Using QTableView & QSytledItemDelegate - Issue w/ closeAndCommitEditorLE() :core dump

Qt5
I am using an example straight out the book 'Advanced Qt Programming'

Have a cell in QTableView that when 'double click' generates
a QLineEdit widget where I override the QStyledItemDelegate::createEditor(),
setEditorData(), setModelData() functions. Everything is working fine. However,
the 'core dump' situations arises when the user types in something that is
not allowed ( i.e. certain text words are reserved ) - So I need to notify
the user with a QMessageBox() that this text is reserved. I am not sure
why this is causing the problem:

Here is the code excerpts to show what I am doing:
The core dump occurs in the function closeAndCommitEditorLE()
which is called when the user hits Return in the QLineEdit editor.

It only occurs after a call to issueDuplicateNameWarning() is called
which popups a QMessageBox() warning. I am using exec() to keep things
simple here. When the user clicks on OK the exec() call returns
and my next step is to call: emit closeEditor(pLineEdit). It is
here that the core dump occurs. I have no clue as to why. The stacktrace
is not very clear on what is occurring at this point. I can provide the stacktrace if
anyone would like to see it.

I have been looking at this and debugging for several days and still not sure
why what i am doing is causing such problems. Any feedback, comments or advice
would be much appreciated.

QWidget *DeviceObjectItemDelegate::createEditor(
QWidget *parent,
const QStyleOptionViewItem & option,
const QModelIndex & index ) const
{
if ( index.column() == S_DEV_OBJ_NAME )
{
QLineEdit *pEditor = new QLineEdit(parent);
/* If the user presses Return or Enter, we take this as confirmation
* of their edit.
*/
connect( pEditor, &QLineEdit::returnPressed,
this, &DeviceObjectItemDelegate::closeAndCommitEditorLE) ;
return pEditor;
}
else
{
return QStyledItemDelegate::createEditor( parent, option, index );
}
}

void DeviceObjectItemDelegate::setEditorData(
QWidget *editor,
const QModelIndex & index ) const
{
else if ( index.column() == S_DEV_OBJ_NAME )
{
QString deviceName = index.model()->data(index).toString();
QLineEdit *pLineEdit = qobject_cast<QLineEdit *>(editor);
pLineEdit->setText( deviceName);
}
else
{
QStyledItemDelegate::setEditorData( editor, index );
}
}

void DeviceObjectItemDelegate::setModelData(
QWidget *editor,
QAbstractItemModel *model,
const QModelIndex & index ) const
{
if ( index.column() == S_DEV_OBJ_NAME )
{
QLineEdit *pLineEdit = qobject_cast<QLineEdit *>(editor);
printf( "setModelData[%s]\n", pLineEdit->text().toStdString().c_str() );
model->setData( index, pLineEdit->text() );
}
else
{
QStyledItemDelegate::setModelData( editor, model, index );
}
}

void DeviceObjectItemDelegate:: closeAndCommitEditorLE()
{
QLineEdit *pLineEdit = qobject_cast<QLineEdit*>(sender() );
QString Name = pLineEdit->text();
m_pLineEditor = pLineEdit;

bool bIsDuplicate = m_pDuplicateDeviceNames->doesNameAlreadyExist(m_deviceType ,
m_tableType, Name );

if ( bIsDuplicate)
{
/* Name already exists - alert the user */
issueDuplicateNameWarning( Name );
/* ERROR OCCURS WHEN THE NEXT LINE IS EXECUTED */
emit closeEditor( pLineEdit);
emit clearOkToUpdateFlag();
return;
}

setFlag( true );

emit commitData( pLineEdit);
emit closeEditor( pLineEdit);
emit clearOkToUpdateFlag();
}

void DeviceObjectItemDelegate:: issueDuplicateNameWarning(
const QString & Name )
{
QMessageBox msgBox;
msgBox.setIcon(QMessageBox::Warning);
msgBox.setWindowTitle("Device Type Name - Duplicate" );
msgBox.setText("Duplicate Device Type Names are NOT allowed!");
msgBox.setInformativeText(tr("The Device Type Name [%1] is already in use.").arg(Name));
msgBox.exec();
}