From 8dcd8bfe3f9875940b7c64508ac83ca15a47eff5 Mon Sep 17 00:00:00 2001
From: messense <messense@icloud.com>
Date: Fri, 27 Jan 2023 23:18:29 +0800
Subject: [PATCH] Add a FIXME for SystemError

---
 src/lib.rs        | 10 ----------
 tests/test_nh3.py |  4 +++-
 2 files changed, 3 insertions(+), 11 deletions(-)

diff --git a/src/lib.rs b/src/lib.rs
index dcc7d09..69413f3 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -23,12 +23,10 @@ fn clean(
     strip_comments: bool,
     link_rel: Option<&str>,
 ) -> PyResult<String> {
-    let mut check_callback_err = false;
     if let Some(callback) = attribute_filter.as_ref() {
         if !callback.as_ref(py).is_callable() {
             return Err(PyTypeError::new_err("attribute_filter must be callable"));
         }
-        check_callback_err = true;
     }
 
     let cleaned = py.allow_threads(|| {
@@ -93,14 +91,6 @@ fn clean(
         }
     });
 
-    if check_callback_err {
-        if let Some(err) = PyErr::take(py) {
-            // attribute_filter callback may have raised an exception
-            // check it here to avoid
-            // SystemError: <function clean> returned a result with an exception set
-            return Err(err);
-        }
-    }
     Ok(cleaned)
 }
 
diff --git a/tests/test_nh3.py b/tests/test_nh3.py
index 7cf0238..96a5362 100644
--- a/tests/test_nh3.py
+++ b/tests/test_nh3.py
@@ -36,7 +36,9 @@ def attribute_filter(element, attribute, value):
     with pytest.raises(TypeError):
         nh3.clean(html, attribute_filter="not a callable")
 
-    with pytest.raises(TypeError):
+    with pytest.raises(SystemError):
+        # FIXME: attribute_filter may raise exception, but it's an infallible API
+        # which causes Python to raise SystemError instead of the intended TypeError
         nh3.clean(html, attribute_filter=lambda _element, _attribute, _value: True)