Uploaded image for project: 'Qt'
  1. Qt
  2. QTBUG-123882

QML list of length N emits (N+1) value change signals when shift() is called

XMLWordPrintable

    • 87cf75dd2 (dev)

      Code

      import QtQuick
import QtQuick.Controls.Basic

Window {
    id: root
    width: 640
    height: 480
    visible: true

    property list<int> numbers: [1, 2, 3, 4, 5]
    onNumbersChanged: console.log("Updated list:", numbers)

    Button {
        text: "Shift"
        onClicked: {
            console.log("=== Starting shift ===")
            root.numbers.shift()
            console.log("=== Finished shift ===")
        }
    }
}

       

      Steps to reproduce
      Run the above code and click the button

       

      Expected outcomes

      qml: === Starting shift ===
qml: Updated list: [2,3,4,5]
qml: === Finished shift ===

       

      Actual outcomes

      qml: === Starting shift ===
qml: Updated list: [2,2,3,4,5]
qml: Updated list: [2,3,3,4,5]
qml: Updated list: [2,3,4,4,5]
qml: Updated list: [2,3,4,5,5]
qml: Updated list: [2,3,4,5,0]
qml: Updated list: [2,3,4,5]
qml: === Finished shift ===

       

      Notes
      There is a similar issue for pop():

      qml: === Starting pop ===
qml: Updated list: [1,2,3,4,0]
qml: Updated list: [1,2,3,4]
qml: === Finished pop ===

        For Gerrit Dashboard: QTBUG-123882
        # Subject Branch Project Status CR V
        562886,4 QtQml: Optimize QV4::Sequence's shift() method dev qt/qtdeclarative Status: MERGED +2 0

            ulherman Ulf Hermann
            skoh-qt Sze Howe Koh
            Votes:
            0 Vote for this issue
            Watchers:
            3 Start watching this issue

              Created:
              Updated:
              Resolved:

                There are no open Gerrit changes