ProjectExplorer: Fix undefined behavior regarding ShowMoreItem

Introduce ITargetItem interface for TargetItem and ShowMoreItem.

Fixes: QTCREATORBUG-31074
Change-Id: I8aa15b985ac3a18b44169f93520057837e1718ea
Reviewed-by: Christian Kandeler <christian.kandeler@qt.io>

src/plugins/projectexplorer/targetsettingspanel.cpp

@@ -194,11 +194,38 @@ public:
     TargetSetupPageWrapper *m_targetSetupPageWrapper = nullptr;
 };
 
-class ShowMoreItem : public TreeItem
+class ITargetItem : public TypedTreeItem<TreeItem, TargetGroupItem>
+{
+public:
+    enum { DefaultPage = 0 }; // Build page.
+
+    ITargetItem(Project *project, Id kitId, const Tasks &issues)
+        : m_project(project)
+        , m_kitId(kitId)
+        , m_kitIssues(issues)
+    {}
+
+    virtual Target *target() const = 0;
+    virtual void updateSubItems() = 0;
+    virtual void addToContextMenu(QMenu *menu, bool isSelectable) = 0;
+
+    bool isEnabled() const { return target() != nullptr; }
+
+public:
+    QPointer<Project> m_project; // Not owned.
+    Id m_kitId;
+    int m_currentChild = DefaultPage;
+    bool m_kitErrorsForProject = false;
+    bool m_kitWarningForProject = false;
+    Tasks m_kitIssues;
+};
+
+class ShowMoreItem : public ITargetItem
 {
 public:
     ShowMoreItem(TargetGroupItemPrivate *p)
-        : m_p(p)
+        : ITargetItem(nullptr, Id(), Tasks())
+        , m_p(p)
     {}
 
     QVariant data(int column, int role) const override
@@ -230,6 +257,13 @@ public:
         return Qt::ItemIsEnabled | Qt::ItemIsEditable | Qt::ItemIsSelectable;
     }
 
+    // ITargetItem
+    Target *target() const override {
+        return nullptr;
+    }
+    void updateSubItems() override {}
+    void addToContextMenu(QMenu *, bool) override {}
+
 private:
     TargetGroupItemPrivate *m_p;
 };
@@ -274,13 +308,11 @@ void TargetGroupItemPrivate::ensureWidget()
 //
 // Third level: The per-kit entries (inactive or with a 'Build' and a 'Run' subitem)
 //
-class TargetItem : public TypedTreeItem<TreeItem, TargetGroupItem>
+class TargetItem : public ITargetItem
 {
 public:
-    enum { DefaultPage = 0 }; // Build page.
-
     TargetItem(Project *project, Id kitId, const Tasks &issues)
-        : m_project(project), m_kitId(kitId), m_kitIssues(issues)
+        : ITargetItem(project, kitId, issues)
     {
         m_kitWarningForProject = containsType(m_kitIssues, Task::TaskType::Warning);
         m_kitErrorsForProject = containsType(m_kitIssues, Task::TaskType::Error);
@@ -288,12 +320,12 @@ public:
         updateSubItems();
     }
 
-    Target *target() const
+    Target *target() const override
     {
         return m_project->target(m_kitId);
     }
 
-    void updateSubItems();
+    void updateSubItems() override;
 
     Qt::ItemFlags flags(int column) const override
     {
@@ -332,7 +364,7 @@ public:
 
         case Qt::FontRole: {
             QFont font = parent()->data(column, role).value<QFont>();
-            if (TargetItem *targetItem = parent()->currentTargetItem()) {
+            if (ITargetItem *targetItem = parent()->currentTargetItem()) {
                 Target *t = targetItem->target();
                 if (t && t->id() == m_kitId && m_project == ProjectManager::startupProject())
                     font.setBold(true);
@@ -384,7 +416,7 @@ public:
                 m_project->addTargetForKit(KitManager::kit(m_kitId));
             } else {
                 // Go to Run page, when on Run previously etc.
-                TargetItem *previousItem = parent()->currentTargetItem();
+                ITargetItem *previousItem = parent()->currentTargetItem();
                 m_currentChild = previousItem ? previousItem->m_currentChild : DefaultPage;
                 m_project->setActiveTarget(target(), SetActive::Cascade);
                 parent()->setData(column, QVariant::fromValue(static_cast<TreeItem *>(this)),
@@ -413,7 +445,7 @@ public:
         return false;
     }
 
-    void addToContextMenu(QMenu *menu, bool isSelectable)
+    void addToContextMenu(QMenu *menu, bool isSelectable) override
     {
         Kit *kit = KitManager::kit(m_kitId);
         QTC_ASSERT(kit, return);
@@ -493,16 +525,6 @@ public:
         }
     }
 
-    bool isEnabled() const { return target() != nullptr; }
-
-public:
-    QPointer<Project> m_project; // Not owned.
-    Id m_kitId;
-    int m_currentChild = DefaultPage;
-    bool m_kitErrorsForProject = false;
-    bool m_kitWarningForProject = false;
-    Tasks m_kitIssues;
-
 private:
     enum class IconOverlay {
         Add,
@@ -744,13 +766,13 @@ QVariant TargetGroupItem::data(int column, int role) const
         return d->m_displayName;
 
     if (role == ActiveItemRole) {
-        if (TargetItem *item = currentTargetItem())
+        if (ITargetItem *item = currentTargetItem())
             return item->data(column, role);
         return QVariant::fromValue<TreeItem *>(const_cast<TargetGroupItem *>(this));
     }
 
     if (role == PanelWidgetRole) {
-        if (TargetItem *item = currentTargetItem())
+        if (ITargetItem *item = currentTargetItem())
             return item->data(column, role);
 
         d->ensureWidget();
@@ -776,16 +798,16 @@ Qt::ItemFlags TargetGroupItem::flags(int) const
     return Qt::NoItemFlags;
 }
 
-TargetItem *TargetGroupItem::currentTargetItem() const
+ITargetItem *TargetGroupItem::currentTargetItem() const
 {
     return targetItem(d->m_project->activeTarget());
 }
 
-TargetItem *TargetGroupItem::targetItem(Target *target) const
+ITargetItem *TargetGroupItem::targetItem(Target *target) const
 {
     if (target) {
         Id needle = target->id(); // Unconfigured project have no active target.
-        return findFirstLevelChild([needle](TargetItem *item) { return item->m_kitId == needle; });
+        return findFirstLevelChild([needle](ITargetItem *item) { return item->m_kitId == needle; });
     }
     return nullptr;
 }
@@ -854,7 +876,7 @@ void TargetGroupItemPrivate::rebuildContents()
 
 void TargetGroupItemPrivate::handleTargetAdded(Target *target)
 {
-    if (TargetItem *item = q->targetItem(target))
+    if (ITargetItem *item = q->targetItem(target))
         item->updateSubItems();
     ensureShowMoreItem();
     q->update();
@@ -862,7 +884,7 @@ void TargetGroupItemPrivate::handleTargetAdded(Target *target)
 
 void TargetGroupItemPrivate::handleTargetRemoved(Target *target)
 {
-    if (TargetItem *item = q->targetItem(target))
+    if (ITargetItem *item = q->targetItem(target))
         item->updateSubItems();
     ensureShowMoreItem();
     q->parent()->setData(0, QVariant::fromValue(static_cast<TreeItem *>(q)),
@@ -871,7 +893,7 @@ void TargetGroupItemPrivate::handleTargetRemoved(Target *target)
 
 void TargetGroupItemPrivate::handleTargetChanged(Target *target)
 {
-    if (TargetItem *item = q->targetItem(target))
+    if (ITargetItem *item = q->targetItem(target))
         item->updateSubItems();
     ensureShowMoreItem();
     q->setData(0, QVariant(), ItemActivatedFromBelowRole);

src/plugins/projectexplorer/targetsettingspanel.h

@@ -15,11 +15,11 @@ class Target;
 
 namespace Internal {
 
-class TargetItem;
+class ITargetItem;
 class TargetGroupItemPrivate;
 
 // Second level: Special case for the Build & Run item (with per-kit subItems)
-class TargetGroupItem : public Utils::TypedTreeItem<TargetItem /*, ProjectItem */>
+class TargetGroupItem : public Utils::TypedTreeItem<ITargetItem /*, ProjectItem */>
 {
 public:
     TargetGroupItem(const QString &displayName, Project *project);
@@ -29,8 +29,8 @@ public:
     bool setData(int column, const QVariant &data, int role) override;
     Qt::ItemFlags flags(int) const override;
 
-    TargetItem *currentTargetItem() const;
+    ITargetItem *currentTargetItem() const;
-    TargetItem *targetItem(Target *target) const;
+    ITargetItem *targetItem(Target *target) const;
 
 private:
     const std::unique_ptr<TargetGroupItemPrivate> d;