Legend identifiers disappear after inserting widget

[orignihn]

Hello all,

I'm using Qwt 5.2.1 to plot some data in a subclass of QwtPlot. I have the following code:

QwtPlotCurve* curve = new QwtPlotCurve("Variable");
curve->attach(this);
 
legend()->insert(curve, new QLabel());

QwtPlotCurve* curve = new QwtPlotCurve("Variable");
curve->attach(this);

legend()->insert(curve, new QLabel());

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There's a bunch of other code being executed, but the problem seems to be the legend()->insert() call. If I comment that line out, I get a nice display of the curve's line, symbol, and text (as per the identifierMode() that is set). If that line is left in, the line and symbol display disappear. I check the identifierMode() on each plot update, and it is equal to 7 (QwtLegendItem::ShowLine | QwtLegendItem::ShowSymbol | QwtLegendItem::ShowText) each time. When the insert() call is left in, I can update the QLabel just fine.

How do I get both the QLabel and the curve's symbol and line into the legend?

Thanks,
- Tom