2 files changed, 9 insertions, 1 deletions
diff --git a/src/gui/graphicsview/qgraphicslayoutitem.cpp b/src/gui/graphicsview/qgraphicslayoutitem.cpp
index 3707591..634f68c 100644
--- a/src/gui/graphicsview/qgraphicslayoutitem.cpp
+++ b/src/gui/graphicsview/qgraphicslayoutitem.cpp
@@ -234,7 +234,7 @@ void QGraphicsLayoutItemPrivate::setSize(Qt::SizeHint which, const QSizeF &size)
     if (userSizeHints) {
         if (size == userSizeHints[which])
             return;
-    } else if (!size.isValid()) {
+    } else if (size.width() < 0 && size.height() < 0) {
         return;
     }
 
diff --git a/tests/auto/qgraphicslayoutitem/tst_qgraphicslayoutitem.cpp b/tests/auto/qgraphicslayoutitem/tst_qgraphicslayoutitem.cpp
index 879e12b..dbffa6e 100644
--- a/tests/auto/qgraphicslayoutitem/tst_qgraphicslayoutitem.cpp
+++ b/tests/auto/qgraphicslayoutitem/tst_qgraphicslayoutitem.cpp
@@ -75,6 +75,7 @@ private slots:
     void setPreferredSize_data();
     void setPreferredSize();
     void setSizePolicy_data();
+    void setPreferredSize2();
     void setSizePolicy();
 };
 
@@ -343,6 +344,13 @@ void tst_QGraphicsLayoutItem::setPreferredSize()
     }
 }
 
+void tst_QGraphicsLayoutItem::setPreferredSize2()
+{
+    SubQGraphicsLayoutItem layoutItem;
+    layoutItem.setPreferredSize(QSizeF(30, -1));
+    QCOMPARE(layoutItem.preferredWidth(), qreal(30));
+}
+
 void tst_QGraphicsLayoutItem::setSizePolicy_data()
 {
     QTest::addColumn<QSizePolicy>("policy");