[3.14] gh-133400: Fixed Ctrl+D (^D) behavior in :mod:_pyrepl module (GH-133883) (GH-139850)

(cherry picked from commit 81959a0364)

Co-authored-by: DeepWzh <wzh2012@outlook.com>
Co-authored-by: adam j hartz <adam@smatz.net>

Lib/_pyrepl/commands.py

@@ -420,14 +420,17 @@ class delete(EditCommand):
     def do(self) -> None:
         r = self.reader
         b = r.buffer
-        if (
-            r.pos == 0
-            and len(b) == 0  # this is something of a hack
-            and self.event[-1] == "\004"
-        ):
-            r.update_screen()
-            r.console.finish()
-            raise EOFError
+        if self.event[-1] == "\004":
+            if b and b[-1].endswith("\n"):
+                self.finish = True
+            elif (
+                r.pos == 0
+                and len(b) == 0  # this is something of a hack
+            ):
+                r.update_screen()
+                r.console.finish()
+                raise EOFError
+
         for i in range(r.get_arg()):
             if r.pos != len(b):
                 del b[r.pos]