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  1. Qt
  2. QTBUG-138405

Segfault in QQuickTextPrivate if no input method set

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    • Icon: Bug Bug
    • Resolution: Unresolved
    • Icon: P1: Critical P1: Critical
    • None
    • 6.8.0, 6.8.3, 6.9.1
    • Quick: Other
    • None
    • Windows

      QQuickTextPrivate::determineHorizontalAlignment() crashes in if no input method is set.

      #include <QQmlApplicationEngine>
#include <QQmlComponent>
#include <QTest>

class InputMethodCrash : public QObject
{
    Q_OBJECT

private slots:
    void minimalTestCase() {
        auto engine = QQmlApplicationEngine{};
        auto component = QQmlComponent{&engine};
        component.setData("import QtQuick; Text {}", QUrl{});
        QVERIFY2(component.create() != nullptr, qUtf8Printable(component.errorString()));
    }
};

QTEST_MAIN(InputMethodCrash)

#include "main.moc"

      This line is to blame, where QGuiApplication::inputMethod() is used without nullptr check:

              bool alignToRight = text.isEmpty() ? QGuiApplication::inputMethod()->inputDirection() == Qt::RightToLeft : rightToLeftText;

       
      Top of backtrace:

      QInputMethod::inputDirection()
QQuickTextPrivate::determineHorizontalAlignment()
QQuickTextPrivate::determineHorizontalAlignment()
QQuickText::componentComplete()
QQmlObjectCreator::finalize()
...

      Expected behavior: A warning should be printed (if at all), instead of crashing the app.

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            qt.team.quick.subscriptions Qt Quick and Widgets Team
            hasselmann_via_meiller Mathias Hasselmann
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              Created:
              Updated:

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