From 5b33fe688491ad8e8d426db0cc30f4a06164ac29 Mon Sep 17 00:00:00 2001
From: Kovid Goyal <kovid@kovidgoyal.net>
Date: Mon, 7 Sep 2020 08:38:02 +0530
Subject: [PATCH] Fix double clicking on chapter heading in highlights panel
 causing an exception

---
 src/calibre/gui2/viewer/highlights.py | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/calibre/gui2/viewer/highlights.py b/src/calibre/gui2/viewer/highlights.py
index 6519ca43ca..05fe825139 100644
--- a/src/calibre/gui2/viewer/highlights.py
+++ b/src/calibre/gui2/viewer/highlights.py
@@ -292,7 +292,9 @@ class Highlights(QTreeWidget):
         return False
 
     def item_activated(self, item):
-        self.jump_to_highlight.emit(item.data(0, Qt.UserRole))
+        h = item.data(0, Qt.UserRole)
+        if h is not None:
+            self.jump_to_highlight.emit(h)
 
     @property
     def current_highlight(self):