From c73353064f934ae49472eb6138e1f8071b6b733e Mon Sep 17 00:00:00 2001
From: Joe Young <80432516+jpy-git@users.noreply.github.com>
Date: Mon, 28 Mar 2022 10:27:32 +0100
Subject: [PATCH] `unnecessary-ellipsis` false positive: allow ellipsis as
 default argument (#6007)

---
 ChangeLog                                              | 4 ++++
 doc/whatsnew/2.13.rst                                  | 4 ++++
 pylint/checkers/ellipsis_checker.py                    | 5 ++++-
 tests/functional/u/unnecessary/unnecessary_ellipsis.py | 6 +++++-
 4 files changed, 17 insertions(+), 2 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 22fe55cae5..ef8c38843f 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -20,6 +20,10 @@ What's New in Pylint 2.13.3?
 ============================
 Release date: TBA
 
+* Fix false positive for ``unnecessary-ellipsis`` when using an ellipsis as a default argument.
+
+  Closes #5973
+
 * Fix crash involving unbalanced tuple unpacking.
 
   Closes #5998
diff --git a/doc/whatsnew/2.13.rst b/doc/whatsnew/2.13.rst
index 2d425d7a4a..b2c40e87e0 100644
--- a/doc/whatsnew/2.13.rst
+++ b/doc/whatsnew/2.13.rst
@@ -128,6 +128,10 @@ Extensions
 Other Changes
 =============
 
+* Fix false positive for ``unnecessary-ellipsis`` when using an ellipsis as a default argument.
+
+  Closes #5973
+
 * Add missing dunder methods to ``unexpected-special-method-signature`` check.
 
 * No longer emit ``no-member`` in for loops that reference ``self`` if the binary operation that
diff --git a/pylint/checkers/ellipsis_checker.py b/pylint/checkers/ellipsis_checker.py
index 2d904a28d2..ac5e04095e 100644
--- a/pylint/checkers/ellipsis_checker.py
+++ b/pylint/checkers/ellipsis_checker.py
@@ -41,7 +41,10 @@ def visit_const(self, node: nodes.Const) -> None:
         """
         if (
             node.pytype() == "builtins.Ellipsis"
-            and not isinstance(node.parent, (nodes.Assign, nodes.AnnAssign, nodes.Call))
+            and not isinstance(
+                node.parent,
+                (nodes.Assign, nodes.AnnAssign, nodes.Call, nodes.Arguments),
+            )
             and (
                 len(node.parent.parent.child_sequence(node.parent)) > 1
                 or (
diff --git a/tests/functional/u/unnecessary/unnecessary_ellipsis.py b/tests/functional/u/unnecessary/unnecessary_ellipsis.py
index b5a61e3493..1a6ed777c2 100644
--- a/tests/functional/u/unnecessary/unnecessary_ellipsis.py
+++ b/tests/functional/u/unnecessary/unnecessary_ellipsis.py
@@ -1,6 +1,6 @@
 """Emit a warning when the ellipsis constant is used and can be avoided"""
 
-# pylint: disable=missing-docstring, too-few-public-methods
+# pylint: disable=missing-docstring, too-few-public-methods, invalid-name, unused-argument
 
 from typing import List, overload, Union
 
@@ -97,3 +97,7 @@ def __getitem__(self, index: Union[int, slice]) -> Union[int, List[int]]:
             ...
         else:
             raise TypeError(...)
+
+# Ellipsis is allowed as a default argument
+def func_with_ellipsis_default_arg(a = ...) -> None:
+    "Some docstring."