feature: fix the UIC switching problem

The BindingManager::getOverride function computes the current
switch state from information of a type object. But the type object
must first be updated in case a switch has happened.

The solution was an extra update call at the beginning of the
function.

This solution _always_ works, with or without inheritance, for
Python >= 3.7.

[ChangeLog][shiboken6] Coexistence of different feature
selections works now, especially for UIC files and inheritance.

Fixes: PYSIDE-1626
Change-Id: I577331cfb2d7511110d1e16e729bed80985340a0
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@qt.io>
(cherry picked from commit 9b5fa60d1fed5025e97c393ba1bab80f81ba833a)
Reviewed-by: Cristian Maureira-Fredes <cristian.maureira-fredes@qt.io>
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>

9 files changed, 283 insertions, 3 deletions

diff --git a/sources/pyside2/libpyside/feature_select.cpp b/sources/pyside2/libpyside/feature_select.cpp
index 1e1eb9357..dd8a11ee4 100644
--- a/sources/pyside2/libpyside/feature_select.cpp
+++ b/sources/pyside2/libpyside/feature_select.cpp
@@ -237,6 +237,7 @@ static bool replaceClassDict(PyTypeObject *type)
     // Replace `__dict__` which usually has refcount 1 (but see cyclic_test.py)
     Py_DECREF(type->tp_dict);
     type->tp_dict = new_dict;
+    setCurrentSelectId(type, select_id.object());
     return true;
 }
 
@@ -257,6 +258,7 @@ static bool addNewDict(PyTypeObject *type, PyObject *select_id)
     setNextDict(dict, new_dict);
     setNextDict(new_dict, next_dict);
     type->tp_dict = new_dict;
+    setCurrentSelectId(type, select_id);
     return true;
 }
 
@@ -279,6 +281,7 @@ static bool moveToFeatureSet(PyTypeObject *type, PyObject *select_id)
         }
     } while (dict != initial_dict);
     type->tp_dict = initial_dict;
+    setCurrentSelectId(type, getSelectId(initial_dict));
     return false;
 }
 
@@ -400,6 +403,13 @@ void Select(PyObject *obj)
     type->tp_dict = SelectFeatureSet(type);
 }
 
+PyObject *Select(PyTypeObject *type)
+{
+    if (featurePointer != nullptr)
+        type->tp_dict = SelectFeatureSet(type);
+    return type->tp_dict;
+}
+
 static bool feature_01_addLowerNames(PyTypeObject *type, PyObject *prev_dict, int id);
 static bool feature_02_true_property(PyTypeObject *type, PyObject *prev_dict, int id);
 static bool feature_04_addDummyNames(PyTypeObject *type, PyObject *prev_dict, int id);
@@ -428,11 +438,11 @@ void finalize()
 }
 
 static bool patch_property_impl();
+static bool is_initialized = false;
 
 void init()
 {
     // This function can be called multiple times.
-    static bool is_initialized = false;
     if (!is_initialized) {
         fast_id_array = &_fast_id_array[1];
         for (int idx = -1; idx < 256; ++idx)
@@ -448,6 +458,14 @@ void init()
     cached_globals = nullptr;
 }
 
