Property recursion panic when having changed event on geometry property in a layout with condition

[zhuyu4839]

Bug Description

Crash when enable all of change height at line 8 and VerticalLayout at line 21 and for loop at line 27.

Reproducible Code (if applicable)

import { ScrollView } from "std-widgets.slint";

component MyBox inherits Rectangle {
    preferred-height: 100px;
    preferred-width: 100px;
    background: red;

    changed height => {}    // TODO crash
}

export component AppWindow inherits Window {
    title: "Slint Demo";
//    icon: @image-url("app.svg");
    preferred-width: 1280px;
    preferred-height: 720px;
    default-font-size: 14px;

    ScrollView {
        vertical-scrollbar-policy: always-off;

        VerticalLayout {    // TODO crash
            Rectangle {
                VerticalLayout {
                    alignment: start;
                    padding-top: 20px;
                    MyBox {}    // TODO no crash
                    for i in 5: gb := MyBox {}  // TODO crash
                }
            }
        }
    }
}

Environment Details

• Slint Version: 1.10.0
• Platform/OS: Windows 10 LTSC 2019
• Programming Language: Rust
• Backend/Renderer: ...

Product Impact

No response

[zhuyu4839]

Crash when preview by RustRover plugin except VSCode plugin.

[hunger]

Slintpad crashes (both 1.10 and master), too, with this message in the web developer console:

panicked at /home/runner/work/slint/slint/internal/core/properties.rs:523:9:
Recursion detected

[hunger]

This is the smallest I could reduce the example down to:

export component AppWindow inherits Window {
    VerticalLayout {
        Rectangle {
            changed height => {}
        }
        if true: Rectangle {
            changed height => {}
        }
    }
}

[ogoffart]

Quite similar to #7402
initializing the change event basically query the property as the change tracker are initialized

[novakduc]

Just a small add-on. If we use VerticalLayout as the parent component, we get a crash with changed height callback function. With HorizontalLayout, it happens when with changed width callback.