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>

1 files changed, 6 insertions, 2 deletions

diff --git a/tests/auto/qquickheaderview/tst_qquickheaderview.cpp b/tests/auto/qquickheaderview/tst_qquickheaderview.cpp
index d8d71183..14e0bb79 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)