1 files changed, 58 insertions, 37 deletions

diff --git a/src/corelib/itemmodels/qabstractproxymodel.cpp b/src/corelib/itemmodels/qabstractproxymodel.cpp
index 99324a0cd5..abdeefb4da 100644
--- a/src/corelib/itemmodels/qabstractproxymodel.cpp
+++ b/src/corelib/itemmodels/qabstractproxymodel.cpp
@@ -55,6 +55,41 @@ void QAbstractProxyModelPrivate::_q_sourceModelDestroyed()
     model = QAbstractItemModelPrivate::staticEmptyModel();
 }
 
+void QAbstractProxyModelPrivate::emitHeaderDataChanged()
+{
+    Q_Q(QAbstractProxyModel);
+
+    if (updateHorizontalHeader) {
+        if (auto columnCount = q->columnCount(); columnCount > 0)
+            emit q->headerDataChanged(Qt::Horizontal, 0, columnCount - 1);
+    }
+
+    if (updateVerticalHeader) {
+        if (auto rowCount = q->rowCount(); rowCount > 0)
+            emit q->headerDataChanged(Qt::Vertical, 0, rowCount - 1);
+    }
+
+    updateHorizontalHeader = false;
+    updateVerticalHeader = false;
+}
+
+void QAbstractProxyModelPrivate::scheduleHeaderUpdate(Qt::Orientation orientation)
+{
+    const bool isUpdateScheduled = updateHorizontalHeader || updateVerticalHeader;
+
+    if (orientation == Qt::Horizontal && !updateHorizontalHeader)
+        updateHorizontalHeader = true;
+    else if (orientation == Qt::Vertical && !updateVerticalHeader)
+        updateVerticalHeader = true;
+    else
+        return;
+
+    if (!isUpdateScheduled) {
+        Q_Q(QAbstractProxyModel);
+        QMetaObject::invokeMethod(q, [this]() { emitHeaderDataChanged(); }, Qt::QueuedConnection);
+    }
+}
+
 void QAbstractProxyModelPrivate::_q_sourceModelRowsAboutToBeInserted(const QModelIndex &parent, int, int)
 {
     if (parent.isValid())
@@ -66,25 +101,16 @@ void QAbstractProxyModelPrivate::_q_sourceModelRowsInserted(const QModelIndex &p
 {
     if (parent.isValid())
         return;
-    if (sourceHadZeroRows) {
-        Q_Q(QAbstractProxyModel);
-        const int columnCount = q->columnCount();
-        if (columnCount > 0)
-            emit q->headerDataChanged(Qt::Horizontal, 0, columnCount - 1);
-    }
+    if (sourceHadZeroRows)
+        scheduleHeaderUpdate(Qt::Horizontal);
 }
 
-
 void QAbstractProxyModelPrivate::_q_sourceModelRowsRemoved(const QModelIndex &parent, int, int)
 {
     if (parent.isValid())
         return;
-    if (model->rowCount() == 0) {
-        Q_Q(QAbstractProxyModel);
-        const int columnCount = q->columnCount();
-        if (columnCount > 0)
-            emit q->headerDataChanged(Qt::Horizontal, 0, columnCount - 1);
-    }
+    if (model->rowCount() == 0)
+        scheduleHeaderUpdate(Qt::Horizontal);
 }
 
 void QAbstractProxyModelPrivate::_q_sourceModelColumnsAboutToBeInserted(const QModelIndex &parent, int, int)
@@ -98,24 +124,16 @@ void QAbstractProxyModelPrivate::_q_sourceModelColumnsInserted(const QModelIndex
 {
     if (parent.isValid())
         return;
-    if (sourceHadZeroColumns) {
-        Q_Q(QAbstractProxyModel);
-        const int rowCount = q->rowCount();
-        if (rowCount > 0)
-            emit q->headerDataChanged(Qt::Vertical, 0, rowCount - 1);
-    }
+    if (sourceHadZeroColumns)
+        scheduleHeaderUpdate(Qt::Vertical);
 }
 
 void QAbstractProxyModelPrivate::_q_sourceModelColumnsRemoved(const QModelIndex &parent, int, int)
 {
     if (parent.isValid())
         return;
-    if (model->columnCount() == 0) {
-        Q_Q(QAbstractProxyModel);
-        const int rowCount = q->rowCount();
-        if (rowCount > 0)
-            emit q->headerDataChanged(Qt::Vertical, 0, rowCount - 1);
-    }
+    if (model->columnCount() == 0)
+        scheduleHeaderUpdate(Qt::Vertical);
 }
 
