Prevent a crash when creating an inputContext from the QApplication dtor.

When accessing the global input context from the QWidget destructor access it
directly instead of calling a helper function.  Don't even bother to create an
input context if QApplication is being destroyed (just in case if the user is
calling the QApplication::inputContext manually from the destructor).

Task-number: QTBUG-7105
Reviewed-by: Simon Hausmann
(cherry picked from commit f72165460d27860cabd51691f4d935fd74b50f80)

2 files changed, 3 insertions, 1 deletions

diff --git a/src/gui/kernel/qapplication.cpp b/src/gui/kernel/qapplication.cpp
index d474391..df36466 100644
--- a/src/gui/kernel/qapplication.cpp
+++ b/src/gui/kernel/qapplication.cpp
@@ -5230,6 +5230,8 @@ QInputContext *QApplication::inputContext() const
 {
     Q_D(const QApplication);
     Q_UNUSED(d);// only static members being used.
+    if (QApplicationPrivate::is_app_closing)
+        return d->inputContext;
 #ifdef Q_WS_X11
     if (!X11)
         return 0;
diff --git a/src/gui/kernel/qwidget_x11.cpp b/src/gui/kernel/qwidget_x11.cpp
index 3135ece..87c9885 100644
--- a/src/gui/kernel/qwidget_x11.cpp
+++ b/src/gui/kernel/qwidget_x11.cpp
@@ -1084,7 +1084,7 @@ void QWidget::destroy(bool destroyWindow, bool destroySubWindows)
         } else {
             // release previous focus information participating with
             // preedit preservation of qic
-            QInputContext *qic = inputContext();
+            QInputContext *qic = QApplicationPrivate::inputContext;
             if (qic)
                 qic->widgetDestroyed(this);
         }