Index: messagelist/autotests/quicksearchlinetest.cpp
===================================================================
--- messagelist/autotests/quicksearchlinetest.cpp
+++ messagelist/autotests/quicksearchlinetest.cpp
@@ -38,7 +38,6 @@
 {
     QuickSearchLine searchLine;
     QVERIFY(searchLine.searchEdit()->text().isEmpty());
-    QVERIFY(!searchLine.lockSearch()->isChecked());
     QWidget *widget = searchLine.findChild<QWidget *>(QStringLiteral("extraoptions"));
     QVERIFY(widget);
     QVERIFY(widget->isHidden());
@@ -166,7 +165,6 @@
     searchLine.show();
     searchLine.resetFilter();
     QCOMPARE(searchLine.status().count(), 0);
-    QCOMPARE(searchLine.lockSearch()->isChecked(), false);
     QCOMPARE(searchLine.tagFilterComboBox()->currentIndex(), -1);
     QuickSearchLine::SearchOptions options;
     options = QuickSearchLine::SearchEveryWhere;
Index: messagelist/src/core/widgetbase.cpp
===================================================================
--- messagelist/src/core/widgetbase.cpp
+++ messagelist/src/core/widgetbase.cpp
@@ -336,19 +336,6 @@
     d->setDefaultThemeForStorageModel(storageModel);
     d->setDefaultSortOrderForStorageModel(storageModel);
 
-    if (!d->quickSearchLine->lockSearch()->isChecked()) {
-        if (d->mSearchTimer) {
-            d->mSearchTimer->stop();
-            delete d->mSearchTimer;
-            d->mSearchTimer = Q_NULLPTR;
-        }
-
-        d->quickSearchLine->searchEdit()->clear();
-
-        if (d->mFilter) {
-            resetFilter();
-        }
-    }
     StorageModel *oldModel = d->mStorageModel;
 
     d->mStorageModel = storageModel;
Index: messagelist/src/core/widgets/quicksearchline.h
===================================================================
--- messagelist/src/core/widgets/quicksearchline.h
+++ messagelist/src/core/widgets/quicksearchline.h
@@ -61,7 +61,7 @@
     KComboBox *tagFilterComboBox() const;
     KLineEdit *searchEdit() const;
     QToolButton *openFullSearchButton() const;
-    QToolButton *lockSearch() const;
+
     void resetFilter();
     QList<Akonadi::MessageStatus> status() const;
 
@@ -81,7 +81,6 @@
 protected:
     bool eventFilter(QObject *object, QEvent *e) Q_DECL_OVERRIDE;
 private Q_SLOTS:
-    void slotLockSearchClicked(bool locked);
     void slotSearchOptionChanged();
     void slotSearchEditTextEdited(const QString &text);
     void slotClearButtonClicked();
@@ -95,7 +94,6 @@
     QList<QToolButton *> mListStatusButton;
     KLineEdit *mSearchEdit;
     KComboBox *mTagFilterCombo;
-    QToolButton *mLockSearch;
     QPushButton *mMoreOptions;
     QPushButton *mSearchEveryWhere;
     QPushButton *mSearchAgainstBody;
Index: messagelist/src/core/widgets/quicksearchline.cpp
===================================================================
--- messagelist/src/core/widgets/quicksearchline.cpp
+++ messagelist/src/core/widgets/quicksearchline.cpp
@@ -56,19 +56,6 @@
     w->setLayout(hbox);
     vbox->addWidget(w);
 
-    mLockSearch = new QToolButton(this);
-    mLockSearch->setCheckable(true);
-    mLockSearch->setText(i18nc("@action:button", "Lock search"));
-    mLockSearch->setFocusPolicy(Qt::StrongFocus);
-    mLockSearch->setWhatsThis(
-        i18nc("@info:whatsthis",
-              "Toggle this button if you want to keep your quick search "
-              "locked when moving to other folders or when narrowing the search "
-              "by message status."));
-    slotLockSearchClicked(false);
-    connect(mLockSearch, &QToolButton::toggled, this, &QuickSearchLine::slotLockSearchClicked);
-    hbox->addWidget(mLockSearch);
-
     mQuickSearchFilterWidget = new QWidget;
     mQuickSearchFilterWidget->setObjectName(QStringLiteral("quicksearchfilterwidget"));
     QHBoxLayout *quickSearchButtonLayout = new QHBoxLayout;
@@ -161,7 +148,6 @@
     installEventFilter(this);
     mMoreOptions->installEventFilter(this);
     mTagFilterCombo->installEventFilter(this);
-    mLockSearch->installEventFilter(this);
     mSearchEveryWhere->installEventFilter(this);
     mSearchAgainstBody->installEventFilter(this);
     mSearchAgainstSubject->installEventFilter(this);
@@ -286,22 +272,6 @@
     return mSearchEdit;
 }
 
-QToolButton *QuickSearchLine::lockSearch() const
-{
-    return mLockSearch;
-}
-
-void QuickSearchLine::slotLockSearchClicked(bool locked)
-{
-    if (locked) {
-        mLockSearch->setIcon(QIcon::fromTheme(QStringLiteral("object-locked")));
-        mLockSearch->setToolTip(i18nc("@info:tooltip",
-                                      "Prevent the quick search field from being cleared when changing folders"));
-    } else {
-        mLockSearch->setIcon(QIcon::fromTheme(QStringLiteral("object-unlocked")));
-        mLockSearch->setToolTip(i18nc("@info:tooltip", "Clear the quick search field when changing folders"));
-    }
-}
 
 void QuickSearchLine::resetFilter()
 {
@@ -311,7 +281,6 @@
     if (mTagFilterCombo->isVisible()) {
         mTagFilterCombo->setCurrentIndex(0);
     }
-    mLockSearch->setChecked(false);
     mSearchEveryWhere->setChecked(true);
     mSearchAgainstBody->setChecked(false);
     mSearchAgainstSubject->setChecked(false);
@@ -443,6 +412,5 @@
 {
     mSearchEdit->setVisible(show);
     mTagFilterCombo->setVisible(show && mTagFilterCombo->count());
-    mLockSearch->setVisible(show);
     mMoreOptions->setVisible(show);
 }