+void Enable(bool enable)
+{
+    if (!is_initialized)
+        return;
+    featurePointer = enable ? featureProcArray : nullptr;
+    initSelectableFeature(enable ? SelectFeatureSet : nullptr);
+}
+
 //////////////////////////////////////////////////////////////////////////////
 //
 // PYSIDE-1019: Support switchable extensions
diff --git a/sources/pyside2/tests/QtCore/CMakeLists.txt b/sources/pyside2/tests/QtCore/CMakeLists.txt
index 9d268e079..c7e50d640 100644
--- a/sources/pyside2/tests/QtCore/CMakeLists.txt
+++ b/sources/pyside2/tests/QtCore/CMakeLists.txt
@@ -37,6 +37,7 @@ PYSIDE_TEST(deletelater_test.py)
 PYSIDE_TEST(destroysignal_test.py)
 PYSIDE_TEST(duck_punching_test.py)
 PYSIDE_TEST(emoji_string_test.py)
+PYSIDE_TEST(feature_with_uic_test.py)
 PYSIDE_TEST(hash_test.py)
 PYSIDE_TEST(inherits_test.py)
 PYSIDE_TEST(max_signals.py)
diff --git a/sources/pyside2/tests/QtCore/feature_with_uic/__init__.py b/sources/pyside2/tests/QtCore/feature_with_uic/__init__.py
new file mode 100644
index 000000000..396f82fb1
--- /dev/null
+++ b/sources/pyside2/tests/QtCore/feature_with_uic/__init__.py
@@ -0,0 +1,29 @@
+#############################################################################
+##
+## 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.
+##
+## $QT_END_LICENSE$
+##
+#############################################################################
+
+# this file intentionally left blank
diff --git a/sources/pyside2/tests/QtCore/feature_with_uic/window.py b/sources/pyside2/tests/QtCore/feature_with_uic/window.py
new file mode 100644
index 000000000..db0fbd033
--- /dev/null
+++ b/sources/pyside2/tests/QtCore/feature_with_uic/window.py
@@ -0,0 +1,81 @@
+# -*- coding: utf-8 -*-
+#############################################################################
+##
+## Copyright (C) 2021 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.
+##
+## $QT_END_LICENSE$
+##
+#############################################################################
+
+################################################################################
+## Form generated from reading UI file 'window.ui'
+##
+## Created by: Qt User Interface Compiler version 5.15.2
+##
+## WARNING! All changes made in this file will be lost when recompiling UI file!
+################################################################################
+
+from PySide2.QtCore import *
+from PySide2.QtGui import *
+from PySide2.QtWidgets import *
+
+
+class Ui_MainWindow(object):
+    def setupUi(self, MainWindow):
+        if not MainWindow.objectName():
+            MainWindow.setObjectName(u"MainWindow")
+        MainWindow.resize(263, 196)
+        self.centralwidget = QWidget(MainWindow)
+        self.centralwidget.setObjectName(u"centralwidget")
+        self.horizontalLayout = QHBoxLayout(self.centralwidget)
+        self.horizontalLayout.setObjectName(u"horizontalLayout")
+        self.verticalLayout = QVBoxLayout()
+        self.verticalLayout.setObjectName(u"verticalLayout")
+        self.pushButton = QPushButton(self.centralwidget)
+        self.pushButton.setObjectName(u"pushButton")
+
+        self.verticalLayout.addWidget(self.pushButton)
+
+
+        self.horizontalLayout.addLayout(self.verticalLayout)
+
+        MainWindow.setCentralWidget(self.centralwidget)
+        self.menubar = QMenuBar(MainWindow)
+        self.menubar.setObjectName(u"menubar")
+        self.menubar.setGeometry(QRect(0, 0, 263, 23))
+        MainWindow.setMenuBar(self.menubar)
+        self.statusbar = QStatusBar(MainWindow)
+        self.statusbar.setObjectName(u"statusbar")
+        MainWindow.setStatusBar(self.statusbar)
+
+        self.retranslateUi(MainWindow)
+        self.pushButton.clicked.connect(MainWindow.close)
+
+        QMetaObject.connectSlotsByName(MainWindow)
+    # setupUi
+
+    def retranslateUi(self, MainWindow):
+        MainWindow.setWindowTitle(QCoreApplication.translate("MainWindow", u"MainWindow", None))
+        self.pushButton.setText(QCoreApplication.translate("MainWindow", u"PushButton", None))
+    # retranslateUi
+
diff --git a/sources/pyside2/tests/QtCore/feature_with_uic/window.ui b/sources/pyside2/tests/QtCore/feature_with_uic/window.ui
new file mode 100644
index 000000000..0b85824ea
--- /dev/null
+++ b/sources/pyside2/tests/QtCore/feature_with_uic/window.ui
@@ -0,0 +1,62 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<ui version="4.0">
+ <class>MainWindow</class>
+ <widget class="QMainWindow" name="MainWindow">
+  <property name="geometry">
+   <rect>
+    <x>0</x>
+    <y>0</y>
+    <width>263</width>
+    <height>196</height>
+   </rect>
+  </property>
+  <property name="windowTitle">
+   <string>MainWindow</string>
+  </property>
+  <widget class="QWidget" name="centralwidget">
+   <layout class="QHBoxLayout" name="horizontalLayout">
+    <item>
+     <layout class="QVBoxLayout" name="verticalLayout">
+      <item>
+       <widget class="QPushButton" name="pushButton">
+        <property name="text">
+         <string>PushButton</string>
+        </property>
+       </widget>
+      </item>
+     </layout>
+    </item>
+   </layout>
+  </widget>
+  <widget class="QMenuBar" name="menubar">
+   <property name="geometry">
+    <rect>
+     <x>0</x>
+     <y>0</y>
+     <width>263</width>
+     <height>23</height>
+    </rect>
+   </property>
+  </widget>
+  <widget class="QStatusBar" name="statusbar"/>
+ </widget>
+ <resources/>
+ <connections>
+  <connection>
+   <sender>pushButton</sender>
+   <signal>clicked()</signal>
+   <receiver>MainWindow</receiver>
+   <slot>close()</slot>
+   <hints>
+    <hint type="sourcelabel">
+     <x>131</x>
+     <y>97</y>
+    </hint>
+    <hint type="destinationlabel">
+     <x>131</x>
+     <y>97</y>
+    </hint>
+   </hints>
+  </connection>
+ </connections>
+</ui>
diff --git a/sources/pyside2/tests/QtCore/feature_with_uic_test.py b/sources/pyside2/tests/QtCore/feature_with_uic_test.py
new file mode 100644
index 000000000..5b61a4afb
--- /dev/null
+++ b/sources/pyside2/tests/QtCore/feature_with_uic_test.py
@@ -0,0 +1,76 @@
+#############################################################################
+##
+## Copyright (C) 2021 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.
+##
+## $QT_END_LICENSE$
+##
+#############################################################################
+
+"""
+feature_with_uic_test.py
+------------------------
+
+Check if feature switching works with a normal UIC file.
+This crashed due to callbacks into QApplication.
+
+PYSIDE-1626: Switch early in `BindingManager::getOverride`.
+"""
+
+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 helper.usesqapplication import UsesQApplication
+
+from PySide2.QtCore import QLibraryInfo, qVersion
+from PySide2.QtWidgets import QApplication, QMainWindow
+
+if sys.version_info[0] >= 3:
+    from __feature__ import snake_case
+
+from feature_with_uic.window import Ui_MainWindow
+
+
+class MainWindow(QMainWindow, Ui_MainWindow):
+
+    def __init__(self):
+        super().__init__()
+        self.setupUi(self)
+
+
+class FeatureTest(UsesQApplication):
+
+    def testFeaturesWorkWithUIC(self):
+        window = MainWindow()
+        window.set_window_title(qVersion())
+        window.show()
+        while not window.window_handle().is_exposed():
+            QCoreApplication.process_events()
+
+
+if __name__ == '__main__' and sys.version_info[0] >= 3:
+    unittest.main()
diff --git a/sources/shiboken2/libshiboken/basewrapper.cpp b/sources/shiboken2/libshiboken/basewrapper.cpp
index 48be4ea04..ab637354e 100644
--- a/sources/shiboken2/libshiboken/basewrapper.cpp
+++ b/sources/shiboken2/libshiboken/basewrapper.cpp
@@ -659,6 +659,13 @@ void SbkObjectType_SetPropertyStrings(PyTypeObject *type, const char **strings)
     PepType_SOTP(reinterpret_cast<SbkObjectType *>(type))->propertyStrings = strings;
 }
 
