From 7708c1e18fd23a8f59dddcfdac9312bd0b5125a5 Mon Sep 17 00:00:00 2001
From: Inada Naoki <songofacandy@gmail.com>
Date: Fri, 2 Apr 2021 16:20:43 +0900
Subject: [PATCH] bpo-43510: Fix emitting EncodingWarning from _io module.

I forget to check PyErr_WarnEx() return value. But it will fail when -Werror is used.
---
 Modules/_io/_iomodule.c |  6 ++++--
 Modules/_io/textio.c    | 24 +++++++++++++-----------
 2 files changed, 17 insertions(+), 13 deletions(-)

diff --git a/Modules/_io/_iomodule.c b/Modules/_io/_iomodule.c
index 652c2ce5b0d61f..170dea41e8abdd 100644
--- a/Modules/_io/_iomodule.c
+++ b/Modules/_io/_iomodule.c
@@ -532,8 +532,10 @@ _io_text_encoding_impl(PyObject *module, PyObject *encoding, int stacklevel)
     if (encoding == NULL || encoding == Py_None) {
         PyInterpreterState *interp = _PyInterpreterState_GET();
         if (_PyInterpreterState_GetConfig(interp)->warn_default_encoding) {
-            PyErr_WarnEx(PyExc_EncodingWarning,
-                         "'encoding' argument not specified", stacklevel);
+            if (PyErr_WarnEx(PyExc_EncodingWarning,
+                             "'encoding' argument not specified", stacklevel)) {
+                return NULL;
+            }
         }
         Py_INCREF(_PyIO_str_locale);
         return _PyIO_str_locale;
diff --git a/Modules/_io/textio.c b/Modules/_io/textio.c
index 6f89a879c9c2bf..eb05ae1a16eb03 100644
--- a/Modules/_io/textio.c
+++ b/Modules/_io/textio.c
@@ -1085,6 +1085,19 @@ _io_TextIOWrapper___init___impl(textio *self, PyObject *buffer,
     self->ok = 0;
     self->detached = 0;
 
+    if (encoding == NULL) {
+        PyInterpreterState *interp = _PyInterpreterState_GET();
+        if (_PyInterpreterState_GetConfig(interp)->warn_default_encoding) {
+            if (PyErr_WarnEx(PyExc_EncodingWarning,
+                             "'encoding' argument not specified", 1)) {
+                return -1;
+            }
+        }
+    }
+    else if (strcmp(encoding, "locale") == 0) {
+        encoding = NULL;
+    }
+
     if (errors == Py_None) {
         errors = _PyUnicode_FromId(&PyId_strict); /* borrowed */
         if (errors == NULL) {
@@ -1123,17 +1136,6 @@ _io_TextIOWrapper___init___impl(textio *self, PyObject *buffer,
     self->encodefunc = NULL;
     self->b2cratio = 0.0;
 
-    if (encoding == NULL) {
-        PyInterpreterState *interp = _PyInterpreterState_GET();
-        if (_PyInterpreterState_GetConfig(interp)->warn_default_encoding) {
-            PyErr_WarnEx(PyExc_EncodingWarning,
-                         "'encoding' argument not specified", 1);
-        }
-    }
-    else if (strcmp(encoding, "locale") == 0) {
-        encoding = NULL;
-    }
-
     if (encoding == NULL) {
         /* Try os.device_encoding(fileno) */
         PyObject *fileno;