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 <[email protected]>

Author: FriedemannKleint

build_history/blacklist.txt

@@ -37,10 +37,6 @@
 # Open GL functions failures on macOS (2/2020)
 [QtQml::qqmlnetwork_test]
     linux ci    # extended, see PyPy section below
-[QtWidgets::bug_750]
-    darwin ci
-[QtWidgets::qpicture_test]
-    darwin ci
 [QtAsyncio::qasyncio_test_chain]
     win32
 [QtQml::bug_825]

sources/pyside6/tests/QtWidgets/bug_750.py

@@ -13,24 +13,28 @@
 
 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)
 

sources/pyside6/tests/QtWidgets/qpicture_test.py

@@ -12,16 +12,20 @@
 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 @@ def testFromData(self):
 
         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()