gh-75595: Do not save a blank int entry in IDLE Settings

Lib/idlelib/configdialog.py

@@ -2265,7 +2265,11 @@ def make_callback(var, config):
         "Return default callback function to add values to changes instance."
         def default_callback(*params):
             "Add config values to changes instance."
-            changes.add_option(*config, var.get())
+            value = var.get()
+            # A blanked int entry is an empty string; do not save it as an
+            # invalid config value (gh-83653).
+            if value != '':
+                changes.add_option(*config, value)
         return default_callback
 
     def attach(self):

Lib/idlelib/idle_test/test_configdialog.py

@@ -1544,6 +1544,17 @@ def test_make_callback(self):
         self.assertEqual(changes['main']['section']['option'], '42')
         changes.clear()
 
+        # gh-83653: a blank int entry is not saved as bad config data.
+        sv = StringVar(root)
+        cb = self.tracers.make_callback(sv, ('main', 'section', 'option'))
+        sv.set('')
+        cb()
+        self.assertNotIn('section', changes['main'])
+        sv.set('5')
+        cb()
+        self.assertEqual(changes['main']['section']['option'], '5')
+        changes.clear()
+
     def test_attach_detach(self):
         tr = self.tracers
         iv = tr.add(self.iv, self.var_changed_increment)

Misc/NEWS.d/next/IDLE/2026-07-01-18-00-00.gh-issue-83653.cFgInt.rst

@@ -0,0 +1,3 @@
+Blanking an integer entry in IDLE's Settings dialog, such as "Auto squeeze
+min lines", no longer saves an empty string as an invalid configuration
+value.