QPainter not restored correctly in Graphics View.

World transform and opacity was sometimes not restored correctly after
drawing items.

Auto test included.

Task-number: Discovered while working on QTBUG-12760

2 files changed, 4 insertions, 1 deletions

diff --git a/src/gui/graphicsview/qgraphicsscene.cpp b/src/gui/graphicsview/qgraphicsscene.cpp
index 38612a8..8dc15bf 100644
--- a/src/gui/graphicsview/qgraphicsscene.cpp
+++ b/src/gui/graphicsview/qgraphicsscene.cpp
@@ -5305,6 +5305,7 @@ void QGraphicsScene::drawItems(QPainter *painter,
     if (!d->unpolishedItems.isEmpty())
         d->_q_polishItems();
 
+    const qreal opacity = painter->opacity();
     QTransform viewTransform = painter->worldTransform();
     Q_UNUSED(options);
 
@@ -5338,6 +5339,7 @@ void QGraphicsScene::drawItems(QPainter *painter,
         topLevelItems.at(i)->d_ptr->itemDiscovered = 0;
 
     painter->setWorldTransform(viewTransform);
+    painter->setOpacity(opacity);
 }
 
 /*!
diff --git a/src/gui/graphicsview/qgraphicsview.cpp b/src/gui/graphicsview/qgraphicsview.cpp
index c8aca80..a566c8e 100644
--- a/src/gui/graphicsview/qgraphicsview.cpp
+++ b/src/gui/graphicsview/qgraphicsview.cpp
@@ -3475,7 +3475,8 @@ void QGraphicsView::paintEvent(QPaintEvent *event)
         // IndirectPainting (the else branch), because in that case we always save()
         // and restore() in QGraphicsScene::drawItems().
         if (!d->scene->d_func()->painterStateProtection)
-            painter.setWorldTransform(viewTransform);
+            painter.setOpacity(1.0);
+        painter.setWorldTransform(viewTransform);
     } else {
         // Make sure we don't have unpolished items before we draw
         if (!d->scene->d_func()->unpolishedItems.isEmpty())