Correct QStandardItemModel::setItemData to follow QAbstractItemModel

QStandardItemModel::setItemData replaces the content of an item data
with the new values rather than updating/inserting which is
the behavior for QAbstractItemModel. This patch aims to unify the
behavior.

[ChangeLog][QtWidgets][QStandardItemModel] Fixed setItemData()
incorrectly deleting unmodified data. That behavior is not
following QAbstractItemModel's documented behavior which is
no modification of data not provided in parameter.

Task-number: QTBUG-45114
Task-number: QTBUG-10872
Change-Id: I2be40cee372b68d9f71c976548ecda6dc3011241
Reviewed-by: David Faure <david.faure@kdab.com>

1 files changed, 11 insertions, 0 deletions

diff --git a/src/gui/itemmodels/qstandarditemmodel_p.h b/src/gui/itemmodels/qstandarditemmodel_p.h
index 516cce8613..caee3ea34c 100644
--- a/src/gui/itemmodels/qstandarditemmodel_p.h
+++ b/src/gui/itemmodels/qstandarditemmodel_p.h
@@ -61,6 +61,7 @@
 #include <QtCore/qstack.h>
 #include <QtCore/qvariant.h>
 #include <QtCore/qvector.h>
+#include <QtCore/qdebug.h>
 
 QT_BEGIN_NAMESPACE
 
@@ -69,6 +70,7 @@ class QStandardItemData
 public:
     inline QStandardItemData() : role(-1) {}
     inline QStandardItemData(int r, const QVariant &v) : role(r), value(v) {}
+    inline QStandardItemData(const std::pair<const int&, const QVariant&> &p) : role(p.first), value(p.second) {}
     int role;
     QVariant value;
     inline bool operator==(const QStandardItemData &other) const { return role == other.role && value == other.value; }
@@ -91,6 +93,15 @@ inline QDataStream &operator<<(QDataStream &out, const QStandardItemData &data)
     return out;
 }
 
+inline QDebug &operator<<(QDebug &debug, const QStandardItemData &data)
+{
+    QDebugStateSaver saver(debug);
+    debug.nospace() << data.role
+                    << " "
+                    << data.value;
+    return debug.space();
+}
+
 #endif // QT_NO_DATASTREAM
 
 class QStandardItemPrivate