2 files changed, 12 insertions, 11 deletions
diff --git a/src/widgets/widgets/qwidgetlinecontrol.cpp b/src/widgets/widgets/qwidgetlinecontrol.cpp
index 86903dc0c3..e01c8f536e 100644
--- a/src/widgets/widgets/qwidgetlinecontrol.cpp
+++ b/src/widgets/widgets/qwidgetlinecontrol.cpp
@@ -717,7 +717,7 @@ bool QWidgetLineControl::finishChange(int validateFromState, bool update, bool e
             if (m_transactions.count())
                 return false;
             internalUndo(validateFromState);
-            m_history.resize(m_undoState);
+            m_history.erase(m_history.begin() + m_undoState, m_history.end());
             if (m_modifiedState > m_undoState)
                 m_modifiedState = -1;
             m_validInput = true;
@@ -796,14 +796,14 @@ void QWidgetLineControl::internalSetText(const QString &txt, int pos, bool edite
 */
 void QWidgetLineControl::addCommand(const Command &cmd)
 {
-    if (m_separator && m_undoState && m_history[m_undoState - 1].type != Separator) {
-        m_history.resize(m_undoState + 2);
-        m_history[m_undoState++] = Command(Separator, m_cursor, 0, m_selstart, m_selend);
-    } else {
-        m_history.resize(m_undoState + 1);
-    }
+    m_history.erase(m_history.begin() + m_undoState, m_history.end());
+
+    if (m_separator && m_undoState && m_history[m_undoState - 1].type != Separator)
+        m_history.push_back(Command(Separator, m_cursor, 0, m_selstart, m_selend));
+
     m_separator = false;
-    m_history[m_undoState++] = cmd;
+    m_history.push_back(cmd);
+    m_undoState = int(m_history.size());
 }
 
 /*!
@@ -1957,7 +1957,7 @@ bool QWidgetLineControl::isRedoAvailable() const
     // Same as with undo. Disabled for password modes.
     return !m_readOnly
             && m_echoMode == QLineEdit::Normal
-            && m_undoState < m_history.size();
+            && m_undoState < int(m_history.size());
 }
 
 QT_END_NAMESPACE
diff --git a/src/widgets/widgets/qwidgetlinecontrol_p.h b/src/widgets/widgets/qwidgetlinecontrol_p.h
index 34d19d1e77..5e52e29a51 100644
--- a/src/widgets/widgets/qwidgetlinecontrol_p.h
+++ b/src/widgets/widgets/qwidgetlinecontrol_p.h
@@ -67,6 +67,8 @@
 
 #include "qplatformdefs.h"
 
+#include <vector>
+
 #ifdef DrawText
 #  undef DrawText
 #endif
@@ -469,7 +471,6 @@ private:
     // undo/redo handling
     enum CommandType { Separator, Insert, Remove, Delete, RemoveSelection, DeleteSelection, SetSelection };
     struct Command {
-        inline Command() {}
         inline Command(CommandType t, int p, QChar c, int ss, int se) : type(t),uc(c),pos(p),selStart(ss),selEnd(se) {}
         uint type : 4;
         QChar uc;
@@ -477,7 +478,7 @@ private:
     };
     int m_modifiedState;
     int m_undoState;
-    QVector<Command> m_history;
+    std::vector<Command> m_history;
     void addCommand(const Command& cmd);
 
     inline void separate() { m_separator = true; }