[netinstall] Hidden groups follow selectedness of parents.

If a subgroup is hidden, then it should be considered
selected if its parent is selected or partially-selected.
If the parent group is totally unselected, then the hidden
subgroup shouldn't be installed either. This allows putting
required-packages into a group, without cluttering the
interface.

FIXES #864

src/modules/netinstall/PackageModel.cpp

@@ -163,6 +163,7 @@ PackageModel::getPackages() const
 {
     QList<PackageTreeItem*> items = getItemPackages( m_rootItem );
     for ( auto package : m_hiddenItems )
+        if ( package->hiddenSelected() )
             items.append( getItemPackages( package ) );
     QList<PackageTreeItem::ItemData> packages;
     for ( auto item : items )

src/modules/netinstall/PackageTreeItem.cpp

@@ -101,6 +101,13 @@ PackageTreeItem::parentItem()
     return m_parentItem;
 }
 
+const PackageTreeItem*
+PackageTreeItem::parentItem() const
+{
+    return m_parentItem;
+}
+
+
 QString
 PackageTreeItem::prettyName() const
 {
@@ -143,6 +150,26 @@ PackageTreeItem::setHidden( bool isHidden )
     m_data.isHidden = isHidden;
 }
 
+bool
+PackageTreeItem::hiddenSelected() const
+{
+    Q_ASSERT( m_data.isHidden );
+    if (! m_data.selected )
+        return false;
+
+    const PackageTreeItem* currentItem = parentItem();
+    while ( currentItem != nullptr )
+    {
+        if ( !currentItem->isHidden() )
+            return currentItem->isSelected() != Qt::Unchecked;
+        currentItem = currentItem->parentItem();
+    }
+
+    /* Has no non-hiddent parents */
+    return m_data.selected;
+}
+
+
 bool
 PackageTreeItem::isCritical() const
 {

src/modules/netinstall/PackageTreeItem.h

@@ -49,16 +49,30 @@ public:
     int columnCount() const;
     QVariant data( int column ) const override;
     int row() const;
+
     PackageTreeItem* parentItem();
+    const PackageTreeItem* parentItem() const;
+
     QString prettyName() const;
     QString description() const;
     QString preScript() const;
     QString packageName() const;
     QString postScript() const;
+
     bool isHidden() const;
     void setHidden( bool isHidden );
+    /**
+     * @brief Is this hidden item, considered "selected"?
+     *
+     * This asserts when called on a non-hidden item.
+     * A hidden item has its own selected state, but really
+     * falls under the selectedness of the parent item.
+     */
+    bool hiddenSelected() const;
+
     bool isCritical() const;
     void setCritical( bool isCritical );
+
     Qt::CheckState isSelected() const;
     void setSelected( Qt::CheckState isSelected );
     void setChildrenSelected( Qt::CheckState isSelected );