5 files changed, 19 insertions, 6 deletions
diff --git a/src/widgets/widgets/qabstractscrollarea.cpp b/src/widgets/widgets/qabstractscrollarea.cpp
index 5e45c66f3b..65d06eafc5 100644
--- a/src/widgets/widgets/qabstractscrollarea.cpp
+++ b/src/widgets/widgets/qabstractscrollarea.cpp
@@ -210,10 +210,12 @@ QWidgetList QAbstractScrollAreaScrollBarContainer::widgets(LogicalPosition posit
     QWidgetList list;
     const int scrollBarIndex = scrollBarLayoutIndex();
     if (position == LogicalLeft) {
+        list.reserve(scrollBarIndex);
         for (int i = 0; i < scrollBarIndex; ++i)
             list.append(layout->itemAt(i)->widget());
     } else if (position == LogicalRight) {
         const int layoutItemCount = layout->count();
+        list.reserve(layoutItemCount - (scrollBarIndex + 1));
         for (int i = scrollBarIndex + 1; i < layoutItemCount; ++i)
             list.append(layout->itemAt(i)->widget());
     }
diff --git a/src/widgets/widgets/qcombobox.cpp b/src/widgets/widgets/qcombobox.cpp
index ef80e359df..d4deea652b 100644
--- a/src/widgets/widgets/qcombobox.cpp
+++ b/src/widgets/widgets/qcombobox.cpp
@@ -2263,6 +2263,7 @@ void QComboBox::insertItems(int index, const QStringList &list)
     // construct a QStandardItem, reducing the number of expensive signals from the model
     if (QStandardItemModel *m = qobject_cast<QStandardItemModel*>(d->model)) {
         QList<QStandardItem *> items;
+        items.reserve(insertCount);
         QStandardItem *hiddenRoot = m->invisibleRootItem();
         for (int i = 0; i < insertCount; ++i)
             items.append(new QStandardItem(list.at(i)));
diff --git a/src/widgets/widgets/qdockarealayout.cpp b/src/widgets/widgets/qdockarealayout.cpp
index 8054c8aa46..c61984a457 100644
--- a/src/widgets/widgets/qdockarealayout.cpp
+++ b/src/widgets/widgets/qdockarealayout.cpp
@@ -2211,8 +2211,10 @@ QSet<QTabBar*> QDockAreaLayoutInfo::usedTabBars() const
 QSet<QWidget*> QDockAreaLayoutInfo::usedSeparatorWidgets() const
 {
     QSet<QWidget*> result;
+    const int numSeparatorWidgets = separatorWidgets.count();
+    result.reserve(numSeparatorWidgets);
 
-    for (int i = 0; i < separatorWidgets.count(); ++i)
+    for (int i = 0; i < numSeparatorWidgets; ++i)
         result << separatorWidgets.at(i);
 
     for (int i = 0; i < item_list.count(); ++i) {
diff --git a/src/widgets/widgets/qsplitter.cpp b/src/widgets/widgets/qsplitter.cpp
index 38773a4fbf..c2081c15f8 100644
--- a/src/widgets/widgets/qsplitter.cpp
+++ b/src/widgets/widgets/qsplitter.cpp
@@ -1502,8 +1502,11 @@ QList<int> QSplitter::sizes() const
     Q_D(const QSplitter);
     ensurePolished();
 
+    const int numSizes = d->list.size();
     QList<int> list;
-    for (int i = 0; i < d->list.size(); ++i) {
+    list.reserve(numSizes);
+
+    for (int i = 0; i < numSizes; ++i) {
         QSplitterLayoutStruct *s = d->list.at(i);
         list.append(d->pick(s->rect.size()));
     }
@@ -1598,8 +1601,10 @@ QByteArray QSplitter::saveState() const
 
     stream << qint32(SplitterMagic);
     stream << qint32(version);
+    const int numSizes = d->list.size();
     QList<int> list;
-    for (int i = 0; i < d->list.size(); ++i) {
+    list.reserve(numSizes);
+    for (int i = 0; i < numSizes; ++i) {
         QSplitterLayoutStruct *s = d->list.at(i);
         list.append(s->sizer);
     }
diff --git a/src/widgets/widgets/qwidgettextcontrol.cpp b/src/widgets/widgets/qwidgettextcontrol.cpp
index 22d199fc74..bebdd16736 100644
--- a/src/widgets/widgets/qwidgettextcontrol.cpp
+++ b/src/widgets/widgets/qwidgettextcontrol.cpp
@@ -2439,10 +2439,13 @@ QList<QTextEdit::ExtraSelection> QWidgetTextControl::extraSelections() const
 {
     Q_D(const QWidgetTextControl);
     QList<QTextEdit::ExtraSelection> selections;
-    for (int i = 0; i < d->extraSelections.count(); ++i) {
+    const int numExtraSelections = d->extraSelections.count();
+    selections.reserve(numExtraSelections);
+    for (int i = 0; i < numExtraSelections; ++i) {
         QTextEdit::ExtraSelection sel;
-        sel.cursor = d->extraSelections.at(i).cursor;
-        sel.format = d->extraSelections.at(i).format;
+        const QAbstractTextDocumentLayout::Selection &sel2 = d->extraSelections.at(i);
+        sel.cursor = sel2.cursor;
+        sel.format = sel2.format;
         selections.append(sel);
     }
     return selections;