 /*!
@@ -159,31 +177,34 @@ void QAbstractProxyModel::setSourceModel(QAbstractItemModel *sourceModel)
     d->model.removeBindingUnlessInWrapper();
     // Special case to handle nullptr models. Otherwise we will have unwanted
     // notifications.
-    if (!sourceModel && d->model == QAbstractItemModelPrivate::staticEmptyModel())
+    const QAbstractItemModel *currentModel = d->model.valueBypassingBindings();
+    if (!sourceModel && currentModel == QAbstractItemModelPrivate::staticEmptyModel())
         return;
     static const struct {
         const char *signalName;
         const char *slotName;
     } connectionTable[] = {
+        // clang-format off
         { SIGNAL(destroyed()), SLOT(_q_sourceModelDestroyed()) },
-        { SIGNAL(rowsAboutToBeInserted(QModelIndex, int, int)), SLOT(_q_sourceModelRowsAboutToBeInserted(QModelIndex, int, int)) },
-        { SIGNAL(rowsInserted(QModelIndex, int, int)), SLOT(_q_sourceModelRowsInserted(QModelIndex, int, int)) },
-        { SIGNAL(rowsRemoved(QModelIndex, int, int)), SLOT(_q_sourceModelRowsRemoved(QModelIndex, int, int)) },
-        { SIGNAL(columnsAboutToBeInserted(QModelIndex, int, int)), SLOT(_q_sourceModelColumnsAboutToBeInserted(QModelIndex, int, int)) },
-        { SIGNAL(columnsInserted(QModelIndex, int, int)), SLOT(_q_sourceModelColumnsInserted(QModelIndex, int, int)) },
-        { SIGNAL(columnsRemoved(QModelIndex, int, int)), SLOT(_q_sourceModelColumnsRemoved(QModelIndex, int, int)) }
+        { SIGNAL(rowsAboutToBeInserted(QModelIndex,int,int)), SLOT(_q_sourceModelRowsAboutToBeInserted(QModelIndex,int,int)) },
+        { SIGNAL(rowsInserted(QModelIndex,int,int)), SLOT(_q_sourceModelRowsInserted(QModelIndex,int,int)) },
+        { SIGNAL(rowsRemoved(QModelIndex,int,int)), SLOT(_q_sourceModelRowsRemoved(QModelIndex,int,int)) },
+        { SIGNAL(columnsAboutToBeInserted(QModelIndex,int,int)), SLOT(_q_sourceModelColumnsAboutToBeInserted(QModelIndex,int,int)) },
+        { SIGNAL(columnsInserted(QModelIndex,int,int)), SLOT(_q_sourceModelColumnsInserted(QModelIndex,int,int)) },
+        { SIGNAL(columnsRemoved(QModelIndex,int,int)), SLOT(_q_sourceModelColumnsRemoved(QModelIndex,int,int)) }
+        // clang-format on
     };
 
-    if (sourceModel != d->model) {
-        if (d->model) {
+    if (sourceModel != currentModel) {
+        if (currentModel) {
             for (const auto &c : connectionTable)
-                disconnect(d->model, c.signalName, this, c.slotName);
+                disconnect(currentModel, c.signalName, this, c.slotName);
         }
 
         if (sourceModel) {
             d->model.setValueBypassingBindings(sourceModel);
             for (const auto &c : connectionTable)
-                connect(d->model, c.signalName, this, c.slotName);
+                connect(sourceModel, c.signalName, this, c.slotName);
         } else {
             d->model.setValueBypassingBindings(QAbstractItemModelPrivate::staticEmptyModel());
         }
@@ -443,7 +464,7 @@ QMimeData* QAbstractProxyModel::mimeData(const QModelIndexList &indexes) const
 {
     Q_D(const QAbstractProxyModel);
     QModelIndexList list;
-    list.reserve(indexes.count());
+    list.reserve(indexes.size());
     for (const QModelIndex &index : indexes)
         list << mapToSource(index);
     return d->model->mimeData(list);