currently it's assumed only an extension can call this method. However
it can be useful if any part of the shell want to know if it was invoked
by an extension.

https://bugzilla.gnome.org/show_bug.cgi?id=770717

diff --git a/js/misc/extensionUtils.js b/js/misc/extensionUtils.js
index 1d1221c35cb50c2d6cb11f75c9cdf694b3aa4d97..aff91acc719a64e76de2102012f1b6aaa600ae26 100644 (file)
--- a/js/misc/extensionUtils.js
+++ b/js/misc/extensionUtils.js
@@ -21,14 +21,25 @@ const ExtensionType = {
 // Maps uuid -> metadata object
 const extensions = {};
 
+/**
+ * getCurrentExtension:
+ *
+ * Returns the current extension, or null if not called from an extension.
+ */
 function getCurrentExtension() {
-    let stack = (new Error()).stack;
-
-    // Assuming we're importing this directly from an extension (and we shouldn't
-    // ever not be), its UUID should be directly in the path here.
-    let extensionStackLine = stack.split('\n')[1];
+    let stack = (new Error()).stack.split('\n');
+    let extensionStackLine;
+
+    // Search for an occurrence of an extension stack frame
+    // Start at 1 because 0 is the stack frame of this function
+    for (let i = 1; i < stack.length; i++) {
+        if (stack[i].indexOf('/gnome-shell/extensions/') > -1) {
+            extensionStackLine = stack[i];
+            break;
+        }
+    }
     if (!extensionStackLine)
-        throw new Error('Could not find current extension');
+        return null;
 
     // The stack line is like:
     //   init([object Object])@/home/user/data/gnome-shell/extensions/u@u.id/prefs.js:8
@@ -38,7 +49,7 @@ function getCurrentExtension() {
     //   @/home/user/data/gnome-shell/extensions/u@u.id/prefs.js:8
     let match = new RegExp('@(.+):\\d+').exec(extensionStackLine);
     if (!match)
-        throw new Error('Could not find current extension');
+        return null;
 
     let path = match[1];
     let file = Gio.File.new_for_path(path);
@@ -52,7 +63,7 @@ function getCurrentExtension() {
         file = file.get_parent();
     }
 
-    throw new Error('Could not find current extension');
+    return null;
 }
 
 /**