Fix z-value of QGraphicsItems being ignored during draw

In QGraphicsScene's function draw, don't copy the children into a
const copy (to prevent detaching in the loops), as they might get
sorted. Instead, use a const reference.

Amends e349f787d595aa343ca86af94159b6730d55b8d5, which introduced
the bug by making a copy of the unsorted list.

Fixes: QTBUG-81316
Change-Id: Iab9b87e75178a883806088a9db234c7a2aaa9301
Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@qt.io>
Reviewed-by: Edward Welbourne <edward.welbourne@qt.io>
(cherry picked from commit 269fdef53d98386b714bf6852a1f214e9159faa1)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>
This commit is contained in:
Qiang Li 2021-02-24 20:49:07 +08:00 committed by Qt Cherry-pick Bot
parent 1b1f2b265e
commit 3dca0aaf09

View File

@ -4821,7 +4821,7 @@ void QGraphicsScenePrivate::draw(QGraphicsItem *item, QPainter *painter, const Q
qreal opacity, const QTransform *effectTransform,
bool wasDirtyParentSceneTransform, bool drawItem)
{
const auto children = item->d_ptr->children;
const auto &children = item->d_ptr->children;
const bool itemIsFullyTransparent = QGraphicsItemPrivate::isOpacityNull(opacity);
const bool itemClipsChildrenToShape = (item->d_ptr->flags & QGraphicsItem::ItemClipsChildrenToShape);