QLineEdit copy shortcut does not work if isReadonly is true

If you have an application that has a menu item whose shortcut is Cmd-C (or Ctrl-C on Windows) for copy, and also have a QLineEdit that is read only, you can select the text of the QLineEdit but pressing the standard copy shortcut does not copy the selected text to the clipboard. However, right clicking and choosing Copy does copy the text. If the QLineEdit is not read only, then the standard copy keyboard shortcut does copy the text to the clipboard.

This bug is demonstrated in the attachment. If you compile and run it, there are two QLineEdit widgets. The top is editable, the bottom is read only. If you select the text in the top one and press Cmd/Ctrl-C, the text will be copied to the clipboard. If you do the same for the bottom widget, the text is not copied to the clipboard.

The bug looks like it is in QLineControl::processEvent() of qlinecontrol.cpp, where there is this code:

        case QEvent::ShortcutOverride:{
            if (isReadOnly())
                return false;
            QKeyEvent* ke = static_cast<QKeyEvent*>(ev);
            if (ke == QKeySequence::Copy
                || ke == QKeySequence::Paste
                || ke == QKeySequence::Cut
                || ke == QKeySequence::Redo
                || ke == QKeySequence::Undo
                || ke == QKeySequence::MoveToNextWord
                || ke == QKeySequence::MoveToPreviousWord
                || ke == QKeySequence::MoveToStartOfDocument
                || ke == QKeySequence::MoveToEndOfDocument
                || ke == QKeySequence::SelectNextWord
                || ke == QKeySequence::SelectPreviousWord
                || ke == QKeySequence::SelectStartOfLine
                || ke == QKeySequence::SelectEndOfLine
                || ke == QKeySequence::SelectStartOfBlock
                || ke == QKeySequence::SelectEndOfBlock
                || ke == QKeySequence::SelectStartOfDocument
                || ke == QKeySequence::SelectAll
                || ke == QKeySequence::SelectEndOfDocument) {
                ke->accept();

I think ignoring the event in all cases there makes sense for a read only widget except for the copy event.

The attached file was tested on 4.7.2 but this part of qlinecontrol.cpp hasn't changed in the latest version in the Git repo so I expect that the bug still exists.