Fix TextIOWrapper.reconfigure coder

Author: youknowone

vm/src/stdlib/io.rs

@@ -2229,32 +2229,7 @@ mod _io {
             let has_read1 = vm.get_attribute_opt(buffer.clone(), "read1")?.is_some();
             let seekable = vm.call_method(&buffer, "seekable", ())?.try_to_bool(vm)?;
 
-            let codec = vm.state.codec_registry.lookup(encoding.as_str(), vm)?;
-
-            let encoder = if vm.call_method(&buffer, "writable", ())?.try_to_bool(vm)? {
-                let incremental_encoder =
-                    codec.get_incremental_encoder(Some(errors.clone()), vm)?;
-                let encoding_name = vm.get_attribute_opt(incremental_encoder.clone(), "name")?;
-                let encodefunc = encoding_name.and_then(|name| {
-                    let name = name.payload::<PyStr>()?;
-                    match name.as_str() {
-                        "utf-8" => Some(textio_encode_utf8 as EncodeFunc),
-                        _ => None,
-                    }
-                });
-                Some((incremental_encoder, encodefunc))
-            } else {
-                None
-            };
-
-            let decoder = if vm.call_method(&buffer, "readable", ())?.try_to_bool(vm)? {
-                let incremental_decoder =
-                    codec.get_incremental_decoder(Some(errors.clone()), vm)?;
-                // TODO: wrap in IncrementalNewlineDecoder if newlines == Universal | Passthrough
-                Some(incremental_decoder)
-            } else {
-                None
-            };
+            let (encoder, decoder) = Self::find_coder(&buffer, encoding.as_str(), &errors, vm)?;
 
             *data = Some(TextIOData {
                 buffer,
@@ -2296,16 +2271,59 @@ mod _io {
             PyThreadMutexGuard::try_map(lock, |x| x.as_mut())
                 .map_err(|_| vm.new_value_error("I/O operation on uninitialized object".to_owned()))
         }
+
+        #[allow(clippy::type_complexity)]
+        fn find_coder(
+            buffer: &PyObject,
+            encoding: &str,
+            errors: &Py<PyStr>,
+            vm: &VirtualMachine,
+        ) -> PyResult<(
+            Option<(PyObjectRef, Option<EncodeFunc>)>,
+            Option<PyObjectRef>,
+        )> {
+            let codec = vm.state.codec_registry.lookup(encoding, vm)?;
+
+            let encoder = if vm.call_method(buffer, "writable", ())?.try_to_bool(vm)? {
+                let incremental_encoder =
+                    codec.get_incremental_encoder(Some(errors.to_owned()), vm)?;
+                let encoding_name = vm.get_attribute_opt(incremental_encoder.clone(), "name")?;
+                let encodefunc = encoding_name.and_then(|name| {
+                    let name = name.payload::<PyStr>()?;
+                    match name.as_str() {
+                        "utf-8" => Some(textio_encode_utf8 as EncodeFunc),
+                        _ => None,
+                    }
+                });
+                Some((incremental_encoder, encodefunc))
+            } else {
+                None
+            };
+
+            let decoder = if vm.call_method(buffer, "readable", ())?.try_to_bool(vm)? {
+                let incremental_decoder =
+                    codec.get_incremental_decoder(Some(errors.to_owned()), vm)?;
+                // TODO: wrap in IncrementalNewlineDecoder if newlines == Universal | Passthrough
+                Some(incremental_decoder)
+            } else {
+                None
+            };
+            Ok((encoder, decoder))
+        }
     }
 
     #[pyclass(with(Constructor, Initializer), flags(BASETYPE))]
     impl TextIOWrapper {
         #[pymethod]
-        fn reconfigure(&self, args: TextIOWrapperArgs) {
+        fn reconfigure(&self, args: TextIOWrapperArgs, vm: &VirtualMachine) -> PyResult<()> {
             let mut data = self.data.lock().unwrap();
             if let Some(data) = data.as_mut() {
                 if let Some(encoding) = args.encoding {
+                    let (encoder, decoder) =
+                        Self::find_coder(&data.buffer, encoding.as_str(), &data.errors, vm)?;
                     data.encoding = encoding;
+                    data.encoder = encoder;
+                    data.decoder = decoder;
                 }
                 if let Some(errors) = args.errors {
                     data.errors = errors;
@@ -2320,6 +2338,7 @@ mod _io {
                     data.write_through = write_through;
                 }
             }
+            Ok(())
         }
         #[pymethod]
         fn seekable(&self, vm: &VirtualMachine) -> PyResult {