From e07fc77a529b1787e9de6210d3e1b56d7569ed27 Mon Sep 17 00:00:00 2001
From: Kovid Goyal <kovid@kovidgoyal.net>
Date: Wed, 18 Feb 2015 13:18:26 +0530
Subject: [PATCH] Edit Book: Reports tool: Fix double clicking on an unused
 image causing an error

---
 src/calibre/gui2/tweak_book/reports.py | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/src/calibre/gui2/tweak_book/reports.py b/src/calibre/gui2/tweak_book/reports.py
index dd397a75ac..0f7b9ef528 100644
--- a/src/calibre/gui2/tweak_book/reports.py
+++ b/src/calibre/gui2/tweak_book/reports.py
@@ -336,9 +336,10 @@ class Jump(object):
         self.pos_map.clear()
 
     def __call__(self, key, locations):
-        self.pos_map[key] = (self.pos_map[key] + 1) % len(locations)
-        loc = locations[self.pos_map[key]]
-        jump_to_location(loc)
+        if len(locations):
+            self.pos_map[key] = (self.pos_map[key] + 1) % len(locations)
+            loc = locations[self.pos_map[key]]
+            jump_to_location(loc)
 
 jump = Jump()  # }}}