Unable to set value of default dynamic properties in Designer's property editor

The default Designer property sheet (qdesigner_propertysheet.cpp) distinguishes between DynamicProperties and DefaultDynamicProperties. Both types of properties are visible in the property editor, but setting the value of DefaultDynamicProperties does not work correctly.

The attached file creates a simple custom QPushButton that will set its text according to the value of a dynamic property. The file also creates a plugin to use the widget in Designer.

Expected: Create a new form and add a DefaultDynamicPropertyTestWidget. Then change the value of the "aDynamicProperty" property in Designer's property editor. The button text should update.

Observed: The button text does not update.

The following change to qdesigner_propertysheet.cpp fixes this specific incorrect behavior:

— qdesigner_propertysheet.cpp.orig
+++ qdesigner_propertysheet.cpp
@@ -1127,7 +1127,7 @@
}
}

• if (isDynamicProperty(index)) {
  + if (isDynamicProperty(index) || isDefaultDynamicProperty(index)) {
  if (d->isResourceProperty(index))
  d->setResourceProperty(index, value);
  if (d->isStringProperty(index))

However, I suspect that the issue is more complex than this fix: note that the initial value of the dynamic property is also incorrect.