From 890868380ae908807f34b0be1606e57c00976d7e Mon Sep 17 00:00:00 2001
From: 1ndahous3 <9205230+1ndahous3@users.noreply.github.com>
Date: Sun, 18 Oct 2026 11:41:55 +0300
Subject: [PATCH] Accept bytes-like input in pyexpat.Parse

Assisted-by: Codex:GPT-6
---
 crates/stdlib/src/pyexpat.rs           | 11 ++++-------
 extra_tests/snippets/stdlib_pyexpat.py | 27 ++++++++++++++++++++++++++
 2 files changed, 31 insertions(+), 7 deletions(-)

diff --git a/crates/stdlib/src/pyexpat.rs b/crates/stdlib/src/pyexpat.rs
index 724fdb75926..2ca962e924f 100644
--- a/crates/stdlib/src/pyexpat.rs
+++ b/crates/stdlib/src/pyexpat.rs
@@ -168,9 +168,9 @@ mod _pyexpat {
     use crate::vm::{
         AsObject, Context, Py, PyObjectRef, PyPayload, PyRef, PyResult, TryFromObject,
         VirtualMachine,
-        builtins::{PyBytesRef, PyException, PyModule, PyStr, PyStrRef, PyType, PyUtf8StrRef},
+        builtins::{PyException, PyModule, PyStr, PyStrRef, PyType, PyUtf8StrRef},
         extend_module,
-        function::{ArgBytesLike, Either, IntoFuncArgs, OptionalArg, OptionalOption},
+        function::{ArgBytesLike, ArgStrOrBytesLike, IntoFuncArgs, OptionalArg, OptionalOption},
         types::Constructor,
     };
     use alloc::collections::VecDeque;
@@ -1403,14 +1403,11 @@ mod _pyexpat {
         #[pymethod(name = "Parse")]
         fn parse(
             zelf: &Py<Self>,
-            data: Either<PyStrRef, PyBytesRef>,
+            data: ArgStrOrBytesLike,
             isfinal: OptionalArg<bool>,
             vm: &VirtualMachine,
         ) -> PyResult<i32> {
-            let bytes = match data {
-                Either::A(s) => s.as_bytes().to_vec(),
-                Either::B(b) => b.as_bytes().to_vec(),
-            };
+            let bytes = data.borrow_bytes().to_vec();
             zelf.feed(vm, &bytes, isfinal.unwrap_or(false))?;
             Ok(1)
         }
diff --git a/extra_tests/snippets/stdlib_pyexpat.py b/extra_tests/snippets/stdlib_pyexpat.py
index e8e2652d3db..512a4a529d8 100644
--- a/extra_tests/snippets/stdlib_pyexpat.py
+++ b/extra_tests/snippets/stdlib_pyexpat.py
@@ -21,3 +21,30 @@
             else {expected_attribute: "v", "a": "u"}
         )
         assert starts[1][1] == expected_attributes
+
+# Parse accepts contiguous buffer objects, including views of mutable input.
+for xml in (bytearray(b"<r>ok</r>"), memoryview(b"<r>ok</r>")):
+    parser = expat.ParserCreate()
+    text = []
+    parser.CharacterDataHandler = text.append
+    assert parser.Parse(xml, True) == 1
+    assert "".join(text) == "ok"
+
+try:
+    expat.ParserCreate().Parse(memoryview(b"<r/>")[::2], True)
+except BufferError:
+    pass
+else:
+    raise AssertionError("Parse accepted a non-contiguous buffer")
+
+# Keep the export alive through callbacks without retaining its read lock.
+xml = bytearray(b"<r/>")
+parser = expat.ParserCreate()
+parser.StartElementHandler = lambda *_: xml.extend(b" ")
+try:
+    parser.Parse(xml, True)
+except BufferError:
+    pass
+else:
+    raise AssertionError("Parse released its input buffer before the callback")
+xml.extend(b" ")