From 4ee214295b6a11c9d8a55fe66f6d896ab7774478 Mon Sep 17 00:00:00 2001
From: Kovid Goyal <kovid@kovidgoyal.net>
Date: Sun, 29 Jun 2014 08:48:53 +0530
Subject: [PATCH] Fix #1335468 [Editor: ValueError: No JSON object could be
 decoded](https://bugs.launchpad.net/calibre/+bug/1335468)

---
 src/calibre/gui2/tweak_book/live_css.py | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/src/calibre/gui2/tweak_book/live_css.py b/src/calibre/gui2/tweak_book/live_css.py
index 8144948290..08a547efed 100644
--- a/src/calibre/gui2/tweak_book/live_css.py
+++ b/src/calibre/gui2/tweak_book/live_css.py
@@ -409,7 +409,10 @@ class LiveCSS(QWidget):
         result = unicode(mf.evaluateJavaScript(
             'window.calibre_preview_integration.live_css(%s, %s)' % (
                 json.dumps(sourceline), json.dumps(tags))).toString())
-        result = json.loads(result)
+        try:
+            result = json.loads(result)
+        except ValueError:
+            result = None
         if result is not None:
             maximum_specificities = {}
             for node in result['nodes']: