2 files changed, 25 insertions, 10 deletions

diff --git a/src/gui/graphicsview/qgraphicsanchorlayout_p.cpp b/src/gui/graphicsview/qgraphicsanchorlayout_p.cpp
index dbfce74..ad7d657 100644
--- a/src/gui/graphicsview/qgraphicsanchorlayout_p.cpp
+++ b/src/gui/graphicsview/qgraphicsanchorlayout_p.cpp
@@ -1080,12 +1080,14 @@ void QGraphicsAnchorLayoutPrivate::createCenterAnchors(
     c->variables.insert(data, 1.0);
     addAnchor_helper(item, firstEdge, item, centerEdge, data);
     data->isCenterAnchor = true;
+    data->dependency = AnchorData::Master;
     data->refreshSizeHints(0);
 
     data = new AnchorData;
     c->variables.insert(data, -1.0);
     addAnchor_helper(item, centerEdge, item, lastEdge, data);
     data->isCenterAnchor = true;
+    data->dependency = AnchorData::Slave;
     data->refreshSizeHints(0);
 
     itemCenterConstraints[orientation].append(c);
@@ -2075,19 +2077,18 @@ QList<QSimplexConstraint *> QGraphicsAnchorLayoutPrivate::constraintsFromSizeHin
     // Look for the layout edge. That can be either the first half in case the
     // layout is split in two, or the whole layout anchor.
     Orientation orient = Orientation(anchors.first()->orientation);
-    AnchorData *layoutEdge1 = NULL;
-    AnchorData *layoutEdge2 = NULL;
+    AnchorData *layoutEdge = NULL;
     if (layoutCentralVertex[orient]) {
-        layoutEdge1 = graph[orient].edgeData(layoutFirstVertex[orient], layoutCentralVertex[orient]);
-        layoutEdge2 = graph[orient].edgeData(layoutCentralVertex[orient], layoutLastVertex[orient]);
+        layoutEdge = graph[orient].edgeData(layoutFirstVertex[orient], layoutCentralVertex[orient]);
     } else {
-        layoutEdge1 = graph[orient].edgeData(layoutFirstVertex[orient], layoutLastVertex[orient]);
+        layoutEdge = graph[orient].edgeData(layoutFirstVertex[orient], layoutLastVertex[orient]);
+
         // If maxSize is less then "infinite", that means there are other anchors
         // grouped together with this one. We can't ignore its maximum value so we
         // set back the variable to NULL to prevent the continue condition from being
         // satisfied in the loop below.
-        if (layoutEdge1->maxSize < QWIDGETSIZE_MAX)
-            layoutEdge1 = NULL;
+        if (layoutEdge->maxSize < QWIDGETSIZE_MAX)
+            layoutEdge = NULL;
     }
 
     // For each variable, create constraints based on size hints
@@ -2096,6 +2097,12 @@ QList<QSimplexConstraint *> QGraphicsAnchorLayoutPrivate::constraintsFromSizeHin
     for (int i = 0; i < anchors.size(); ++i) {
         AnchorData *ad = anchors[i];
 
+        // Anchors that have their size directly linked to another one don't need constraints
+        // For exammple, the second half of an item has exactly the same size as the first half
+        // thus constraining the latter is enough.
+        if (ad->dependency == AnchorData::Slave)
+            continue;
+
         if ((ad->minSize == ad->maxSize) || qFuzzyCompare(ad->minSize, ad->maxSize)) {
             QSimplexConstraint *c = new QSimplexConstraint;
             c->variables.insert(ad, 1.0);
@@ -2113,7 +2120,7 @@ QList<QSimplexConstraint *> QGraphicsAnchorLayoutPrivate::constraintsFromSizeHin
             // We avoid adding restrictions to the layout internal anchors. That's
             // to prevent unnecessary fair distribution from happening due to this
             // artificial restriction.
-            if ((ad == layoutEdge1) || (ad == layoutEdge2))
+            if (ad == layoutEdge)
                 continue;
 
             c = new QSimplexConstraint;
@@ -2128,7 +2135,7 @@ QList<QSimplexConstraint *> QGraphicsAnchorLayoutPrivate::constraintsFromSizeHin
     // If no upper boundary restriction was added, add one to avoid unbounded problem
     if (unboundedProblem) {
         QSimplexConstraint *c = new QSimplexConstraint;
-        c->variables.insert(layoutEdge1, 1.0);
+        c->variables.insert(layoutEdge, 1.0);
         c->constant = QWIDGETSIZE_MAX;
         c->ratio = QSimplexConstraint::LessOrEqual;
         anchorConstraints += c;
diff --git a/src/gui/graphicsview/qgraphicsanchorlayout_p.h b/src/gui/graphicsview/qgraphicsanchorlayout_p.h
index 7d7bdb6..2f0237c 100644
--- a/src/gui/graphicsview/qgraphicsanchorlayout_p.h
+++ b/src/gui/graphicsview/qgraphicsanchorlayout_p.h
@@ -150,6 +150,12 @@ struct AnchorData : public QSimplexVariable {
         Parallel
     };
 
+    enum Dependency {
+        Independent = 0,
+        Master,
+        Slave
+    };
+
     AnchorData()
         : QSimplexVariable(), item(0), from(0), to(0),
           minSize(0), prefSize(0), expSize(0), maxSize(0),
@@ -157,7 +163,8 @@ struct AnchorData : public QSimplexVariable {
           sizeAtExpanding(0), sizeAtMaximum(0),
           graphicsAnchor(0), skipInPreferred(0),
           type(Normal), hasSize(true), isLayoutAnchor(false),
-          isCenterAnchor(false), orientation(0) {}
+          isCenterAnchor(false), orientation(0),
+          dependency(Independent) {}
 
     virtual void updateChildrenSizes() {}
     virtual bool refreshSizeHints(const QLayoutStyleInfo *styleInfo);
@@ -212,6 +219,7 @@ struct AnchorData : public QSimplexVariable {
     uint isLayoutAnchor : 1;  // if this anchor is an internal layout anchor
     uint isCenterAnchor : 1;
     uint orientation : 1;
+    uint dependency : 2;      // either Independent, Master or Slave
 };
 
 #ifdef QT_DEBUG