4 files changed, 44 insertions, 0 deletions
diff --git a/src/quicktemplates2/qquickcontrol.cpp b/src/quicktemplates2/qquickcontrol.cpp
index ac1303a2..23ebf345 100644
--- a/src/quicktemplates2/qquickcontrol.cpp
+++ b/src/quicktemplates2/qquickcontrol.cpp
@@ -853,6 +853,13 @@ void QQuickControlPrivate::executeBackground(bool complete)
         quickCompleteDeferred(q, backgroundName(), background);
 }
 
+/*
+    \internal
+
+    Hides an item that was replaced by a newer one, rather than
+    deleting it, as the item is typically created in QML and hence
+    we don't own it.
+*/
 void QQuickControlPrivate::hideOldItem(QQuickItem *item)
 {
     if (!item)
@@ -871,6 +878,29 @@ void QQuickControlPrivate::hideOldItem(QQuickItem *item)
 #endif
 }
 
+/*
+    \internal
+
+    Named "unhide" because it's used for cases where an item
+    that was previously hidden by \l hideOldItem() wants to be
+    shown by a control again, such as a ScrollBar in ScrollView.
+*/
+void QQuickControlPrivate::unhideOldItem(QQuickControl *control, QQuickItem *item)
+{
+    Q_ASSERT(item);
+    qCDebug(lcItemManagement) << "unhiding old item" << item;
+
+    item->setVisible(true);
+    item->setParentItem(control);
+
+#if QT_CONFIG(accessibility)
+    // Add the item back in to the accessibility tree.
+    QQuickAccessibleAttached *accessible = accessibleAttached(item);
+    if (accessible)
+        accessible->setIgnored(false);
+#endif
+}
+
 void QQuickControlPrivate::updateBaselineOffset()
 {
     Q_Q(QQuickControl);
diff --git a/src/quicktemplates2/qquickcontrol_p_p.h b/src/quicktemplates2/qquickcontrol_p_p.h
index aca6d03f..a923aa18 100644
--- a/src/quicktemplates2/qquickcontrol_p_p.h
+++ b/src/quicktemplates2/qquickcontrol_p_p.h
@@ -173,6 +173,7 @@ public:
     virtual void executeBackground(bool complete = false);
 
     static void hideOldItem(QQuickItem *item);
+    static void unhideOldItem(QQuickControl *control, QQuickItem *item);
 
     void updateBaselineOffset();
 
diff --git a/src/quicktemplates2/qquickscrollbar.cpp b/src/quicktemplates2/qquickscrollbar.cpp
index c9016cc9..ec647407 100644
--- a/src/quicktemplates2/qquickscrollbar.cpp
+++ b/src/quicktemplates2/qquickscrollbar.cpp
@@ -797,6 +797,14 @@ void QQuickScrollBarAttachedPrivate::initHorizontal()
     if (parent && parent == flickable->parentItem())
         horizontal->stackAfter(flickable);
 
+    // If a scroll bar was previously hidden (due to e.g. setting a new contentItem
+    // on a ScrollView), we need to make sure that we un-hide it.
+    // We don't bother checking if the item is actually the old one, because
+    // if it's not, all of the things the function does (setting parent, visibility, etc.)
+    // should be no-ops anyway.
+    if (auto control = qobject_cast<QQuickControl*>(q_func()->parent()))
+        QQuickControlPrivate::unhideOldItem(control, horizontal);
+
     layoutHorizontal();
     horizontal->setSize(area->property("widthRatio").toReal());
     horizontal->setPosition(area->property("xPosition").toReal());
@@ -818,6 +826,9 @@ void QQuickScrollBarAttachedPrivate::initVertical()
     if (parent && parent == flickable->parentItem())
         vertical->stackAfter(flickable);
 
+    if (auto control = qobject_cast<QQuickControl*>(q_func()->parent()))
+        QQuickControlPrivate::unhideOldItem(control, vertical);
+
     layoutVertical();
     vertical->setSize(area->property("heightRatio").toReal());
     vertical->setPosition(area->property("yPosition").toReal());
diff --git a/src/quicktemplates2/qquickscrollbar_p_p.h b/src/quicktemplates2/qquickscrollbar_p_p.h
index 6841ec73..bbb5f6c1 100644
--- a/src/quicktemplates2/qquickscrollbar_p_p.h
+++ b/src/quicktemplates2/qquickscrollbar_p_p.h
@@ -107,6 +107,8 @@ public:
 
 class QQuickScrollBarAttachedPrivate : public QObjectPrivate, public QQuickItemChangeListener
 {
+    Q_DECLARE_PUBLIC(QQuickScrollBar)
+
 public:
     static QQuickScrollBarAttachedPrivate *get(QQuickScrollBarAttached *attached)
     {