Access and inheritance

tomy

I created a new project called MySpreadsheet and added a few more options to the context menu and renewed the icons to flat ones.
Now when I run the project, it runs normally, but when we close it, the follwoing message is written in the Application Output window:

Starting D:\Projects\Qt\MySpreadsheet\MySpreadsheet\build-MySpreadsheet-Desktop_Qt_5_12_0_MinGW_64_bit-Debug\debug\MySpreadsheet.exe...
FTH: (243752): *** Fault tolerant heap shim applied to current process. This is usually due to previous crashes. ***
The program has unexpectedly finished.
The process was ended forcefully.
D:/Projects/Qt/MySpreadsheet/MySpreadsheet/build-MySpreadsheet-Desktop_Qt_5_12_0_MinGW_64_bit-Debug/debug/MySpreadsheet.exe crashed.

What is the problem please?
Is it not related to the .pro file, please?

jsulm

@tomy Please run through debugger and post stack trace after it crashed...

tomy

@jsulm
Do you mean by pressing F5, please?
If so, I did it, but how to post stack trace?

mrjj

Hi
It is the list to the right we are after

The code
for entries Level 2,3 would help a lot.

tomy

@mrjj,
Hi,

Do you mean I copy and paste code for level 7 and 11 here?
7 is the project's code but 11 includes thousands of lines of code.

mrjj

@tomy
Hi
The line it shows when you click on 11 ? line 1339

tomy

@mrjj, Hi,

Here you are:

mrjj

Hi
it was not what i as i had hoped, it being inside some of the user code.
I wonder if you have a double free.
Did you change anything in main.cpp?

tomy

@mrjj Hi,

Here is main.cpp:

#include "myspreadsheet.h"
#include <QApplication>
#include <QSplashScreen>

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

    QSplashScreen* splash = new QSplashScreen;
    splash->setPixmap(QPixmap(":/images/splash.jpg"));
    splash->show();

    Qt::Alignment topRight = Qt::AlignRight | Qt::AlignTop;
    splash->showMessage(QObject::tr("Setting up the main window..."), topRight, Qt::white);


    MySpreadsheet* mySP = new MySpreadsheet;
    if(argc > 1)
        mySP -> loadFile(argv[1]);

    mySP -> show();
    splash -> finish(mySP);
    delete splash;

    return app.exec();
}

I added those splash stuff and now apparently it's fine!

mrjj

Hi
Does look fine.
Try set breakpoint in main.cpp and press f10 to signle step over it and
see if we can find the reason for the crash.
Since its first on close, it might be inside MySpreadsheet indirectly.

tomy

@mrjj
Hi, It's fine now. :) Thanks so much. :)

mrjj

@tomy
Hi
What was it ? Just to learn also.

tomy

@mrjj Hi,

The faulty one didn't include splash stuff and was this way I think:

#include "myspreadsheet.h"
#include <QApplication>

int main(int argc, char *argv[])
{
    QApplication app(argc, argv);
    MySpreadsheet* mySP = new MySpreadsheet;
    mySP -> show();

    return app.exec();
}

Then I added the splash stuff. Now it "apparently" is fine, but I'm still not sure not do I know of the exact reason for that red message either. :(

SGaist

You are not deleting mySP. The memory will be cleaned up at the end of the application but this doesn't mean that the destructor will be called. So if you have anything there that does something it's not guaranteed to be called.

You should rather keep it on the stack or delete it after returning from app.exec();