Fix sorting bug when using BSP tree index + add autotest.

We use stable sorting to keep insertion order. This works fine as long
as we sort a complete list of siblings in one go, and this list already
has items in insertion order. But if we shuffle such a list, the only
way to get proper sort order again (with insertion order intact), is
if each item has a sibling index. We used to have this, but we don't
have it anymore (as it's not needed for NoIndex mode).

So until we separate the BSP index into a separate class and add this
index there, we add this workaround which uses the toplevelitems list
to ensure the items have the correct order.

Reviewed-by: bnilsen

1 files changed, 2 insertions, 6 deletions

diff --git a/src/gui/graphicsview/qgraphicsitem.cpp b/src/gui/graphicsview/qgraphicsitem.cpp
index db16213..f50d210 100644
--- a/src/gui/graphicsview/qgraphicsitem.cpp
+++ b/src/gui/graphicsview/qgraphicsitem.cpp
@@ -6190,10 +6190,8 @@ void QGraphicsItem::addToIndex()
         // ### add to child index only if applicable
         return;
     }
-    if (d_ptr->scene) {
+    if (d_ptr->scene)
         d_ptr->scene->d_func()->addToIndex(this);
-        d_ptr->scene->d_func()->markDirty(this);
-    }
 }
 
 /*!
@@ -6209,10 +6207,8 @@ void QGraphicsItem::removeFromIndex()
         // ### remove from child index only if applicable
         return;
     }
-    if (d_ptr->scene) {
-        d_ptr->scene->d_func()->markDirty(this);
+    if (d_ptr->scene)
         d_ptr->scene->d_func()->removeFromIndex(this);
-    }
 }
 
 /*!