Qt 5.3 QML Application crashes with associative array

Maxwell77

Since 5.3 an QML application crashes if I'm using an associative array with more than 10 elements. With 10 or less elements, the application works. With Qt 5.2 this wasn't an issue

@import QtQuick 2.2

Rectangle {
width: 360
height: 360

property variant colors: {
            "0": "#80ffd618",
            "2": "#80c21717",
            "5": "#8076210e",
            "8": "#80faea3b",
            "6": "#8076210e",
            "12": "#809c831f",
            "13": "#80baae2d",
            "16": "#805e2722",
            "18": "#805e2532",
            "39": "#80cd5834",
            "40": "#80c20f2e"
}

Text {
    anchors.centerIn: parent
    text: "Hello World"
    color: colors["40"]
}

}@

sierdzio

Looks like a bug, please report it on "Jira":https://qt-project.org/wiki/ReportingBugsInQt.

Xander84

are you sure that worked before? I could never get it to work to assign objects to properties directly. I thought that is a feature of QML and the {} are parsed as a function like you do with slots (onClicked: {} is a slot and not an JS object as far as I know).

So with Qt 5.2 and 5.2.1 it is a QMl syntax error to do something like
@
property var foo: {}
@
or do you have to use variant in that case? I thought you should always use "var" instead of variant in newer version of Qt?

anyway my solution is to use a helper function that always works:
@
property var foo: getFoo()
function getFoo() {
return { ... }
}
@

chrisadams

Braces in property initialisations are treated as binding expression delimiters. You need to wrap them in parentheses or explicitly call the Object constructor function to achieve the behaviour you want.

property variant foo: ({ "something": 1 })
property variant bar: { var temp = new Object(); temp.something = 1; return temp; }

Cheers,
Chris.

Maxwell77

Thanks for reply. I'm sure it is working in 5.2. I migrated an application from 5.2 to 5.3 and the same application is still working with Qt 5.2

Even the above changes from variant to var, the definition of a function or wrapping with parentheses does not change anything. The application crashes too.

The associative array works with 10 or less elements. Only with more than 10 elements the application crashes.

Xander84

maybe the crash is related to something else then, did you take a look at the stacktrace when the app crashes and where exactly it does.

Maxwell77

No, it's related to the associative array.
Qt provided already a fix https://codereview.qt-project.org/#change,82113