@@ -250,7 +250,7 @@ def read(self, filename, strict=True):
         list of standard types, else to the list of non-standard
         types.
         """
-        with open(filename, encoding='utf-8') as fp:
+        with open(filename, encoding='utf-8', errors='surrogateescape') as fp:
             self.readfp(fp, strict)
 
     def readfp(self, fp, strict=True):
@@ -444,7 +444,7 @@ def init(files=None):
 
 def read_mime_types(file):
     try:
-        f = open(file, encoding='utf-8')
+        f = open(file, encoding='utf-8', errors='surrogateescape')
     except OSError:
         return None
     with f:
 
@@ -232,3 +232,23 @@ def reset_worker():
                 decoder.reset()
 
         run_concurrently([decode_worker] * 2 + [reset_worker] * 2)
+
+
+class TextIOWrapperTest(TestCase):
+    def test_buffer_detach_race(self):
+        make = lambda: io.TextIOWrapper(io.BytesIO())
+        slot = [make()]
+
+        def reader():
+            for _ in range(1000):
+                try:
+                    slot[0].buffer
+                except ValueError:
+                    pass
+
+        def detacher():
+            for _ in range(1000):
+                slot[0] = make()
+                slot[0].detach()
+
+        run_concurrently([reader, detacher])
@@ -67,9 +67,50 @@ def test_read_mime_types(self):
         with unittest.mock.patch.object(mimetypes, 'open',
                                         return_value=fp) as mock_open:
             mime_dict = mimetypes.read_mime_types(filename)
-            mock_open.assert_called_with(filename, encoding='utf-8')
+            mock_open.assert_called_with(filename, encoding='utf-8',
+                                         errors='surrogateescape')
         eq(mime_dict[".Français"], "application/no-mans-land")
 
+    def test_read_mime_types_invalid_utf8_comment(self):
+        with os_helper.temp_dir() as directory:
+            data = (b"# non-UTF-8 comment: \x83\n"
+                    b"x-application/x-unittest pyunit\n")
+            file = os.path.join(directory, "sample.mimetype")
+            with open(file, "wb") as f:
+                f.write(data)
+
+            mime_dict = mimetypes.read_mime_types(file)
+            self.assertEqual(
+                mime_dict[".pyunit"], "x-application/x-unittest")
+
+            db = mimetypes.MimeTypes()
+            db.read(file)
+            self.assertEqual(
+                db.guess_file_type("sample.pyunit")[0],
+                "x-application/x-unittest")
+
+            mimetypes.init(files=[file])
+            self.assertEqual(
+                mimetypes.guess_file_type("sample.pyunit")[0],
+                "x-application/x-unittest")
+
+    def test_read_mime_types_invalid_utf8_type(self):
+        # A non-UTF-8 byte in a type or extension (not only in a comment) is
+        # preserved via surrogateescape, so the mapping is not corrupted.
+        with os_helper.temp_dir() as directory:
+            data = (b"x-application/x-unittest pyunit\n"
+                    b"application/bad\x83 badext\x83\n")
+            file = os.path.join(directory, "sample.mimetype")
+            with open(file, "wb") as f:
+                f.write(data)
+
+            bad_type = b"application/bad\x83".decode("utf-8", "surrogateescape")
+            bad_ext = b".badext\x83".decode("utf-8", "surrogateescape")
+
+            mime_dict = mimetypes.read_mime_types(file)
+            self.assertEqual(mime_dict[".pyunit"], "x-application/x-unittest")
+            self.assertEqual(mime_dict[bad_ext], bad_type)
+
     def test_init_reinitializes(self):
         # Issue 4936: make sure an init starts clean
         # First, put some poison into the types table
 
@@ -0,0 +1,2 @@
+Fix :mod:`mimetypes` initialization from MIME map files containing invalid
+UTF-8 bytes.
@@ -0,0 +1,2 @@
+Fixed data-race when calling :meth:`io.TextIOBase.detach` in
+:term:`free-threaded build`.
@@ -3424,6 +3424,19 @@ _io_TextIOWrapper__CHUNK_SIZE_set_impl(textio *self, PyObject *value)
     return 0;
 }
 
+/*[clinic input]
+@critical_section
+@getter
+_io.TextIOWrapper.buffer
+[clinic start generated code]*/
+
+static PyObject *
+_io_TextIOWrapper_buffer_get_impl(textio *self)
+/*[clinic end generated code: output=d265a34555aa5d4b input=5951cfa148f7350a]*/
+{
+    return Py_XNewRef(buffer_access_safe(self));
+}
+
 static PyMethodDef incrementalnewlinedecoder_methods[] = {
     _IO_INCREMENTALNEWLINEDECODER_DECODE_METHODDEF
     _IO_INCREMENTALNEWLINEDECODER_GETSTATE_METHODDEF
@@ -3482,7 +3495,6 @@ static PyMethodDef textiowrapper_methods[] = {
 
 static PyMemberDef textiowrapper_members[] = {
     {"encoding", _Py_T_OBJECT, offsetof(textio, encoding), Py_READONLY},
-    {"buffer", _Py_T_OBJECT, offsetof(textio, buffer), Py_READONLY},
     {"line_buffering", Py_T_BOOL, offsetof(textio, line_buffering), Py_READONLY},
     {"write_through", Py_T_BOOL, offsetof(textio, write_through), Py_READONLY},
     {"_finalizing", Py_T_BOOL, offsetof(textio, finalizing), 0},
@@ -3497,6 +3509,7 @@ static PyGetSetDef textiowrapper_getset[] = {
     _IO_TEXTIOWRAPPER_NEWLINES_GETSETDEF
     _IO_TEXTIOWRAPPER_ERRORS_GETSETDEF
     _IO_TEXTIOWRAPPER__CHUNK_SIZE_GETSETDEF
+    _IO_TEXTIOWRAPPER_BUFFER_GETSETDEF
     {NULL}
 };
 
 
@@ -1,7 +1,7 @@
 # Any data that can vary between Python versions is to be kept in this file.
 # This allows for blanket copying of the Emscripten build code between supported
 # Python versions.
-emscripten-version = "6.0.4"
+emscripten-version = "6.0.5"
 node-version = "24"
 test-args = [
     "-m", "test",
Original file line number	Diff line number	Diff line change
@@ -0,0 +1,2 @@
	1	+ Fix :mod:`mimetypes` initialization from MIME map files containing invalid
	2	+ UTF-8 bytes.
Original file line number	Diff line number	Diff line change
@@ -0,0 +1,2 @@
	1	+ Fixed data-race when calling :meth:`io.TextIOBase.detach` in
	2	+ :term:`free-threaded build`.