apps-menu: Mark copied .desktop files as trusted

The application can already be launched from the menu without further
confirmation from the user, so there is no security gain in asking the
user to trust it when launched from the desktop - just set the appropriate
attributes of the newly copied file to mark it as trusted to nautilus.

https://bugzilla.gnome.org/show_bug.cgi?id=781596

extensions/apps-menu/extension.js

@@ -331,6 +331,30 @@ const DesktopTarget = new Lang.Class({
         return source._app.app_info;
     },
 
+    _markTrusted: function(file) {
+        let modeAttr = Gio.FILE_ATTRIBUTE_UNIX_MODE;
+        let trustedAttr = 'metadata::trusted';
+        let queryFlags = Gio.FileQueryInfoFlags.NONE;
+        let ioPriority = GLib.PRIORITY_DEFAULT;
+
+        file.query_info_async(modeAttr, queryFlags, ioPriority, null,
+            (o, res) => {
+                try {
+                    let info = o.query_info_finish(res);
+                    let mode = info.get_attribute_uint32(modeAttr) | 0100;
+
+                    info.set_attribute_uint32(modeAttr, mode);
+                    info.set_attribute_string(trustedAttr, 'yes');
+                    file.set_attributes_async (info, queryFlags, ioPriority, null,
+                        (o, res) => {
+                            o.set_attributes_finish(res);
+                        });
+                } catch(e) {
+                    log('Failed to mark file as trusted: ' + e.message);
+                }
+            });
+    },
+
     destroy: function() {
         if (this._windowAddedId)
             global.window_group.disconnect(this._windowAddedId);
@@ -362,6 +386,7 @@ const DesktopTarget = new Lang.Class({
         try {
             // copy_async() isn't introspectable :-(
             src.copy(dst, Gio.FileCopyFlags.OVERWRITE, null, null);
+            this._markTrusted(dst);
         } catch(e) {
             log('Failed to copy to desktop: ' + e.message);
         }