Fix QQuickHeaderView models to pass model tester

Following 72e0d699cec09458ca9325035d477d4899e8e47b in qtbase, the model
tester exercises additional code paths to verify correct row/columnCount
implementations for flat models.

This revealed a few bugs in the models used in QQuickHeaderView and the
unit test:

* neither QHeaderDataProxyModel nor the test models handled a valid
parent index for calls to row/columnCount
* QHeaderDataProxyModel::sibling passed the index on as parent

Change-Id: I612e18030d837275614d61ce8987c93fff7f20a9
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
(cherry picked from commit bdc14837191dc81452fa7fbba20ba0a29e5fbebd)
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>

2 files changed, 14 insertions, 5 deletions

diff --git a/src/quicktemplates2/qquickheaderview.cpp b/src/quicktemplates2/qquickheaderview.cpp
index 85291bcb..d99c09eb 100644
--- a/src/quicktemplates2/qquickheaderview.cpp
+++ b/src/quicktemplates2/qquickheaderview.cpp
@@ -364,18 +364,22 @@ QModelIndex QHeaderDataProxyModel::parent(const QModelIndex &child) const
     return QModelIndex();
 }
 
-QModelIndex QHeaderDataProxyModel::sibling(int row, int column, const QModelIndex &idx) const
+QModelIndex QHeaderDataProxyModel::sibling(int row, int column, const QModelIndex &) const
 {
-    return index(row, column, idx);
+    return index(row, column);
 }
 
 int QHeaderDataProxyModel::rowCount(const QModelIndex &parent) const
 {
+    if (parent.isValid())
+        return 0;
     return m_model.isNull() ? -1 : (m_orientation == Qt::Horizontal ? 1 : m_model->rowCount(parent));
 }
 
 int QHeaderDataProxyModel::columnCount(const QModelIndex &parent) const
 {
+    if (parent.isValid())
+        return 0;
     return m_model.isNull() ? -1 : (m_orientation == Qt::Vertical ? 1 : m_model->columnCount(parent));
 }
 
@@ -401,7 +405,8 @@ bool QHeaderDataProxyModel::setData(const QModelIndex &index, const QVariant &va
 
 bool QHeaderDataProxyModel::hasChildren(const QModelIndex &parent) const
 {
-    Q_UNUSED(parent)
+    if (!parent.isValid())
+        return rowCount(parent) > 0 && columnCount(parent) > 0;
     return false;
 }
 
diff --git a/tests/auto/qquickheaderview/tst_qquickheaderview.cpp b/tests/auto/qquickheaderview/tst_qquickheaderview.cpp
index 611e39cb..f335aa86 100644
--- a/tests/auto/qquickheaderview/tst_qquickheaderview.cpp
+++ b/tests/auto/qquickheaderview/tst_qquickheaderview.cpp
@@ -58,8 +58,10 @@ public:
     {
     }
 
-    int rowCount(const QModelIndex & = QModelIndex()) const override
+    int rowCount(const QModelIndex &index = QModelIndex()) const override
     {
+        if (index.isValid())
+            return 0;
         return m_rows;
     }
     virtual void setRowCount(int count)
@@ -70,8 +72,10 @@ public:
         endResetModel();
     }
 
-    int columnCount(const QModelIndex & = QModelIndex()) const override
+    int columnCount(const QModelIndex &index = QModelIndex()) const override
     {
+        if (index.isValid())
+            return 0;
         return m_cols;
     }
     virtual void setColumnCount(int count)