From c27d2a57a441f9a1ce760e71635bd4c96882249d Mon Sep 17 00:00:00 2001
From: Luca Beldi <v.ronin@yahoo.it>
Date: Tue, 19 Oct 2021 10:34:33 +0100
Subject: [PATCH] Make QAbstractProxyModel itemData() behave like data()

QAbstractProxyModel::itemData/setItemData should behave
just like data()/setData() instead of calling the
QAbstractItemModel implementation.
Before this change the QAbstractProxyModel implementation
calls its the QAbstractItemModel implementation,
which ends up calling data()/setData() in a loop
bypassing the convenience of itemData/setItemData.

[ChangeLog][QtCore][QAbstractProxyModel] The itemData()
and setItemData() functions will now call the respective
implementations in the source model (after mapping the
index to a source index), matching what data() and
setData() already did.
Before, the proxy model simply called the default
implementations of itemData()/setItemData() in its own
base class (QAbstractItemModel).

Change-Id: I9e680d355f44fa130660dd7e1c8ac37484c1566e
Reviewed-by: David Faure <david.faure@kdab.com>
---
 src/corelib/itemmodels/qabstractproxymodel.cpp        |  6 ++++--
 .../qidentityproxymodel/tst_qidentityproxymodel.cpp   | 11 ++++++++++-
 2 files changed, 14 insertions(+), 3 deletions(-)

diff --git a/src/corelib/itemmodels/qabstractproxymodel.cpp b/src/corelib/itemmodels/qabstractproxymodel.cpp
index 39fe44464cb..d8a93eee369 100644
--- a/src/corelib/itemmodels/qabstractproxymodel.cpp
+++ b/src/corelib/itemmodels/qabstractproxymodel.cpp
@@ -268,7 +268,8 @@ QVariant QAbstractProxyModel::headerData(int section, Qt::Orientation orientatio
  */
 QMap<int, QVariant> QAbstractProxyModel::itemData(const QModelIndex &proxyIndex) const
 {
-    return QAbstractItemModel::itemData(proxyIndex);
+    Q_D(const QAbstractProxyModel);
+    return d->model->itemData(mapToSource(proxyIndex));
 }
 
 /*!
@@ -294,7 +295,8 @@ bool QAbstractProxyModel::setData(const QModelIndex &index, const QVariant &valu
  */
 bool QAbstractProxyModel::setItemData(const QModelIndex &index, const QMap< int, QVariant >& roles)
 {
-    return QAbstractItemModel::setItemData(index, roles);
+    Q_D(QAbstractProxyModel);
+    return d->model->setItemData(mapToSource(index), roles);
 }
 
 /*!
diff --git a/tests/auto/corelib/itemmodels/qidentityproxymodel/tst_qidentityproxymodel.cpp b/tests/auto/corelib/itemmodels/qidentityproxymodel/tst_qidentityproxymodel.cpp
index 3f93938ed98..72f35647464 100644
--- a/tests/auto/corelib/itemmodels/qidentityproxymodel/tst_qidentityproxymodel.cpp
+++ b/tests/auto/corelib/itemmodels/qidentityproxymodel/tst_qidentityproxymodel.cpp
@@ -404,8 +404,17 @@ public:
         const QVariant result = QIdentityProxyModel::data(index, role);
         if (role != Qt::DisplayRole)
             return result;
-        return result.toString() + "_appended";
+        return result.toString() + QLatin1String("_appended");
     }
+    QMap<int, QVariant> itemData(const QModelIndex &index) const override
+    {
+        QMap<int, QVariant> result = QIdentityProxyModel::itemData(index);
+        auto displayIter = result.find(Qt::DisplayRole);
+        if (displayIter != result.end())
+            displayIter.value() = displayIter.value().toString() + QLatin1String("_appended");
+        return result;
+    }
+
 };
 
 void tst_QIdentityProxyModel::itemData()