From 8ca39776024293c70686d7a519de880364bc44bd Mon Sep 17 00:00:00 2001
From: Arne de Laat <arne@delaat.net>
Date: Sun, 21 May 2023 17:49:53 +0200
Subject: [PATCH] Fix false-positive for TRY302 if exception cause is given
 (#4559)

---
 .../resources/test/fixtures/tryceratops/TRY302.py    | 12 ++++++++++++
 .../rules/tryceratops/rules/useless_try_except.rs    |  2 +-
 2 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/crates/ruff/resources/test/fixtures/tryceratops/TRY302.py b/crates/ruff/resources/test/fixtures/tryceratops/TRY302.py
index 0020926e4d2f3..3691e5472afc5 100644
--- a/crates/ruff/resources/test/fixtures/tryceratops/TRY302.py
+++ b/crates/ruff/resources/test/fixtures/tryceratops/TRY302.py
@@ -68,6 +68,18 @@ def bad():
     except Exception as e:
         raise e
 
+def fine():
+    try:
+        process()
+    except Exception as e:
+        raise e from None
+
+def fine():
+    try:
+        process()
+    except Exception as e:
+        raise e from Exception
+
 def fine():
     try:
         process()
diff --git a/crates/ruff/src/rules/tryceratops/rules/useless_try_except.rs b/crates/ruff/src/rules/tryceratops/rules/useless_try_except.rs
index e2446ddc6d679..8869e4eccdc26 100644
--- a/crates/ruff/src/rules/tryceratops/rules/useless_try_except.rs
+++ b/crates/ruff/src/rules/tryceratops/rules/useless_try_except.rs
@@ -44,7 +44,7 @@ pub(crate) fn useless_try_except(checker: &mut Checker, handlers: &[Excepthandle
         .iter()
         .map(|handler| {
             let ExceptHandler(ExcepthandlerExceptHandler { name, body, .. }) = handler;
-            let Some(Stmt::Raise(ast::StmtRaise {  exc, .. })) = &body.first() else {
+            let Some(Stmt::Raise(ast::StmtRaise {  exc, cause: None, .. })) = &body.first() else {
                 return None;
             };
             if let Some(expr) = exc {