From 00d2ee08de4fa21d36e7eba1cc321b19d9d83eb6 Mon Sep 17 00:00:00 2001
From: Mark Byrne <31762852+mbyrnepr2@users.noreply.github.com>
Date: Tue, 4 Jun 2024 23:54:57 +0200
Subject: [PATCH] Fix a false positive for ``redefined-outer-name`` (#9678)

When there is a name defined in an exception-handling block which shares the same name
as a local variable that has been defined in a function body. Check if the outer node is in the
scope of an exception assignment and do not emit ``redefined-outer-name`` if that is the case.

Closes #9671

(cherry picked from commit 57ae027efcd9bc19d793459fc15904cb9c45578a)
---
 doc/whatsnew/fragments/9671.false_positive    |  3 +++
 pylint/checkers/variables.py                  |  9 ++++++++
 .../r/redefined/redefined_except_handler.py   | 22 +++++++++++++++++++
 3 files changed, 34 insertions(+)
 create mode 100644 doc/whatsnew/fragments/9671.false_positive

diff --git a/doc/whatsnew/fragments/9671.false_positive b/doc/whatsnew/fragments/9671.false_positive
new file mode 100644
index 0000000000..23dafff10f
--- /dev/null
+++ b/doc/whatsnew/fragments/9671.false_positive
@@ -0,0 +1,3 @@
+Fix a false positive for ``redefined-outer-name`` when there is a name defined in an exception-handling block which shares the same name as a local variable that has been defined in a function body.
+
+Closes #9671
diff --git a/pylint/checkers/variables.py b/pylint/checkers/variables.py
index 6c33a05556..8447320b89 100644
--- a/pylint/checkers/variables.py
+++ b/pylint/checkers/variables.py
@@ -1519,6 +1519,15 @@ def visit_functiondef(self, node: nodes.FunctionDef) -> None:
                 ):
                     continue
 
+                # Suppress emitting the message if the outer name is in the
+                # scope of an exception assignment.
+                # For example: the `e` in `except ValueError as e`
+                global_node = globs[name][0]
+                if isinstance(global_node, nodes.AssignName) and isinstance(
+                    global_node.parent, nodes.ExceptHandler
+                ):
+                    continue
+
                 line = definition.fromlineno
                 if not self._is_name_ignored(stmt, name):
                     self.add_message(
diff --git a/tests/functional/r/redefined/redefined_except_handler.py b/tests/functional/r/redefined/redefined_except_handler.py
index b774e32f2f..d621496263 100644
--- a/tests/functional/r/redefined/redefined_except_handler.py
+++ b/tests/functional/r/redefined/redefined_except_handler.py
@@ -70,3 +70,25 @@ def func():
     # pylint:disable-next=invalid-name, unused-variable
     except IOError as CustomException:  # [redefined-outer-name]
         pass
+
+
+# https://github.com/pylint-dev/pylint/issues/9671
+def function_before_exception():
+    """The local variable `e` should not trigger `redefined-outer-name`
+       when `e` is also defined in the subsequent exception handling block.
+    """
+    e = 42
+    return e
+
+try:
+    raise ValueError('outer')
+except ValueError as e:
+    print(e)
+
+
+def function_after_exception():
+    """The local variable `e` should not trigger `redefined-outer-name`
+       when `e` is also defined in the preceding exception handling block.
+    """
+    e = 42
+    return e