ViewPrivate::contextMenu() has a surprising way of handling the ktexteditor_popup menu aboutToXXX signals: it disconnects them from the current ViewPrivate instance and then reconnects them to the same instance.

I think the disconnect should be from all receivers that were once connected to the menu show & hide signals. Doing that resolves the issue where ViewPrivate::aboutToShowContextMenu() is called for all open KTextEditorViews that once had the context menu open, instead of only for the view that is currently active.

BUG: 401069

Build KTextEditor with a debug trace to ViewPrivate::aboutToShowContextMenu(), e.g.

void KTextEditor::ViewPrivate::aboutToShowContextMenu()
{
    QMenu *menu = qobject_cast<QMenu *>(sender());

    if (menu) {
        if (mainWindow()->activeView() == this) {
            qWarning() << Q_FUNC_INFO << "emitting contextMenuAboutToShow for foreground view" << this;
            emit contextMenuAboutToShow(this, menu);
        } else {
            qWarning() << Q_FUNC_INFO << "NOT emitting contextMenuAboutToShow for background view" << this;
        }
    }
}

Now open Kate with multiple documents. Right-click in the active document, notice only that view emits contextMenuAboutToShow. Activate other documents one after the other, right-clicking in them, and notice how the previously active documents would have emitted the contextMenuAboutToShow signal.

This is resolved by applying this patch. Opening the context menu in a long-running multi-document session keeps feeling snappier during the entire session too.