From 37aef8c7d55d3f5bf036d66613e87f89fcd9b897 Mon Sep 17 00:00:00 2001
From: Michael Brasser <michael.brasser@nokia.com>
Date: Fri, 6 Nov 2009 15:33:45 +1000
Subject: Fix crash when using anchors inside a positioner.

Task-number: QTBUG-5428
---
 .../graphicsitems/qmlgraphicsanchors.cpp           | 47 +++++++++++++++-------
 .../graphicsitems/qmlgraphicsanchors_p_p.h         |  4 +-
 tests/auto/declarative/anchors/data/crash1.qml     | 11 +++++
 tests/auto/declarative/anchors/tst_anchors.cpp     | 15 +++++++
 4 files changed, 62 insertions(+), 15 deletions(-)
 create mode 100644 tests/auto/declarative/anchors/data/crash1.qml

diff --git a/src/declarative/graphicsitems/qmlgraphicsanchors.cpp b/src/declarative/graphicsitems/qmlgraphicsanchors.cpp
index 404daad..f6dc5fd 100644
--- a/src/declarative/graphicsitems/qmlgraphicsanchors.cpp
+++ b/src/declarative/graphicsitems/qmlgraphicsanchors.cpp
@@ -152,13 +152,23 @@ void QmlGraphicsAnchorsPrivate::fillChanged()
     if (!fill || !isItemComplete())
         return;
 
-    if (fill == item->parentItem()) {                         //child-parent
-        setItemPos(QPointF(leftMargin, topMargin));
-    } else if (fill->parentItem() == item->parentItem()) {   //siblings
-        setItemPos(QPointF(fill->x()+leftMargin, fill->y()+topMargin));
+    if (updatingFill < 2) {
+        ++updatingFill;
+
+        if (fill == item->parentItem()) {                         //child-parent
+            setItemPos(QPointF(leftMargin, topMargin));
+        } else if (fill->parentItem() == item->parentItem()) {   //siblings
+            setItemPos(QPointF(fill->x()+leftMargin, fill->y()+topMargin));
+        }
+        setItemWidth(fill->width()-leftMargin-rightMargin);
+        setItemHeight(fill->height()-topMargin-bottomMargin);
+
+        --updatingFill;
+    } else {
+        // ### Make this certain :)
+        qmlInfo(QmlGraphicsAnchors::tr("Possible anchor loop detected on fill."), item);
     }
-    setItemWidth(fill->width()-leftMargin-rightMargin);
-    setItemHeight(fill->height()-topMargin-bottomMargin);
+
 }
 
 void QmlGraphicsAnchorsPrivate::centerInChanged()
@@ -166,16 +176,25 @@ void QmlGraphicsAnchorsPrivate::centerInChanged()
     if (!centerIn || fill || !isItemComplete())
         return;
 
-    if (centerIn == item->parentItem()) {
-        QPointF p((item->parentItem()->width() - item->width()) / 2.,
-                  (item->parentItem()->height() - item->height()) / 2.);
-        setItemPos(p);
+    if (updatingCenterIn < 2) {
+        ++updatingCenterIn;
 
-    } else if (centerIn->parentItem() == item->parentItem()) {
+        if (centerIn == item->parentItem()) {
+            QPointF p((item->parentItem()->width() - item->width()) / 2.,
+                      (item->parentItem()->height() - item->height()) / 2.);
+            setItemPos(p);
 
-        QPointF p(centerIn->x() + (centerIn->width() - item->width()) / 2.,
-                  centerIn->y() + (centerIn->height() - item->height()) / 2.);
-        setItemPos(p);
+        } else if (centerIn->parentItem() == item->parentItem()) {
+
+            QPointF p(centerIn->x() + (centerIn->width() - item->width()) / 2.,
+                      centerIn->y() + (centerIn->height() - item->height()) / 2.);
+            setItemPos(p);
+        }
+
+        --updatingCenterIn;
+    } else {
+        // ### Make this certain :)
+        qmlInfo(QmlGraphicsAnchors::tr("Possible anchor loop detected on centerIn."), item);
     }
 }
 
diff --git a/src/declarative/graphicsitems/qmlgraphicsanchors_p_p.h b/src/declarative/graphicsitems/qmlgraphicsanchors_p_p.h
index 5f8b2c1..d21d9c5 100644
--- a/src/declarative/graphicsitems/qmlgraphicsanchors_p_p.h
+++ b/src/declarative/graphicsitems/qmlgraphicsanchors_p_p.h
@@ -89,7 +89,7 @@ class QmlGraphicsAnchorsPrivate : public QObjectPrivate
 public:
     QmlGraphicsAnchorsPrivate()
       : updatingMe(false), updatingHorizontalAnchor(0),
-        updatingVerticalAnchor(0), item(0), usedAnchors(0), fill(0),
+        updatingVerticalAnchor(0), updatingFill(0), updatingCenterIn(0), item(0), usedAnchors(0), fill(0),
         centerIn(0), leftMargin(0), rightMargin(0), topMargin(0),
         bottomMargin(0), vCenterOffset(0), hCenterOffset(0), baselineOffset(0),
         componentComplete(true)
@@ -109,6 +109,8 @@ public:
     bool updatingMe;
     int updatingHorizontalAnchor;
     int updatingVerticalAnchor;
+    int updatingFill;
+    int updatingCenterIn;
 
     void setItemHeight(qreal);
     void setItemWidth(qreal);
diff --git a/tests/auto/declarative/anchors/data/crash1.qml b/tests/auto/declarative/anchors/data/crash1.qml
new file mode 100644
index 0000000..fd9dc55
--- /dev/null
+++ b/tests/auto/declarative/anchors/data/crash1.qml
@@ -0,0 +1,11 @@
+import Qt 4.6
+
+Column {
+    Text {
+        text: "foo"
+        anchors.fill: parent
+    }
+    Text {
+        text: "bar"
+    }
+}
diff --git a/tests/auto/declarative/anchors/tst_anchors.cpp b/tests/auto/declarative/anchors/tst_anchors.cpp
index c3a857c..4c85d2d 100644
--- a/tests/auto/declarative/anchors/tst_anchors.cpp
+++ b/tests/auto/declarative/anchors/tst_anchors.cpp
@@ -62,6 +62,7 @@ private slots:
     void illegalSets();
     void reset();
     void nullItem();
+    void crash1();
 };
 
 /*
@@ -248,6 +249,20 @@ void tst_anchors::nullItem()
     item->anchors()->setBottom(anchor);
 }
 
+void tst_anchors::crash1()
+{
+    QmlView *view = new QmlView;
+
+    view->setUrl(QUrl("file://" SRCDIR "/data/crash1.qml"));
+
+    QString expect = "QML QmlGraphicsText (" + view->url().toString() + ":4:5" + ") Possible anchor loop detected on fill.";
+    QTest::ignoreMessage(QtWarningMsg, expect.toLatin1());
+    view->execute();
+    qApp->processEvents();
+
+    delete view;
+}
+
 QTEST_MAIN(tst_anchors)
 
 #include "tst_anchors.moc"
-- 
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