Match Element.remove argument type diagnostics (#9068)

Match native type names, None spelling, and UTF-8 byte limits while preserving removal behavior. Keep all six regression cases in the existing XML snippet.

Assisted-by: OpenAI Codex:model identifier unavailable

crates/stdlib/src/elementtree.rs

@@ -578,7 +578,21 @@ pub(crate) mod _elementtree {
 
         #[pymethod]
         fn remove(zelf: &Py<Self>, subelement: PyObjectRef, vm: &VirtualMachine) -> PyResult<()> {
-            check_element(&subelement, vm)?;
+            if !subelement.downcastable::<Self>() {
+                let name = if vm.is_none(&subelement) {
+                    "None".into()
+                } else {
+                    subelement.class().slot_name()
+                };
+                let mut end = name.len().min(50);
+                while !name.is_char_boundary(end) {
+                    end -= 1;
+                }
+                return Err(vm.new_type_error(format!(
+                    "remove() argument must be xml.etree.ElementTree.Element, not {}",
+                    &name[..end]
+                )));
+            }
             // Identity first, then equality, the way `element_remove` does;
             // the equality test can run arbitrary code, so the lock is
             // dropped for it and the list re-read afterwards.

extra_tests/snippets/stdlib_xml.py

@@ -1,4 +1,6 @@
+import array
 import xml.sax
+from xml.etree.ElementTree import Element
 from xml.parsers import expat
 
 from testutils import assert_raises
@@ -66,3 +68,18 @@ assert events == [
     ("characters", "text"),
     ("end-cdata",),
 ]
+
+root = Element("root")
+for value, type_name in (
+    (None, "None"),
+    (1, "int"),
+    ("child", "str"),
+    (array.array("b"), "array.array"),
+    (type("A" * 60, (), {})(), "A" * 50),
+    (type("€" * 20, (), {})(), "€" * 16),
+):
+    with assert_raises(TypeError) as caught:
+        root.remove(value)
+    assert str(caught.exception) == (
+        "remove() argument must be xml.etree.ElementTree.Element, not " + type_name
+    )