[gnome-shell] screenshot: don't fire flash if we failed to take picture

[Cosimo Cecchi <cosimoc src gnome org>]

commit 123fb350ce72e89b7dc72adfa202aad44a9070a0
Author: Cosimo Cecchi <cosimoc gnome org>
Date:   Fri Nov 9 13:13:22 2012 -0500

    screenshot: don't fire flash if we failed to take picture
    
    https://bugzilla.gnome.org/show_bug.cgi?id=688004

 js/ui/shellDBus.js |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/js/ui/shellDBus.js b/js/ui/shellDBus.js
index 7a625af..b4d8966 100644
--- a/js/ui/shellDBus.js
+++ b/js/ui/shellDBus.js
@@ -111,7 +111,7 @@ const GnomeShell = new Lang.Class({
     },
 
     _onScreenshotComplete: function(obj, result, area, flash, invocation) {
-        if (flash) {
+        if (flash && result) {
             let flashspot = new Flashspot.Flashspot(area);
             flashspot.fire();
         }