From 2d2673f61386672f3971fc76bb0f03c05ec0ece2 Mon Sep 17 00:00:00 2001
From: Zanie Blue <contact@zanie.dev>
Date: Wed, 26 Jul 2023 14:55:05 -0500
Subject: [PATCH] Add comment regarding class scope short circuit (#6101)

---
 crates/ruff_python_semantic/src/model.rs | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/crates/ruff_python_semantic/src/model.rs b/crates/ruff_python_semantic/src/model.rs
index 1c52a856c3..b316249fb3 100644
--- a/crates/ruff_python_semantic/src/model.rs
+++ b/crates/ruff_python_semantic/src/model.rs
@@ -313,6 +313,20 @@ impl<'a> SemanticModel<'a> {
                 if seen_function && matches!(symbol, "__class__") {
                     return ReadResult::ImplicitGlobal;
                 }
+                // Do not allow usages of class symbols unless it is the immediate parent, e.g.:
+                //
+                // ```python
+                // class Foo:
+                //      a = 0
+                //
+                //      b = a  # allowed
+                //      def c(self, arg=a):  # allowed
+                //          print(arg)
+                //
+                //      def d(self):
+                //          print(a)  # not allowed
+                // ```
+                //
                 if index > 0 {
                     continue;
                 }