gh-94521: Copy or cut current line while no selection

Lib/idlelib/editor.py

@@ -605,13 +605,16 @@ def python_docs(self, event=None):
         return "break"
 
     def cut(self,event):
+        if not self.text.tag_ranges('sel'):
+            self.text.tag_add('sel', 'insert linestart', 'insert+1l linestart')
+            self.text.mark_set('insert', 'insert linestart')
         self.text.event_generate("<<Cut>>")
         return "break"
 
     def copy(self,event):
         if not self.text.tag_ranges("sel"):
-            # There is no selection, so do nothing and maybe interrupt.
-            return None
+            self.text.tag_add('sel', 'insert linestart', 'insert+1l linestart')
+            self.text.mark_set('insert', 'insert linestart')
         self.text.event_generate("<<Copy>>")
         return "break"
 

Misc/NEWS.d/next/IDLE/2026-02-23-17-28-34.gh-issue-94521.vlr8XB.rst

@@ -0,0 +1 @@
+Copy or cut the current line when no text is selected in IDLE. Patch by Shixian Li.