Fix crash when accessing QStyleHints before QGuiApplication is constructed.

Make styleHints a static member variable of QGuiApplicationPrivate and
fix accessor accordingly. Extend tst_QApplication::settableStyleHints()
to run without QApplication instance as well and add a similar test
to  QGuiApplication.

Task-number: QTBUG-44499
Change-Id: I42b92ef38f7dd512d08d70accfa7dd4f09a22f01
Reviewed-by: Shawn Rutledge <shawn.rutledge@digia.com>

4 files changed, 8 insertions, 8 deletions

diff --git a/src/widgets/kernel/qapplication.cpp b/src/widgets/kernel/qapplication.cpp
index ad51dc5055..e761520228 100644
--- a/src/widgets/kernel/qapplication.cpp
+++ b/src/widgets/kernel/qapplication.cpp
@@ -2892,7 +2892,7 @@ void QApplication::setStartDragTime(int ms)
 
 int QApplication::startDragTime()
 {
-    return qApp->styleHints()->startDragTime();
+    return QGuiApplication::styleHints()->startDragTime();
 }
 
 /*
@@ -2930,7 +2930,7 @@ void QApplication::setStartDragDistance(int l)
 
 int QApplication::startDragDistance()
 {
-    return qApp->styleHints()->startDragDistance();
+    return QGuiApplication::styleHints()->startDragDistance();
 }
 
 /*!
@@ -3973,7 +3973,7 @@ void QApplication::setCursorFlashTime(int msecs)
 
 int QApplication::cursorFlashTime()
 {
-    return qApp->styleHints()->cursorFlashTime();
+    return QGuiApplication::styleHints()->cursorFlashTime();
 }
 
 /*!
@@ -3991,7 +3991,7 @@ void QApplication::setDoubleClickInterval(int ms)
 
 int QApplication::doubleClickInterval()
 {
-    return qApp->styleHints()->mouseDoubleClickInterval();
+    return QGuiApplication::styleHints()->mouseDoubleClickInterval();
 }
 
 /*!
@@ -4019,7 +4019,7 @@ void QApplication::setKeyboardInputInterval(int ms)
 
 int QApplication::keyboardInputInterval()
 {
-    return qApp->styleHints()->keyboardInputInterval();
+    return QGuiApplication::styleHints()->keyboardInputInterval();
 }
 
 /*!
diff --git a/src/widgets/widgets/qabstractspinbox.cpp b/src/widgets/widgets/qabstractspinbox.cpp
index eea63e5864..2f833499d9 100644
--- a/src/widgets/widgets/qabstractspinbox.cpp
+++ b/src/widgets/widgets/qabstractspinbox.cpp
@@ -1181,7 +1181,7 @@ void QAbstractSpinBox::timerEvent(QTimerEvent *event)
         killTimer(d->spinClickThresholdTimerId);
         d->spinClickThresholdTimerId = -1;
         d->effectiveSpinRepeatRate = d->buttonState & Keyboard
-                                     ? qApp->styleHints()->keyboardAutoRepeatRate()
+                                     ? QGuiApplication::styleHints()->keyboardAutoRepeatRate()
                                      : d->spinClickTimerInterval;
         d->spinClickTimerId = startTimer(d->effectiveSpinRepeatRate);
         doStep = true;
diff --git a/src/widgets/widgets/qlineedit.cpp b/src/widgets/widgets/qlineedit.cpp
index f115ce3079..0500907b3d 100644
--- a/src/widgets/widgets/qlineedit.cpp
+++ b/src/widgets/widgets/qlineedit.cpp
@@ -2153,7 +2153,7 @@ QMenu *QLineEdit::createStandardContextMenu()
     d->selectAllAction = action;
     connect(action, SIGNAL(triggered()), SLOT(selectAll()));
 
-    if (!d->control->isReadOnly() && qApp->styleHints()->useRtlExtensions()) {
+    if (!d->control->isReadOnly() && QGuiApplication::styleHints()->useRtlExtensions()) {
         popup->addSeparator();
         QUnicodeControlCharacterMenu *ctrlCharacterMenu = new QUnicodeControlCharacterMenu(this, popup);
         popup->addMenu(ctrlCharacterMenu);
diff --git a/src/widgets/widgets/qwidgettextcontrol.cpp b/src/widgets/widgets/qwidgettextcontrol.cpp
index b0325893a4..faa63cb400 100644
--- a/src/widgets/widgets/qwidgettextcontrol.cpp
+++ b/src/widgets/widgets/qwidgettextcontrol.cpp
@@ -2281,7 +2281,7 @@ QMenu *QWidgetTextControl::createStandardContextMenu(const QPointF &pos, QWidget
         a->setObjectName(QStringLiteral("select-all"));
     }
 
-    if ((d->interactionFlags & Qt::TextEditable) && qApp->styleHints()->useRtlExtensions()) {
+    if ((d->interactionFlags & Qt::TextEditable) && QGuiApplication::styleHints()->useRtlExtensions()) {
         menu->addSeparator();
         QUnicodeControlCharacterMenu *ctrlCharacterMenu = new QUnicodeControlCharacterMenu(this, menu);
         menu->addMenu(ctrlCharacterMenu);