diff --git a/src/barchart/qbarmodelmapper.cpp b/src/barchart/qbarmodelmapper.cpp
index 1341061..d861b9a 100644
--- a/src/barchart/qbarmodelmapper.cpp
+++ b/src/barchart/qbarmodelmapper.cpp
@@ -87,6 +87,7 @@ void QBarModelMapper::reset()
     m_mapBarBottom = -1;
     m_mapBarTop = -1;
     m_mapCategories = -1;
+    emit updated();
 }
 
 #include "moc_qbarmodelmapper.cpp"
diff --git a/src/barchart/qbarseries.cpp b/src/barchart/qbarseries.cpp
index f94a1cb..ef42173 100644
--- a/src/barchart/qbarseries.cpp
+++ b/src/barchart/qbarseries.cpp
@@ -255,7 +255,7 @@ void QBarSeries::setModelMapper(QBarModelMapper *mapper)
     if (mapper) {
         d->m_mapper = mapper;
         // connect the signal from the mapper
-        connect(d->m_mapper, SIGNAL(updated()), d, SLOT(initializePieFromModel()));
+        connect(d->m_mapper, SIGNAL(updated()), d, SLOT(initializeDataFromModel()));
 
         if (d->m_model)
             d->initializeDataFromModel();
@@ -436,6 +436,9 @@ qreal QBarSeriesPrivate::maxCategorySum()
 
 void QBarSeriesPrivate::modelUpdated(QModelIndex topLeft, QModelIndex bottomRight)
 {
+    if (m_model == 0 || m_mapper == 0)
+        return;
+
     for (int row = topLeft.row(); row <= bottomRight.row(); row++) {
         for (int column = topLeft.column(); column <= bottomRight.column(); column++) {
             if (m_mapper->orientation() == Qt::Vertical)
@@ -480,14 +483,21 @@ void QBarSeriesPrivate::initializeDataFromModel()
 {
     Q_Q(QBarSeries);
 
-    if (m_model == 0 || m_mapper == 0)
-        return;
-
     // create the initial bars
     m_categories.clear();
     m_barSets.clear();
+
+    if (m_model == 0 || m_mapper == 0)
+        return;
+
+    // check if mappings are set
+    if (m_mapper->mapBarBottom() == -1 || m_mapper->mapBarTop() == -1 || m_mapper->mapCategories() == -1)
+        return;
+
     //    emit restructuredBars();
     if (m_mapper->orientation() == Qt::Vertical) {
+        if (m_mapCategories >= m_model->columnCount())
+            return;
         int rowCount = 0;
         if(m_mapper->count() == -1)
             rowCount = m_model->rowCount() - m_mapper->first();
@@ -497,13 +507,17 @@ void QBarSeriesPrivate::initializeDataFromModel()
             m_categories << m_model->data(m_model->index(k, m_mapper->mapCategories()), Qt::DisplayRole).toString();
         }
 
-        for (int i = m_mapper->mapBarBottom(); i <= m_mapper->mapBarTop(); i++) {
+        int lastAvailableBarSet = qMin(m_model->columnCount() - 1, m_mapper->mapBarTop());
+        for (int i = m_mapper->mapBarBottom(); i <= lastAvailableBarSet; i++) {
+//        for (int i = m_mapper->mapBarBottom(); i <= m_mapper->mapBarTop(); i++) {
             QBarSet* barSet = new QBarSet(m_model->headerData(i, Qt::Horizontal, Qt::DisplayRole).toString());
             for(int m = m_mapper->first(); m < m_mapper->first() + rowCount; m++)
                 *barSet << m_model->data(m_model->index(m, i), Qt::DisplayRole).toDouble();
             q->appendBarSet(barSet);
         }
     } else {
+        if (m_mapCategories >= m_model->rowCount())
+            return;
         int columnCount = 0;
         if(m_mapper->count() == -1)
             columnCount = m_model->columnCount() - m_mapper->first();
@@ -513,7 +527,9 @@ void QBarSeriesPrivate::initializeDataFromModel()
             m_categories << m_model->data(m_model->index(m_mapper->mapCategories(), k), Qt::DisplayRole).toString();
         }
 
-        for (int i = m_mapper->mapBarBottom(); i <= m_mapper->mapBarTop(); i++) {
+        int lastAvailableBarSet = qMin(m_model->rowCount() - 1, m_mapper->mapBarTop());
+        for (int i = m_mapper->mapBarBottom(); i <= lastAvailableBarSet; i++) {
+//        for (int i = m_mapper->mapBarBottom(); i <= m_mapper->mapBarTop(); i++) {
             QBarSet* barSet = new QBarSet(m_model->headerData(i, Qt::Vertical, Qt::DisplayRole).toString());
             for(int m = m_mapper->first(); m < m_mapper->first() + columnCount; m++)
                 *barSet << m_model->data(m_model->index(i, m), Qt::DisplayRole).toDouble();
diff --git a/src/piechart/qpieseries.cpp b/src/piechart/qpieseries.cpp
index ebda719..076a2ae 100644
--- a/src/piechart/qpieseries.cpp
+++ b/src/piechart/qpieseries.cpp
@@ -716,12 +716,12 @@ void QPieSeriesPrivate::initializePieFromModel()
 {
     Q_Q(QPieSeries);
 
