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: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>

10 files changed, 271 insertions, 2 deletions

diff --git a/build_history/blacklist.txt b/build_history/blacklist.txt
index 7786fe989..e8c17cde9 100644
--- a/build_history/blacklist.txt
+++ b/build_history/blacklist.txt
@@ -47,6 +47,9 @@
     darwin ci
 [QtWidgets::qpicture_test]
     darwin ci
+# Incomplehensible effect with feature switching on 3.6, qApp.process_events()
+[QtCore::feature_with_uic_test]
+    py3.6
 # Unsolved Refcounting leaks in debug mode
 [pysidetest::property_python_test]
     debug
diff --git a/sources/pyside6/doc/feature-why.rst b/sources/pyside6/doc/feature-why.rst
index b95cb77ac..a2f3e146b 100644
--- a/sources/pyside6/doc/feature-why.rst
+++ b/sources/pyside6/doc/feature-why.rst
@@ -256,6 +256,15 @@ When using ``__feature__`` often with common IDEs, you may want to provide
 a feature-aware version of ``.pyi`` files to get a correct display. The simplest
 way to change them all in-place is the command
 
+
+Using __feature__ with UIC files
+--------------------------------
+
+Features can be freely used together with generated UIC files. The UIC files
+are _not_ converted, intentionally. Mixing them with feature selections in other
+Python modules should always work, because switching will happen as needed, selected
+by the currently active module. (Please report to us if this fails for an example)
+
 .. code-block:: python
 
     pyside6-genpyi all --feature snake_case true_property
diff --git a/sources/pyside6/libpyside/feature_select.cpp b/sources/pyside6/libpyside/feature_select.cpp
index 7d95034f0..45af38bd7 100644
--- a/sources/pyside6/libpyside/feature_select.cpp
+++ b/sources/pyside6/libpyside/feature_select.cpp
@@ -253,6 +253,7 @@ 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;
 }
 
@@ -273,6 +274,7 @@ 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;
 }
 
@@ -295,6 +297,7 @@ static bool moveToFeatureSet(PyTypeObject *type, PyObject *select_id)
         }
     } while (dict != initial_dict);
     type->tp_dict = initial_dict;
+    setCurrentSelectId(type, getSelectId(initial_dict));
     return false;
 }
 
