Do not dereference null pointer

Part of #12226

diff --git a/src/frontends/qt/TocWidget.cpp b/src/frontends/qt/TocWidget.cpp
index 8e32774d017dc15fd7d2f6c4b2d94a8e2570ebc2..957b3a64e03a8c782cb7269eaa5cb9ba9148ce1c 100644 (file)
--- a/src/frontends/qt/TocWidget.cpp
+++ b/src/frontends/qt/TocWidget.cpp
@@ -534,7 +534,7 @@ void TocWidget::filterContents()
        int size = indices.size();
        for (int i = 0; i < size; i++) {
                QModelIndex index = indices[i];
-               bool matches =
+               bool matches = filter_ &&
                        index.data().toString().contains(
                                filter_->text(), Qt::CaseInsensitive);
                TocItem const & item =