undoing change to pybind11::str::raw_str, adjusting test_pybind11_str_raw_str to match behavior after changing detail::PyUnicode_Check_Permissive to PyUnicode_Check'

Author: rwgk

include/pybind11/pytypes.h

@@ -928,12 +928,12 @@ class str : public object {
 private:
     /// Return string representation -- always returns a new reference, even if already a str
     static PyObject *raw_str(PyObject *op) {
-#if PY_MAJOR_VERSION < 3
-        PyObject *str_value = PyObject_Unicode(op);
-#else
         PyObject *str_value = PyObject_Str(op);
-#endif
         if (!str_value) throw error_already_set();
+#if PY_MAJOR_VERSION < 3
+        PyObject *unicode = PyUnicode_FromEncodedObject(str_value, "utf-8", nullptr);
+        Py_XDECREF(str_value); str_value = unicode;
+#endif
         return str_value;
     }
 };

tests/test_pytypes.py

@@ -251,15 +251,24 @@ def test_pybind11_str_raw_str():
     assert cvt(set()) == u"set([])" if str is bytes else "set()"
     assert cvt({3, 3}) == u"set([3])" if str is bytes else "{3}"
 
-    valid_utf8 = u"DZ".encode("utf-8")
+    valid_orig = u"DZ"
+    valid_utf8 = valid_orig.encode("utf-8")
     valid_cvt = cvt(valid_utf8)
-    assert type(valid_cvt) == bytes  # Probably surprising.
-    assert valid_cvt == b'\xc7\xb1'
+    assert type(valid_cvt) == type(u"")  # Py2 unicode, Py3 str, flake8 compatible
+    if str is bytes:
+        assert valid_cvt == valid_orig
+    else:
+        assert valid_cvt == u"b'\\xc7\\xb1'"
 
     malformed_utf8 = b'\x80'
-    malformed_cvt = cvt(malformed_utf8)
-    assert type(malformed_cvt) == bytes  # Probably surprising.
-    assert malformed_cvt == b'\x80'
+    if str is bytes:
+        with pytest.raises(UnicodeDecodeError) as excinfo:
+            cvt(malformed_utf8)
+        assert "invalid start byte" in str(excinfo)
+    else:
+        malformed_cvt = cvt(malformed_utf8)
+        assert type(valid_cvt) == type(u"")
+        assert malformed_cvt == u"b'\\x80'"
 
 
 def test_implicit_casting():