QComboBox: deprecate signal currentIndexChanged(const QString &)

QComboBox has two overloaded signals currentIndexChanged(). This results
in a need to use QOverload<>::of or similar when using the new
signal/slot syntax.
Since there is already a signal 'currentTextChanged()' which is
emitted too, deprecate 'currentIndexChanged(const QString &)'.

Change-Id: Iadac8930de1721b042fa1daea097c8ab5378738e
Reviewed-by: Samuel Gaist <samuel.gaist@idiap.ch>
Reviewed-by: Richard Moe Gustavsen <richard.gustavsen@qt.io>

src/widgets/widgets/qcombobox.cpp

@@ -895,14 +895,21 @@ QStyleOptionComboBox QComboBoxPrivateContainer::comboStyleOption() const
     currentIndex was reset.
 */
 
+#if QT_DEPRECATED_SINCE(5, 13)
 /*!
     \fn void QComboBox::currentIndexChanged(const QString &text)
     \since 4.1
 
+    \obsolete
+
+    Use currentTextChanged(const QString &) or currentIndexChanged(int)
+    instead.
+
     This signal is sent whenever the currentIndex in the combobox
     changes either through user interaction or programmatically.  The
     item's \a text is passed.
 */
+#endif
 
 /*!
     \fn void QComboBox::currentTextChanged(const QString &text)
@@ -1375,7 +1382,9 @@ void QComboBoxPrivate::_q_emitCurrentIndexChanged(const QModelIndex &index)
     Q_Q(QComboBox);
     const QString text = itemText(index);
     emit q->currentIndexChanged(index.row());
+#if QT_DEPRECATED_SINCE(5, 13)
     emit q->currentIndexChanged(text);
+#endif
     // signal lineEdit.textChanged already connected to signal currentTextChanged, so don't emit double here
     if (!lineEdit)
         emit q->currentTextChanged(text);

src/widgets/widgets/qcombobox.h

@@ -224,7 +224,10 @@ Q_SIGNALS:
     void highlighted(int index);
     void highlighted(const QString &);
     void currentIndexChanged(int index);
+#if QT_DEPRECATED_SINCE(5, 13)
+    QT_DEPRECATED_X("Use currentTextChanged() instead")
     void currentIndexChanged(const QString &);
+#endif
     void currentTextChanged(const QString &);
 
 protected: