Debugger: Don't fetch more data for console after engine shutdown

The engine might not exist anymore.

Change-Id: I7a542de7fb8b160d71a1650d37263e4433f97003
Reviewed-by: hjk <hjk@qt.io>

src/plugins/debugger/console/console.cpp

@@ -249,6 +249,7 @@ void Console::writeSettings() const
 void Console::setScriptEvaluator(const ScriptEvaluator &evaluator)
 {
     m_scriptEvaluator = evaluator;
+    m_consoleItemModel->setCanFetchMore(bool(m_scriptEvaluator));
     if (!m_scriptEvaluator)
         setContext(QString());
 }

src/plugins/debugger/console/consoleitemmodel.cpp

@@ -39,7 +39,7 @@ namespace Internal {
 
 ConsoleItemModel::ConsoleItemModel(QObject *parent) :
     Utils::TreeModel<>(new ConsoleItem, parent),
-    m_maxSizeOfFileName(0)
+    m_maxSizeOfFileName(0), m_canFetchMore(false)
 {
     clear();
 }
@@ -51,6 +51,16 @@ void ConsoleItemModel::clear()
     emit selectEditableRow(index(0, 0, QModelIndex()), QItemSelectionModel::ClearAndSelect);
 }
 
+void ConsoleItemModel::setCanFetchMore(bool canFetchMore)
+{
+    m_canFetchMore = canFetchMore;
+}
+
+bool ConsoleItemModel::canFetchMore(const QModelIndex &parent) const
+{
+    return m_canFetchMore && TreeModel::canFetchMore(parent);
+}
+
 void ConsoleItemModel::appendItem(ConsoleItem *item, int position)
 {
     if (position < 0)

src/plugins/debugger/console/consoleitemmodel.h

@@ -53,11 +53,15 @@ public:
 
     void clear();
 
+    void setCanFetchMore(bool canFetchMore);
+    bool canFetchMore(const QModelIndex &parent) const override;
+
 signals:
     void selectEditableRow(const QModelIndex &index, QItemSelectionModel::SelectionFlags flags);
 
 private:
     int m_maxSizeOfFileName;
+    bool m_canFetchMore;
 };
 
 } // Internal