Fix QStandardItem::setChild crash when passing a null pointer

Passing a null pointer as a parameter to the setChild function no
longer crashes when calling the
QStandardItemModelPrivate::itemChanged signal. The child is removed
from the model.
The patch also fixes the behavior of deleting a item. A
dataChanged signal is emitted.

Change-Id: I027e8b0d84fe33c5fca056df870f0e60a020824b
Reviewed-by: David Faure <david.faure@kdab.com>

1 files changed, 13 insertions, 2 deletions

diff --git a/src/gui/itemmodels/qstandarditemmodel.cpp b/src/gui/itemmodels/qstandarditemmodel.cpp
index 1d6e2924b1..07e372b1ae 100644
--- a/src/gui/itemmodels/qstandarditemmodel.cpp
+++ b/src/gui/itemmodels/qstandarditemmodel.cpp
@@ -148,8 +148,14 @@ void QStandardItemPrivate::setChild(int row, int column, QStandardItem *item,
     if (model && emitChanged)
         emit model->layoutChanged();
 
-    if (emitChanged && model)
-        model->d_func()->itemChanged(item);
+    if (emitChanged && model) {
+        if (item) {
+            model->d_func()->itemChanged(item);
+        } else {
+            const QModelIndex idx = model->index(row, column, q->index());
+            emit model->dataChanged(idx, idx);
+        }
+    }
 }
 
 
@@ -174,7 +180,9 @@ void QStandardItemPrivate::childDeleted(QStandardItem *child)
 {
     int index = childIndex(child);
     Q_ASSERT(index != -1);
+    const auto modelIndex = child->index();
     children.replace(index, 0);
+    emit model->dataChanged(modelIndex, modelIndex);
 }
 
 /*!
@@ -476,6 +484,7 @@ bool QStandardItemPrivate::insertColumns(int column, int count, const QList<QSta
 void QStandardItemModelPrivate::itemChanged(QStandardItem *item)
 {
     Q_Q(QStandardItemModel);
+    Q_ASSERT(item);
     if (item->d_func()->parent == 0) {
         // Header item
         int idx = columnHeaderItems.indexOf(item);
@@ -1721,6 +1730,8 @@ bool QStandardItem::hasChildren() const
     item) takes ownership of \a item. If necessary, the row count and column
     count are increased to fit the item.
 
+    \note Passing a null pointer as \a item removes the item.
+
     \sa child()
 */
 void QStandardItem::setChild(int row, int column, QStandardItem *item)