[gnome-shell] screencast: Validate parameters of ScreencastArea

[Florian Müllner <fmuellner src gnome org>]

commit e8d9a4bd49e99a80797d0473b8b73f4aea1bbf29
Author: Florian Müllner <fmuellner gnome org>
Date:   Mon Nov 4 14:09:19 2013 +0100

    screencast: Validate parameters of ScreencastArea
    
    ... just as we do for screenshots.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=699752

 js/ui/screencast.js |   10 ++++++++++
 1 files changed, 10 insertions(+), 0 deletions(-)
---
diff --git a/js/ui/screencast.js b/js/ui/screencast.js
index 23d6a42..7908ff1 100644
--- a/js/ui/screencast.js
+++ b/js/ui/screencast.js
@@ -137,6 +137,16 @@ const ScreencastService = new Lang.Class({
         if (!recorder.is_recording()) {
             let [x, y, width, height, fileTemplate, options] = params;
 
+            if (x < 0 || y < 0 ||
+                width <= 0 || height <= 0 ||
+                x + width > global.screen_width ||
+                y + height > global.screen_height) {
+                invocation.return_error_literal(Gio.IOErrorEnum,
+                                                Gio.IOErrorEnum.CANCELLED,
+                                                "Invalid params");
+                return;
+            }
+
             recorder.set_file_template(fileTemplate);
             recorder.set_area(x, y, width, height);
             this._applyOptionalParameters(recorder, options);