Issue #25766: Special method __bytes__() now works in str subclasses.

1 files changed, 12 insertions, 6 deletions

diff --git a/Objects/bytesobject.c b/Objects/bytesobject.c
index cbdac86aec..3cc7ce34d0 100644
--- a/Objects/bytesobject.c
+++ b/Objects/bytesobject.c
@@ -3320,11 +3320,11 @@ bytes_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
         return PyBytes_FromStringAndSize(NULL, 0);
     }
 
-    if (PyUnicode_Check(x)) {
+    if (encoding != NULL) {
         /* Encode via the codec registry */
-        if (encoding == NULL) {
+        if (!PyUnicode_Check(x)) {
             PyErr_SetString(PyExc_TypeError,
-                            "string argument without an encoding");
+                            "encoding without a string argument");
             return NULL;
         }
         new = PyUnicode_AsEncodedString(x, encoding, errors);
@@ -3334,10 +3334,11 @@ bytes_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
         return new;
     }
 
-    /* If it's not unicode, there can't be encoding or errors */
-    if (encoding != NULL || errors != NULL) {
+    if (errors != NULL) {
         PyErr_SetString(PyExc_TypeError,
-            "encoding or errors without a string argument");
+                        PyUnicode_Check(x) ?
+                        "string argument without an encoding" :
+                        "errors without a string argument");
         return NULL;
     }
 
@@ -3362,6 +3363,11 @@ bytes_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
     else if (PyErr_Occurred())
         return NULL;
 
+    if (PyUnicode_Check(x)) {
+        PyErr_SetString(PyExc_TypeError,
+                        "string argument without an encoding");
+        return NULL;
+    }
     /* Is it an integer? */
     size = PyNumber_AsSsize_t(x, PyExc_OverflowError);
     if (size == -1 && PyErr_Occurred()) {