From 87eb1fb16437a36c6de477be2dd448140a7362b6 Mon Sep 17 00:00:00 2001
From: Charles Haley <cbhaley@i.wont.say.com>
Date: Sat, 12 Dec 2020 22:16:04 +0000
Subject: [PATCH] Bug #1907856: Typing in number fails to replace undefined
 integers

---
 src/calibre/gui2/library/delegates.py | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/calibre/gui2/library/delegates.py b/src/calibre/gui2/library/delegates.py
index a2f679e475..0be684247e 100644
--- a/src/calibre/gui2/library/delegates.py
+++ b/src/calibre/gui2/library/delegates.py
@@ -145,6 +145,8 @@ def make_clearing_spinbox(spinbox):
             if ev.key() == Qt.Key.Key_Space:
                 self.clear_to_undefined()
             else:
+                if self.value() == self.minimum():
+                    self.clear()
                 return spinbox.keyPressEvent(self, ev)
     return SpinBox