-    if (m_model == 0 || m_mapper == 0)
-        return;
-
     // clear current content
     q->clear();
 
+    if (m_model == 0 || m_mapper == 0)
+        return;
+
     // check if mappings are set
     if (m_mapper->mapValues() == -1 || m_mapper->mapLabels() == -1)
         return;
diff --git a/test/auto/qgroupedbarseries/tst_qgroupedbarseries.cpp b/test/auto/qgroupedbarseries/tst_qgroupedbarseries.cpp
index f84e85e..9757f9b 100644
--- a/test/auto/qgroupedbarseries/tst_qgroupedbarseries.cpp
+++ b/test/auto/qgroupedbarseries/tst_qgroupedbarseries.cpp
@@ -23,6 +23,8 @@
 #include <qbarset.h>
 #include <qchartview.h>
 #include <qchart.h>
+#include <QBarModelMapper>
+#include <QStandardItemModel>
 
 QTCOMMERCIALCHART_USE_NAMESPACE
 
@@ -47,6 +49,7 @@ private slots:
     void mouseclicked();
     void mousehovered_data();
     void mousehovered();
+    void model();
 
 private:
     QGroupedBarSeries* m_barseries;
@@ -335,6 +338,59 @@ void tst_QGroupedBarSeries::mousehovered()
     QVERIFY(seriesSpyArg.at(1).toBool() == false);
 }
 
+void tst_QGroupedBarSeries::model()
+{
+    QGroupedBarSeries *series = new QGroupedBarSeries;
+    QChart *chart = new QChart;
+    chart->addSeries(series);
+    QChartView *chartView = new QChartView(chart);
+    chartView->show();
+
+    int rowCount = 12;
+    int columnCount = 5;
+    QStandardItemModel *stdModel = new QStandardItemModel(rowCount, columnCount);
+    series->setModel(stdModel);
+    QVERIFY2((series->model()) == stdModel, "Model should be stdModel");
+
+
+    for (int row = 0; row < rowCount; ++row) {
+        for (int column = 0; column < columnCount; column++) {
+            QStandardItem *item = new QStandardItem(row * column);
+            stdModel->setItem(row, column, item);
+        }
+    }
+
+    // data has been added to the model, but mapper is not set the number of slices should still be 0
+    QVERIFY2(series->barsetCount() == 0, "Mapper has not been set, so the number of slices should be 0");
+
+    // set the mapper
+    QBarModelMapper *mapper = new QBarModelMapper;
+    mapper->setMapCategories(0);
+    mapper->setMapBarBottom(1);
+    mapper->setMapBarTop(3);
+    series->setModelMapper(mapper); // this should cause the Pie to get initialized from the model, since there is now both the model and the mapper defined
+    QCOMPARE(series->barsetCount(), 3);
+
+    // set the mappings to be outside of the model
+    mapper->setMapBarBottom(6);
+    mapper->setMapBarTop(7);
+    QCOMPARE(series->barsetCount(), 0); // Mappings are invalid, so the number of slices should be 0
+
+    // set back to correct ones
+    mapper->setMapBarBottom(1);
+    mapper->setMapBarTop(3);
+    QCOMPARE(series->barsetCount(), 3);
+
+    // reset the mappings
+    mapper->reset();
+    QCOMPARE(series->barsetCount(), 0); // Mappings have been reset and are invalid, so the number of slices should be 0
+
+    // unset the model and the mapper
+    series->setModel(0);
+    series->setModelMapper(0);
+    QVERIFY(series->model() == 0); // Model should be unset
+    QVERIFY(series->modelMapper() == 0); // Model mapper should be unset
+}
 
 /*
 bool setModel(QAbstractItemModel *model);
diff --git a/test/auto/qpieseries/tst_qpieseries.cpp b/test/auto/qpieseries/tst_qpieseries.cpp
index 1aa5e0e..6a03511 100644
--- a/test/auto/qpieseries/tst_qpieseries.cpp
+++ b/test/auto/qpieseries/tst_qpieseries.cpp
@@ -425,9 +425,9 @@ void tst_qpieseries::modelUpdate()
 {
     int rowCount = 12;
     int columnCount = 7;
-    QStandardItemModel *stdModel = new QStandardItemModel(0, 3);
+    QStandardItemModel *stdModel = new QStandardItemModel(rowCount, columnCount);
     for (int row = 0; row < rowCount; ++row) {
-        for (int column = 0; column < 2; column++) {
+        for (int column = 0; column < columnCount; column++) {
             QStandardItem *item = new QStandardItem(row * column);
             stdModel->setItem(row, column, item);
         }