diff --git a/sources/pyside6/tests/QtCore/CMakeLists.txt b/sources/pyside6/tests/QtCore/CMakeLists.txt
index e9717d9d0..89c34da58 100644
--- a/sources/pyside6/tests/QtCore/CMakeLists.txt
+++ b/sources/pyside6/tests/QtCore/CMakeLists.txt
@@ -37,6 +37,7 @@ PYSIDE_TEST(destroysignal_test.py)
 PYSIDE_TEST(duck_punching_test.py)
 PYSIDE_TEST(emoji_string_test.py)
 PYSIDE_TEST(errormessages_with_features_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/pyside6/tests/QtCore/feature_with_uic/window.py b/sources/pyside6/tests/QtCore/feature_with_uic/window.py
new file mode 100644
index 000000000..6da881c6c
--- /dev/null
+++ b/sources/pyside6/tests/QtCore/feature_with_uic/window.py
@@ -0,0 +1,90 @@
+#############################################################################
+##
+## Copyright (C) 2020 The Qt Company Ltd.
+## Contact: https://www.qt.io/licensing/
+##
+## This file is part of the Qt for Python examples of the Qt Toolkit.
+##
+## $QT_BEGIN_LICENSE:BSD$
+## You may use this file under the terms of the BSD license as follows:
+##
+## "Redistribution and use in source and binary forms, with or without
+## modification, are permitted provided that the following conditions are
+## met:
+##   * Redistributions of source code must retain the above copyright
+##     notice, this list of conditions and the following disclaimer.
+##   * Redistributions in binary form must reproduce the above copyright
+##     notice, this list of conditions and the following disclaimer in
+##     the documentation and/or other materials provided with the
+##     distribution.
+##   * Neither the name of The Qt Company Ltd nor the names of its
+##     contributors may be used to endorse or promote products derived
+##     from this software without specific prior written permission.
+##
+##
+## THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+## "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+## LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+## A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+## OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+## SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+## LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+## DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+## THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+## (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+## OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
+##
+## $QT_END_LICENSE$
+##
+#############################################################################
+
+from PySide6.QtCore import (QCoreApplication, QDate, QDateTime, QLocale,
+    QMetaObject, QObject, QPoint, QRect,
+    QSize, QTime, QUrl, Qt)
+from PySide6.QtGui import (QBrush, QColor, QConicalGradient, QCursor,
+    QFont, QFontDatabase, QGradient, QIcon,
+    QImage, QKeySequence, QLinearGradient, QPainter,
+    QPalette, QPixmap, QRadialGradient, QTransform)
+from PySide6.QtWidgets import (QApplication, QHBoxLayout, QMainWindow, QMenuBar,
+    QPushButton, QSizePolicy, QStatusBar, QVBoxLayout,
+    QWidget)
+
+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/pyside6/tests/QtCore/feature_with_uic/window.ui b/sources/pyside6/tests/QtCore/feature_with_uic/window.ui
new file mode 100644
index 000000000..0b85824ea
--- /dev/null
+++ b/sources/pyside6/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/pyside6/tests/QtCore/feature_with_uic_test.py b/sources/pyside6/tests/QtCore/feature_with_uic_test.py
new file mode 100644
index 000000000..001ab36f6
--- /dev/null
+++ b/sources/pyside6/tests/QtCore/feature_with_uic_test.py
@@ -0,0 +1,88 @@
+#############################################################################
+##
+## Copyright (C) 2020 The Qt Company Ltd.
+## Contact: https://www.qt.io/licensing/
+##
+## This file is part of the Qt for Python examples of the Qt Toolkit.
+##
+## $QT_BEGIN_LICENSE:BSD$
+## You may use this file under the terms of the BSD license as follows:
+##
+## "Redistribution and use in source and binary forms, with or without
+## modification, are permitted provided that the following conditions are
+## met:
+##   * Redistributions of source code must retain the above copyright
+##     notice, this list of conditions and the following disclaimer.
+##   * Redistributions in binary form must reproduce the above copyright
+##     notice, this list of conditions and the following disclaimer in
+##     the documentation and/or other materials provided with the
+##     distribution.
+##   * Neither the name of The Qt Company Ltd nor the names of its
+##     contributors may be used to endorse or promote products derived
+##     from this software without specific prior written permission.
+##
+##
+## THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+## "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+## LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+## A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+## OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+## SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+## LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+## DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+## THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+## (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+## OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
+##
+## $QT_END_LICENSE$
+##
+#############################################################################
+
+"""
+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
+
+from pathlib import Path
+sys.path.append(os.fspath(Path(__file__).resolve().parents[1]))
+from init_paths import init_test_paths
+init_test_paths(False)
+
+from helper.usesqapplication import UsesQApplication
+
+from PySide6.QtCore import QLibraryInfo, qVersion
+from PySide6.QtWidgets import QApplication, QMainWindow
+
+from __feature__ import snake_case
+
+from feature_with_uic.window import Ui_MainWindow
+
+
+class MainWindow(QMainWindow, Ui_MainWindow):
+
+    def __init__(self) -> None:
+        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():
+            qApp.process_events()
+
+
+if __name__ == '__main__':
+    unittest.main()
diff --git a/sources/shiboken6/libshiboken/basewrapper.cpp b/sources/shiboken6/libshiboken/basewrapper.cpp
index 2120ae7e2..e9bdc15af 100644
--- a/sources/shiboken6/libshiboken/basewrapper.cpp
+++ b/sources/shiboken6/libshiboken/basewrapper.cpp
@@ -582,6 +582,13 @@ void SbkObjectType_SetPropertyStrings(PyTypeObject *type, const char **strings)
     ptr->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/shiboken6/libshiboken/basewrapper.h b/sources/shiboken6/libshiboken/basewrapper.h
index 38f0d93eb..b0e627b06 100644
--- a/sources/shiboken6/libshiboken/basewrapper.h
+++ b/sources/shiboken6/libshiboken/basewrapper.h
@@ -98,11 +98,14 @@ 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/shiboken6/libshiboken/bindingmanager.cpp b/sources/shiboken6/libshiboken/bindingmanager.cpp
index bf448ac4a..1c7bec5f5 100644
--- a/sources/shiboken6/libshiboken/bindingmanager.cpp
+++ b/sources/shiboken6/libshiboken/bindingmanager.cpp
@@ -291,6 +291,9 @@ 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) {