ASSERT failure in QList<T>::at: "index out of range"

[Qjay]

@Paul @SGaist , i don't know why but i am never able to initialize QUrl url :( ;

AND I BELIEVE THAT"S WHAT CAUSING THE PROBLEM

i have tried different approaches too . Like in my code i was using QStringList i even tried Qvector<QString> down_links and end result was same

NOT ABLE TO set QUrl

in console screen
QUrl("")
""

What shoudl i do ?

[jsulm]

@Qjay Can you show the code where you initialize QUrl? From your description we can only guess what could be the problem. Are you sure you don't pass an empty string to QUrl?

[Qjay]

@jsulm , i have given the whole code

https://ghostbin.com/paste/v4t47

by the way this is where i set QUrl

line no 371

 QUrl url = v.toStringList().at(current);
        qDebug() << "why break" << url;

[SGaist]

Again, did you check that the value of current is lower than the size of the string list ?

[Qjay]

I have initialized current =0; in global scope .

[jsulm]

@Qjay But is it changed somewhere?
Why not just check like this?

qDebug() << v.toStringList().size() << current;
qDebug() << v.toStringList().at(current);
QUrl url = v.toStringList().at(current);

In such a situation this is actually the first thing to do...

[Qjay]

hey @jsulm

i tried what you suggested

qDebug() << v.toStringList().size() << current;
qDebug() << v.toStringList().at(current);
QUrl url = v.toStringList().at(current);

i did this

qDebug() << "stringlist size and current" << v.toStringList().size() << current;
        qDebug() << "current url in stringlist" << v.toStringList().at(current);
        QUrl url = v.toStringList().at(current);
        qDebug() << "why break" << url;

output

stringlist size and current 33 0
current url in stringlist   "(http://restbase.wikitolearn.org/en.wikitolearn.org/v1/media/math/render/svg/3cd95482da53d42c5f7f249454f7ee1e85cacc0c)"
why break QUrl("")
""

and then error

ASSERT failure in QList<T>::at: "index out of range", file ../../Qt5.7.0/5.7/gcc_64/include/QtCore/qlist.h, line 537
The program has unexpectedly finished.

[jsulm]

@Qjay Why is the URL in parentheses?

(http://restbase.wikitolearn.org/en.wikitolearn.org/v1/media/math/render/svg/3cd95482da53d42c5f7f249454f7ee1e85cacc0c)

[SGaist]

Looks like you are doing a lot of parsing, replacement etc.

The first thing I'd do, is to just ensure that you really have URLs in your list. And get rid of that QVariant parameter. It really doesn't make any sense in your use case.

[Qjay]

Hello , thanks for the suggetions .

1. yes there were useless ( ) in url . i have removed them . Now i am able to assign url to Qurl :D great!!

2. i removed the Qvariant thing too

now the code is

.cpp : https://ghostbin.com/paste/vv2w7

header file : https://ghostbin.com/paste/8z4y3

but the assert error still exist :/

[SGaist]

Still at the same place ?

[Qjay]

Hey @SGaist , @jsulm , thank you it's solved now

To be honest i don't know why it worked :/

but below is the code

https://ghostbin.com/paste/528m6

[SGaist]

From the looks of it, you're currently lucky.

I'd recommend considering refactoring and cleaning up this code. Maybe a full rewrite would even be better.

[Qjay]

I too was also thinking of full rewrite but i don't have much time for that right now :/ .