Wt

Widgets added to a WGroupBox using addWidget() or addNew<>() are silently not rendered.
This is visible in the Wt Widget Gallery, where the Group Box example displays only the fieldset frame and legend — the child widgets inside are invisible; screenshot shown in attached jpg.

WGroupBox::init() calls setLogicalLayout(nullptr), which unconditionally creates a WVBoxLayout wrapper and passes it to WContainerWidget::setLogicalLayout(), even when the argument is nullptr.
This sets WContainerWidget::layout_ to a non-null but empty WVBoxLayout.

The fix is to only create the WVBoxLayout wrapper and call the parent setLogicalLayout() when a real layout is provided. When called with nullptr (as in init()), just initialize logicalLayout_ without creating a wrapper layout.

I think the attached patch fixes the issue.

thank you