tests: Fix warning about QBackingStore::flush() being called without handle

Call qApp->quit() delayed from the paint event. This fixes crashes on
macOS and warnings:

 QBackingStore::flush() called for  QWidgetWindow(0x600003a22460, name="MyWidgetClassWindow")  which does not have a handle.

Pick-to: 6.8
Change-Id: I2e5d8aa1cfc36c4c247f681b4219f52c1a618737
Reviewed-by: Cristian Maureira-Fredes <cristian.maureira-fredes@qt.io>

2 files changed, 21 insertions, 13 deletions

diff --git a/sources/pyside6/tests/QtWidgets/bug_750.py b/sources/pyside6/tests/QtWidgets/bug_750.py
index 074f569f6..61356c173 100644
--- a/sources/pyside6/tests/QtWidgets/bug_750.py
+++ b/sources/pyside6/tests/QtWidgets/bug_750.py
@@ -13,24 +13,28 @@ init_test_paths(False)
 
 from helper.usesqapplication import UsesQApplication
 
-from PySide6.QtCore import QTimer
+from PySide6.QtCore import QCoreApplication, QTimer
 from PySide6.QtGui import QPainter
 from PySide6.QtWidgets import QWidget
 
 
 class MyWidget(QWidget):
+    def __init__(self):
+        super().__init__()
+        self._info = None
+
     def paintEvent(self, e):
-        p = QPainter(self)
-        self._info = p.fontInfo()
-        self._app.quit()
+        with QPainter(self) as p:
+            self._info = p.fontInfo()
+        QTimer.singleShot(0, qApp.quit)  # noqa: F821
 
 
 class TestQPainter(UsesQApplication):
     def testFontInfo(self):
         w = MyWidget()
-        w._app = self.app
-        w._info = None
-        QTimer.singleShot(300, w.show)
+        w.show()
+        while not w.windowHandle().isExposed():
+            QCoreApplication.processEvents()
         self.app.exec()
         self.assertTrue(w._info)
 
diff --git a/sources/pyside6/tests/QtWidgets/qpicture_test.py b/sources/pyside6/tests/QtWidgets/qpicture_test.py
index 884f391a9..e9b0440c2 100644
--- a/sources/pyside6/tests/QtWidgets/qpicture_test.py
+++ b/sources/pyside6/tests/QtWidgets/qpicture_test.py
@@ -12,16 +12,20 @@ from init_paths import init_test_paths
 init_test_paths(False)
 
 from helper.usesqapplication import UsesQApplication
-from PySide6.QtCore import QTimer
+from PySide6.QtCore import QCoreApplication, QTimer
 from PySide6.QtGui import QPicture, QPainter
 from PySide6.QtWidgets import QWidget
 
 
 class MyWidget(QWidget):
+    def __init__(self, picture):
+        super().__init__()
+        self._picture = picture
+
     def paintEvent(self, e):
         with QPainter(self) as p:
             p.drawPicture(0, 0, self._picture)
-        self._app.quit()
+        QTimer.singleShot(0, qApp.quit)  # noqa: F821
 
 
 class QPictureTest(UsesQApplication):
@@ -36,11 +40,11 @@ class QPictureTest(UsesQApplication):
 
         self.assertEqual(picture2.data(), picture.data())
 
-        w = MyWidget()
-        w._picture = picture2
-        w._app = self.app
+        w = MyWidget(picture2)
 
-        QTimer.singleShot(300, w.show)
+        w.show()
+        while not w.windowHandle().isExposed():
+            QCoreApplication.processEvents()
         self.app.exec()