Set __qualname__ for py3 enums (PY >= 3.3)

Author: aldanor

include/pybind11/pybind11.h

@@ -1255,6 +1255,10 @@ class py3_enum {
                 kwargs["module"] = scope.attr("__module__");
             else if (hasattr(scope, "__name__"))
                 kwargs["module"] = scope.attr("__name__");
+#if PY_MAJOR_VERSION >= 3 && PY_MINOR_VERSION >= 3
+            if (hasattr(scope, "__qualname__"))
+                kwargs["qualname"] = scope.attr("__qualname__").cast<std::string>() + "." + name;
+#endif
         }
         update();
     }

tests/test_enum.cpp

@@ -54,6 +54,8 @@ enum class Py3EnumNonUnique {
     X = 1
 };
 
+class DummyScope {};
+
 std::string test_scoped_enum(ScopedEnum z) {
     return "ScopedEnum::" + std::string(z == ScopedEnum::Two ? "Two" : "Three");
 }
@@ -77,7 +79,8 @@ test_initializer enums([](py::module &m) {
         .export_values();
 
 #if PY_VERSION_HEX >= 0x03000000
-    py::py3_enum<Py3EnumEmpty>(m, "Py3EnumEmpty");
+    auto scope = py::class_<DummyScope>(m, "DummyScope");
+    py::py3_enum<Py3EnumEmpty>(scope, "Py3EnumEmpty");
 
     py::py3_enum<Py3Enum>(m, "Py3Enum")
         .value("A", Py3Enum::A)

tests/test_enum.py

@@ -120,10 +120,12 @@ def test_binary_operators():
 @pytest.requires_py3
 def test_py3_enum():
     from pybind11_tests import (
-        Py3Enum, Py3EnumEmpty, Py3EnumScoped,
+        Py3Enum, DummyScope, Py3EnumScoped,
         make_py3_enum, take_py3_enum, non_unique_py3_enum
     )
 
+    Py3EnumEmpty = DummyScope.Py3EnumEmpty
+
     from enum import IntEnum
 
     expected = {
@@ -137,6 +139,10 @@ def test_py3_enum():
         assert sorted(tp.__members__.items()) == entries
         assert tp.__module__ == 'pybind11_tests'
 
+    assert Py3Enum.__qualname__ == 'Py3Enum'
+    assert Py3EnumEmpty.__qualname__ == 'DummyScope.Py3EnumEmpty'
+    assert Py3EnumScoped.__qualname__ == 'Py3EnumScoped'
+
     assert make_py3_enum(True) is Py3EnumScoped.X
     assert make_py3_enum(False) is Py3EnumScoped.Y