diff --git a/doc/src/demos-gdpbarchart.qdoc b/doc/src/demos-gdpbarchart.qdoc
deleted file mode 100644
index 1178f98..0000000
--- a/doc/src/demos-gdpbarchart.qdoc
+++ /dev/null
@@ -1,7 +0,0 @@
-/*!
-     \example demos/gdpbarchart
-     \title GDP bar chart demo
-     \subtitle
-
-     This demo shows how to read Gross domestic product (GDP) data from a sql database and show it in a bar or scatter chart.
-*/
diff --git a/doc/src/demos.qdoc b/doc/src/demos.qdoc
index b696183..9455014 100644
--- a/doc/src/demos.qdoc
+++ b/doc/src/demos.qdoc
@@ -14,7 +14,6 @@
         <td valign="top">
         <ul>
             <li><a href="demos-chartthemes.html">Chart themes</a></li>
-            <li><a href="demos-gdpbarchart.html">GDP bar chart</a></li>
             <li><a href="demos-piechartcustomization.html">Pie chart customization</a></li>
         </ul>
         </td>
diff --git a/src/barchart/qbarseries.cpp b/src/barchart/qbarseries.cpp
index 7055861..e9eb86a 100644
--- a/src/barchart/qbarseries.cpp
+++ b/src/barchart/qbarseries.cpp
@@ -658,7 +658,7 @@ void QBarSeriesPrivate::setModelMapping(int categories, int bottomBoundry, int t
 {
     Q_Q(QBarSeries);
 
-    if (!m_model)
+    if (m_model == 0)
         return;
 
     m_mapCategories = categories;