3 files changed, 56 insertions, 6 deletions

diff --git a/src/gui/graphicsview/qgraphicsanchorlayout_p.cpp b/src/gui/graphicsview/qgraphicsanchorlayout_p.cpp
index fb67278..b324469 100644
--- a/src/gui/graphicsview/qgraphicsanchorlayout_p.cpp
+++ b/src/gui/graphicsview/qgraphicsanchorlayout_p.cpp
@@ -1272,7 +1272,6 @@ void QGraphicsAnchorLayoutPrivate::createLayoutEdges()
     addAnchor_helper(layout, Qt::AnchorLeft, layout,
                      Qt::AnchorRight, data);
     data->maxSize = QWIDGETSIZE_MAX;
-    data->skipInPreferred = 1;
 
     // Save a reference to layout vertices
     layoutFirstVertex[Horizontal] = internalVertex(layout, Qt::AnchorLeft);
@@ -1284,7 +1283,6 @@ void QGraphicsAnchorLayoutPrivate::createLayoutEdges()
     addAnchor_helper(layout, Qt::AnchorTop, layout,
                      Qt::AnchorBottom, data);
     data->maxSize = QWIDGETSIZE_MAX;
-    data->skipInPreferred = 1;
 
     // Save a reference to layout vertices
     layoutFirstVertex[Vertical] = internalVertex(layout, Qt::AnchorTop);
@@ -2700,7 +2698,9 @@ bool QGraphicsAnchorLayoutPrivate::solvePreferred(const QList<QSimplexConstraint
     //
     for (int i = 0; i < variables.size(); ++i) {
         AnchorData *ad = variables.at(i);
-        if (ad->skipInPreferred)
+
+        // The layout original structure anchors are not relevant in preferred size calculation
+        if (ad->isLayoutAnchor)
             continue;
 
         QSimplexVariable *grower = new QSimplexVariable;
diff --git a/src/gui/graphicsview/qgraphicsanchorlayout_p.h b/src/gui/graphicsview/qgraphicsanchorlayout_p.h
index 2b365fb..8529e2e 100644
--- a/src/gui/graphicsview/qgraphicsanchorlayout_p.h
+++ b/src/gui/graphicsview/qgraphicsanchorlayout_p.h
@@ -124,8 +124,7 @@ struct AnchorData : public QSimplexVariable {
         : QSimplexVariable(), from(0), to(0),
           minSize(0), prefSize(0), maxSize(0),
           sizeAtMinimum(0), sizeAtPreferred(0),
-          sizeAtMaximum(0), item(0),
-          graphicsAnchor(0), skipInPreferred(0),
+          sizeAtMaximum(0), item(0), graphicsAnchor(0),
           type(Normal), isLayoutAnchor(false),
           isCenterAnchor(false), orientation(0),
           dependency(Independent) {}
@@ -169,7 +168,6 @@ struct AnchorData : public QSimplexVariable {
     QGraphicsLayoutItem *item;
     QGraphicsAnchor *graphicsAnchor;
 
-    uint skipInPreferred : 1;
     uint type : 2;            // either Normal, Sequential or Parallel
     uint isLayoutAnchor : 1;  // if this anchor is an internal layout anchor
     uint isCenterAnchor : 1;
diff --git a/tests/auto/qgraphicsanchorlayout/tst_qgraphicsanchorlayout.cpp b/tests/auto/qgraphicsanchorlayout/tst_qgraphicsanchorlayout.cpp
index 2ad024f..4f8c240 100644
--- a/tests/auto/qgraphicsanchorlayout/tst_qgraphicsanchorlayout.cpp
+++ b/tests/auto/qgraphicsanchorlayout/tst_qgraphicsanchorlayout.cpp
@@ -86,6 +86,7 @@ private slots:
     void parallelSimplificationOfCenter();
     void simplificationVsRedundance();
     void spacingPersistency();
+    void snakeParallelWithLayout();
 };
 
 class RectWidget : public QGraphicsWidget
@@ -1892,5 +1893,56 @@ void tst_QGraphicsAnchorLayout::spacingPersistency()
     QCOMPARE(anchor->spacing(), 30.0);
 }
 
+/*
+    Test whether a correct preferred size is set when a "snake" sequence is in parallel with the
+    layout or half of the layout. The tricky thing here is that all items on the snake should
+    keep their preferred sizes.
+*/
+void tst_QGraphicsAnchorLayout::snakeParallelWithLayout()
+{
+    QSizeF min(10, 20);
+    QSizeF pref(50, 20);
+    QSizeF max(100, 20);
+
+    QGraphicsWidget *a = createItem(max, max, max, "A");
+    QGraphicsWidget *b = createItem(min, pref, max, "B");
+    QGraphicsWidget *c = createItem(max, max, max, "C");
+
+    QGraphicsWidget parent;
+    QGraphicsAnchorLayout *l = new QGraphicsAnchorLayout(&parent);
+    l->setContentsMargins(0, 0, 0, 0);
+    l->setSpacing(0);
+
+    // First we'll do the case in parallel with the entire layout...
+    l->addAnchor(l, Qt::AnchorLeft, a, Qt::AnchorLeft);
+    l->addAnchor(a, Qt::AnchorRight, b, Qt::AnchorRight);
+    l->addAnchor(b, Qt::AnchorLeft, c, Qt::AnchorLeft);
+    l->addAnchor(c, Qt::AnchorRight, l, Qt::AnchorRight);
+
+    l->addAnchor(l, Qt::AnchorTop, a, Qt::AnchorTop);
+    l->addAnchor(a, Qt::AnchorBottom, b, Qt::AnchorTop);
+    l->addAnchor(b, Qt::AnchorBottom, c, Qt::AnchorTop);
+    l->addAnchor(c, Qt::AnchorBottom, l, Qt::AnchorBottom);
+
+    parent.resize(l->effectiveSizeHint(Qt::PreferredSize));
+
+    // Note that A and C are fixed in the maximum size
+    QCOMPARE(l->geometry(), QRectF(QPointF(0, 0), QSizeF(150, 60)));
+    QCOMPARE(a->geometry(), QRectF(QPointF(0, 0), max));
+    QCOMPARE(b->geometry(), QRectF(QPointF(50, 20), pref));
+    QCOMPARE(c->geometry(), QRectF(QPointF(50, 40), max));
+
+    // Then, we change the "snake" to be in parallel with half of the layout
+    delete l->anchor(c, Qt::AnchorRight, l, Qt::AnchorRight);
+    l->addAnchor(c, Qt::AnchorRight, l, Qt::AnchorHorizontalCenter);
+
+    parent.resize(l->effectiveSizeHint(Qt::PreferredSize));
+
+    QCOMPARE(l->geometry(), QRectF(QPointF(0, 0), QSizeF(300, 60)));
+    QCOMPARE(a->geometry(), QRectF(QPointF(0, 0), max));
+    QCOMPARE(b->geometry(), QRectF(QPointF(50, 20), pref));
+    QCOMPARE(c->geometry(), QRectF(QPointF(50, 40), max));
+}
+
 QTEST_MAIN(tst_QGraphicsAnchorLayout)
 #include "tst_qgraphicsanchorlayout.moc"