Crash with Qt6.11.1 and VerticalHeaderView

[DuBu]

Hi,

I've got the following example code:
main.cpp:

#include "tablemodel.h"
#include <QGuiApplication>
#include <QQmlApplicationEngine>

int main(int argc, char *argv[]) {
  QGuiApplication app(argc, argv);

  qmlRegisterType<TableModel>("Models", 1, 0, "TableModel");

  QQmlApplicationEngine engine;
  QObject::connect(
      &engine, &QQmlApplicationEngine::objectCreationFailed, &app, []() { QCoreApplication::exit(-1); },
      Qt::QueuedConnection);
  engine.loadFromModule("MatrixView", "Main");

  return QGuiApplication::exec();
}

tablemodel.h:

#pragma once

#include <QAbstractTableModel>

class TableModel : public QAbstractTableModel {
public:
  enum RoleNames { NameRole = Qt::UserRole };
  explicit TableModel(QObject *parent = nullptr) : QAbstractTableModel{parent} {}

  // QAbstractItemModel interface
public:
  int rowCount(const QModelIndex &parent) const override { return 2; }
  int columnCount(const QModelIndex &parent) const override { return 2; }
  QVariant data(const QModelIndex &index, int role) const override { return ""; }
  QVariant headerData(int section, Qt::Orientation orientation, int role) const override { return ""; }
  QHash<int, QByteArray> roleNames() const override { return {{NameRole, "name"}}; }  // #1
};

Main.qml:

import QtQuick
import QtQuick.Controls
import Models

ApplicationWindow {
    visible: true
    width: 640
    height: 480
    title: qsTr("HeaderView")

    VerticalHeaderView {
        id: vhv
        anchors.top: tv.top
        syncView: tv
        textRole: 'name' // #2
    }

    TableView {
        id: tv
        anchors.left: vhv.right
        anchors.top: parent.top
        anchors.right: parent.right
        anchors.bottom: parent.bottom

        columnSpacing: 1
        rowSpacing: 1

        model: TableModel {}

        delegate: Rectangle {
            implicitWidth: 40
            implicitHeight: 20
            color: 'black'
            Label {
                anchors.fill: parent
                text: name // #3
                color: 'white'
                horizontalAlignment: Label.AlignHCenter
                verticalAlignment: Label.AlignVCenter
            }
        }
    }
}

When I run this, the app crashes with:

appMatrixView(27748,0x1f5466180) malloc: *** error for object 0xc01927bf8: pointer being freed was not allocated
appMatrixView(27748,0x1f5466180) malloc: *** set a breakpoint in malloc_error_break to debug
[1]    27748 abort

Everything works, if I change the lines in the code like this:

• delete line #1 and #2
• change line #3 to:

text: display

Whats goint on there? Any help is very appreciated!

Cheers!

[SGaist]

Hi,

One thing I would do is to return a QVariant() rather than an empty string in your model data and headerData functions. I am not saying that this is the right solution but the model will be queried for more than a single role and not all of them uses strings.

[JoeCFD]

Although I can build with meson and run your code on Ubuntu 22.04, TableModel needs Q_OBJECT macro.
qmake6 --version
QMake version 3.1
Using Qt version 6.11.1 in /opt/Qt6/6.11.1/gcc_64/lib

[DuBu]

@SGaist said in Crash with Qt6.11.1 and VerticalHeaderView:

Hi,

One thing I would do is to return a QVariant() rather than an empty string in your model data and headerData functions. I am not saying that this is the right solution but the model will be queried for more than a single role and not all of them uses strings.

This is just a minimal example. The string will be implicitly converted to a QVariant, but with an empty QVariant() I get QML warnings for the line marked with //#3 ("Can't convert undefined to string"). I also added a "qDebug() << role" line to data() to see what roles this function get called with and since I have only one role "NameRole" it only get called with this role only. But anyway it doesn't fix the crash.

[DuBu]

@JoeCFD said in Crash with Qt6.11.1 and VerticalHeaderView:

Although I can build with meson and run your code on Ubuntu 22.04, TableModel needs Q_OBJECT macro.
qmake6 --version
QMake version 3.1
Using Qt version 6.11.1 in /opt/Qt6/6.11.1/gcc_64/lib

I use Qt 6.11.1 on macOS. This project is a cmake project and was created with the project template of Qt Creator. The lines I showed are the only changes I made. And building works fine, it just doesn't run.
Are you sure about the Q_OBJECT? I thought Q_OBJECT is only needed, when I use Q_PROPERTY, signals or slots. But anyway, adding Q_OBJECT doesn't stop it from crashing.

[SGaist]

Can you test with 6.12 ?

I just did and your code is working without issue.

[DuBu]

@SGaist said in Crash with Qt6.11.1 and VerticalHeaderView:

Can you test with 6.12 ?

I just did and your code is working without issue.

6.12.0-beta2?

[SGaist]

@DuBu yes please.

[DuBu]

@DuBu said in Crash with Qt6.11.1 and VerticalHeaderView:

@SGaist said in Crash with Qt6.11.1 and VerticalHeaderView:

Can you test with 6.12 ?

I just did and your code is working without issue.

6.12.0-beta2?

It seems, I can't:

Undefined symbols for architecture arm64:
  "QQmlPrivate::AOTLookupValidation::validateLookupSignature(QQmlEngine*, QV4::CompiledData::CompilationUnit*, QQmlPrivate::AOTLookupValidation::Lookup const&, std::variant<QQmlPrivate::AOTLookupValidation::PropertySignature, QQmlPrivate::AOTLookupValidation::EnumKeySignature, QQmlPrivate::AOTLookupValidation::MethodSignature> const&)", referenced from:
      QmlCacheGeneratedCode::_qt_qml_MatrixView_Main_qml::validateLookupSignatures(QQmlEngine*, QV4::CompiledData::CompilationUnit*) in appMatrixView_Main_qml.cpp.o
ld: symbol(s) not found for architecture arm64
collect2: error: ld returned 1 exit status

[JoeCFD]

@DuBu your model will not update in your qml gui without Q_OBJECT macro in TableModel. I did not change anything in your code and it works on ubuntu .