From a4464ef292898246f201ce21b3d247ee38a64d3b Mon Sep 17 00:00:00 2001
From: Kovid Goyal <kovid@kovidgoyal.net>
Date: Fri, 26 May 2023 15:44:55 +0530
Subject: [PATCH] Fix #2020854 [local variable 'd' referenced before assignment
  calibre 6.18](https://bugs.launchpad.net/calibre/+bug/2020854)

---
 src/calibre/gui2/cover_flow.py | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/calibre/gui2/cover_flow.py b/src/calibre/gui2/cover_flow.py
index b662f2e55f..b088d6da47 100644
--- a/src/calibre/gui2/cover_flow.py
+++ b/src/calibre/gui2/cover_flow.py
@@ -231,6 +231,7 @@ class CoverFlow(pictureflow.PictureFlow):
         return self.minimumSize()
 
     def wheelEvent(self, ev):
+        d = 0
         if ev.angleDelta().x():
             d = ev.angleDelta().x()
         if ev.angleDelta().y():