shiboken: Fix Qt properties not working in classes inheriting QObject

The fixes for PYSIDE-803 caused setattro methods to be generated
for many classes, resulting in QObject's setattro method no longer
being called.

Generate property code in each class inheriting QObject.

Task-number: PYSIDE-803
Fixes: PYSIDE-1255
Change-Id: I56f52fb43c4ddc77914090ac122776050354ddbe
Reviewed-by: Christian Tismer <tismer@stackless.com>

3 files changed, 140 insertions, 0 deletions

diff --git a/sources/pyside2/tests/pysidetest/CMakeLists.txt b/sources/pyside2/tests/pysidetest/CMakeLists.txt
index 3ba2ad29d..46a8023c3 100644
--- a/sources/pyside2/tests/pysidetest/CMakeLists.txt
+++ b/sources/pyside2/tests/pysidetest/CMakeLists.txt
@@ -143,6 +143,7 @@ PYSIDE_TEST(mixin_signal_slots_test.py)
 PYSIDE_TEST(modelview_test.py)
 PYSIDE_TEST(new_inherited_functions_test.py)
 PYSIDE_TEST(notify_id.py)
+PYSIDE_TEST(properties_test.py)
 PYSIDE_TEST(qapp_like_a_macro_test.py)
 PYSIDE_TEST(qvariant_test.py)
 PYSIDE_TEST(repr_test.py)
diff --git a/sources/pyside2/tests/pysidetest/properties_test.py b/sources/pyside2/tests/pysidetest/properties_test.py
new file mode 100644
index 000000000..cedfac8d1
--- /dev/null
+++ b/sources/pyside2/tests/pysidetest/properties_test.py
@@ -0,0 +1,132 @@
+#############################################################################
+##
+## Copyright (C) 2020 The Qt Company Ltd.
+## Contact: https://www.qt.io/licensing/
+##
+## This file is part of the test suite of Qt for Python.
+##
+## $QT_BEGIN_LICENSE:GPL-EXCEPT$
+## Commercial License Usage
+## Licensees holding valid commercial Qt licenses may use this file in
+## accordance with the commercial license agreement provided with the
+## Software or, alternatively, in accordance with the terms contained in
+## a written agreement between you and The Qt Company. For licensing terms
+## and conditions see https://www.qt.io/terms-conditions. For further
+## information use the contact form at https://www.qt.io/contact-us.
+##
+## GNU General Public License Usage
+## Alternatively, this file may be used under the terms of the GNU
+## General Public License version 3 as published by the Free Software
+## Foundation with exceptions as appearing in the file LICENSE.GPL3-EXCEPT
+## included in the packaging of this file. Please review the following
+## information to ensure the GNU General Public License requirements will
+## be met: https://www.gnu.org/licenses/gpl-3.0.html.
+##
+## $QT_END_LICENSE$
+##
+#############################################################################
+
+import os
+import sys
+import unittest
+
+sys.path.append(os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
+from init_paths import init_test_paths
+init_test_paths(False)
+
+from PySide2.QtCore import QObject, QStringListModel, Signal, Property, Slot
+
+"""Tests PySide2.QtCore.Property()"""
+
+
+class TestObject(QObject):
+
+    valueChanged = Signal()
+
+    def __init__(self, parent=None):
+        super(TestObject, self).__init__(parent)
+        self._value = -1
+        self.valueChanged.connect(self._changed)
+        self.getter_called = 0
+        self.setter_called = 0
+        self.changed_emitted = 0
+
+    @Slot(int)
+    def _changed(self):
+        self.changed_emitted += 1
+
+    def getValue(self):
+        self.getter_called += 1
+        return self._value
+
+    def setValue(self, value):
+        self.setter_called += 1
+        if (self._value != value):
+            self._value = value
+            self.valueChanged.emit()
+
+    value = Property(int, fget=getValue, fset=setValue,
+                     notify=valueChanged)
+
+
+class TestDerivedObject(QStringListModel):
+
+    valueChanged = Signal()
+
+    def __init__(self, parent=None):
+        super(TestDerivedObject, self).__init__(parent)
+        self._value = -1
+        self.valueChanged.connect(self._changed)
+        self.getter_called = 0
+        self.setter_called = 0
+        self.changed_emitted = 0
+
+    @Slot(int)
+    def _changed(self):
+        self.changed_emitted += 1
+
+    def getValue(self):
+        self.getter_called += 1
+        return self._value
+
+    def setValue(self, value):
+        self.setter_called += 1
+        if (self._value != value):
+            self._value = value
+            self.valueChanged.emit()
+
+    value = Property(int, fget=getValue, fset=setValue,
+                     notify=valueChanged)
+
+
+class PropertyTest(unittest.TestCase):
+
+    def test1Object(self):
+        """Basic property test."""
+        testObject = TestObject()
+        v = testObject.value
+        self.assertEqual(v, -1)
+        self.assertEqual(testObject.getter_called, 1)
+        testObject.value = 42
+        v = testObject.value
+        self.assertEqual(v, 42)
+        self.assertEqual(testObject.changed_emitted, 1)
+        self.assertEqual(testObject.setter_called, 1)
+        self.assertEqual(testObject.getter_called, 2)
+
+    def test2DerivedObject(self):
+        """PYSIDE-1255: Run the same test for a class inheriting QObject."""
+        testObject = TestDerivedObject()
+        v = testObject.value
+        self.assertEqual(v, -1)
+        self.assertEqual(testObject.getter_called, 1)
+        testObject.value = 42
+        v = testObject.value
+        self.assertEqual(v, 42)
+        self.assertEqual(testObject.changed_emitted, 1)
+        self.assertEqual(testObject.setter_called, 1)
+        self.assertEqual(testObject.getter_called, 2)
+
+
+if __name__ == '__main__':
+    unittest.main()
diff --git a/sources/shiboken2/generator/shiboken2/shibokengenerator.cpp b/sources/shiboken2/generator/shiboken2/shibokengenerator.cpp
index fbd3c314b..a712c3ebb 100644
--- a/sources/shiboken2/generator/shiboken2/shibokengenerator.cpp
+++ b/sources/shiboken2/generator/shiboken2/shibokengenerator.cpp
@@ -2219,6 +2219,13 @@ ShibokenGenerator::AttroCheck ShibokenGenerator::checkAttroFunctionNeeds(const A
             result |= AttroCheckFlag::SetattroQObject;
         if (useOverrideCaching(metaClass))
             result |= AttroCheckFlag::SetattroMethodOverride;
+        // PYSIDE-1255: If setattro is generated for a class inheriting
+        // QObject, the property code needs to be generated, too.
+        if ((result & AttroCheckFlag::SetattroMask) != 0
+            && !result.testFlag(AttroCheckFlag::SetattroQObject)
+            && metaClass->isQObject()) {
+            result |= AttroCheckFlag::SetattroQObject;
+        }
     }
     return result;
 }