crash after QJsonArray toVariantList() ...

ttuna

Hi,
my application crashed with following implementation:

template<class T> void Vector<T>::Read(const QJsonObject& io_json)
{
    //Read values
    QJsonArray json_array = io_json[s_JSON_DATA_VALUE].toArray();
    QVariantList variant_list;

   //Qt Bug?
   variant_list = json_array.toVariantList();  //not working (implicit sharing / move semantics problem???)       
   //Qt Bug?
}

If i discard toVariantList() and use a for loop to copy all values from json_array to variant_list everything works fine. Please, could someone help me with that?

Best regards,

SGaist

Hi,

A bit more information is needed to test that. What do you put in io_json ? How do you generate it ?

ttuna

Unfortunately it's a project of a colleague but as far as i know the OJsonObject passed to the function is retrieved from a file using QJsonDocument object() method.

The file looks similar to this:

{
    "min" : -100,
    "max" : 100,
    "val" : [
        45,2,
        34,9,
        17,6
    ]
}

SGaist

Can you show how you are calling that function ?

Can't reproduce your problem from your code and sample data.

What version of Qt are you running ? On what OS ?

Hamed.Masafi

@ttuna said:

variant_list = json_array.toVariantList();

Try this:

variant_list = json_array.toVariantList(QVariantList());

if worked then your json is invalid

ttuna

@Hamed-Masafi
The variant_list is valid after creation. The problem occurs when the Read() function is going to be left.
It seems that a stack object (i tip json_array) will be deleted and produces a crash.

@SGaist
Here are the lines which are calling the Read() function: (i have removed some validity checks)

QFile load_file(load_path);
QByteArray load_data = load_file.readAll();
QJsonDocument load_doc(in_format == Json ? QJsonDocument::fromJson(load_data) : QJsonDocument::fromBinaryData(load_data));
Read(load_doc.object());

SGaist

Can you create minimal compilable example that reproduces the crash ?