+// PYSIDE-1626: Enforcing a context switch without further action.
+void SbkObjectType_UpdateFeature(PyTypeObject *type)
+{
+    if (SelectFeatureSet != nullptr)
+        type->tp_dict = SelectFeatureSet(type);
+}
+
 //
 //////////////////////////////////////////////////////////////////////////////
 
diff --git a/sources/shiboken2/libshiboken/basewrapper.h b/sources/shiboken2/libshiboken/basewrapper.h
index 322581353..c6fc1af2a 100644
--- a/sources/shiboken2/libshiboken/basewrapper.h
+++ b/sources/shiboken2/libshiboken/basewrapper.h
@@ -80,11 +80,14 @@ typedef void (*SubTypeInitHook)(SbkObjectType *, PyObject *, PyObject *);
 typedef PyObject *(*SelectableFeatureHook)(PyTypeObject *);
 LIBSHIBOKEN_API SelectableFeatureHook initSelectableFeature(SelectableFeatureHook func);
 
-// PYSIDE-1019: Get access to PySide reserved bits.
+/// PYSIDE-1019: Get access to PySide reserved bits.
 LIBSHIBOKEN_API int SbkObjectType_GetReserved(PyTypeObject *type);
 LIBSHIBOKEN_API void SbkObjectType_SetReserved(PyTypeObject *type, int value);
 
-// PYSIDE-1019: Get access to PySide property strings.
+/// PYSIDE-1626: Enforcing a context switch without further action.
+LIBSHIBOKEN_API void SbkObjectType_UpdateFeature(PyTypeObject *type);
+
+/// PYSIDE-1019: Get access to PySide property strings.
 LIBSHIBOKEN_API const char **SbkObjectType_GetPropertyStrings(PyTypeObject *type);
 LIBSHIBOKEN_API void SbkObjectType_SetPropertyStrings(PyTypeObject *type, const char **strings);
 
diff --git a/sources/shiboken2/libshiboken/bindingmanager.cpp b/sources/shiboken2/libshiboken/bindingmanager.cpp
index 6c1300188..7111197bf 100644
--- a/sources/shiboken2/libshiboken/bindingmanager.cpp
+++ b/sources/shiboken2/libshiboken/bindingmanager.cpp
@@ -274,6 +274,9 @@ PyObject *BindingManager::getOverride(const void *cptr,
     if (!wrapper || reinterpret_cast<const PyObject *>(wrapper)->ob_refcnt == 0)
         return nullptr;
 
+    // PYSIDE-1626: Touch the type to initiate switching early.
+    SbkObjectType_UpdateFeature(Py_TYPE(wrapper));
+
     int flag = currentSelectId(Py_TYPE(wrapper));
     int propFlag = isdigit(methodName[0]) ? methodName[0] - '0' : 0;
     if ((flag & 0x02) != 0 && (propFlag & 3) != 0) {