From 7a5fa8af2d0c3329dd1962d6b053388a960f8305 Mon Sep 17 00:00:00 2001
From: Olivier Goffart <olivier.goffart@nokia.com>
Date: Thu, 19 Aug 2010 16:00:57 +0200
Subject: QGraphicsView: Fix assert that may occurs if there are 'empty' item
 to draw, and changed() signal connected

Reviewed-by: bnilsen
---
 src/gui/graphicsview/qgraphicsscene.cpp          |  4 +++-
 tests/auto/qgraphicsscene/tst_qgraphicsscene.cpp | 26 ++++++++++++++++++++++++
 2 files changed, 29 insertions(+), 1 deletion(-)

diff --git a/src/gui/graphicsview/qgraphicsscene.cpp b/src/gui/graphicsview/qgraphicsscene.cpp
index a98ce6f..3c23884 100644
--- a/src/gui/graphicsview/qgraphicsscene.cpp
+++ b/src/gui/graphicsview/qgraphicsscene.cpp
@@ -5126,7 +5126,9 @@ void QGraphicsScenePrivate::processDirtyItemsRecursive(QGraphicsItem *item, bool
                 q->update(itemBoundingRect.translated(item->d_ptr->sceneTransform.dx(),
                                                       item->d_ptr->sceneTransform.dy()));
             } else {
-                q->update(item->d_ptr->sceneTransform.mapRect(itemBoundingRect));
+                QRectF rect = item->d_ptr->sceneTransform.mapRect(itemBoundingRect);
+                if (!rect.isEmpty())
+                    q->update(rect);
             }
         } else {
             QRectF dirtyRect;
diff --git a/tests/auto/qgraphicsscene/tst_qgraphicsscene.cpp b/tests/auto/qgraphicsscene/tst_qgraphicsscene.cpp
index 903977c..7ee2a48 100644
--- a/tests/auto/qgraphicsscene/tst_qgraphicsscene.cpp
+++ b/tests/auto/qgraphicsscene/tst_qgraphicsscene.cpp
@@ -276,6 +276,7 @@ private slots:
     void isActive();
     void siblingIndexAlwaysValid();
     void removeFullyTransparentItem();
+    void zeroScale();
 
     // task specific tests below me
     void task139710_bspTreeCrash();
@@ -4564,5 +4565,30 @@ void tst_QGraphicsScene::taskQTBUG_7863_paintIntoCacheWithTransparentParts()
     }
 }
 
+void tst_QGraphicsScene::zeroScale()
+{
+    //should not crash
+    QGraphicsScene scene;
+    scene.setSceneRect(-100, -100, 100, 100);
+    QGraphicsView view(&scene);
+
+    ChangedListener cl;
+    connect(&scene, SIGNAL(changed(const QList<QRectF> &)), &cl, SLOT(changed(const QList<QRectF> &)));
+
+    QGraphicsRectItem *rect1 = new QGraphicsRectItem(0, 0, 0.0000001, 0.00000001);
+    scene.addItem(rect1);
+    rect1->setRotation(82);
+    rect1->setScale(0.00000001);
+
+    QApplication::processEvents();
+    QCOMPARE(cl.changes.count(), 1);
+    QGraphicsRectItem *rect2 = new QGraphicsRectItem(-0.0000001, -0.0000001, 0.0000001, 0.0000001);
+    rect2->setScale(0.00000001);
+    scene.addItem(rect2);
+    rect1->setPos(20,20);
+    QApplication::processEvents();
+    QCOMPARE(cl.changes.count(), 2);
+}
+
 QTEST_MAIN(tst_QGraphicsScene)
 #include "tst_qgraphicsscene.moc"
-- 
cgit v0.12