Fix buglet in QGraphicsItem::stackBefore().

Reported by Alan. The stackBefore() implementation did not alter the
insertion order if the two items' current Z values were different. The
fix is to ensure it is updated, so that the stackBefore() operation
takes effect should the Z values become equal in the future. Example:

Current order: A-B-C-D
A->setZValue(1);
Current order: B-C-D-A (A moves to the end)
D->stackBefore(A);
Current order: B-C-D-A (unchanged, D is already before A)
A->setZValue(0);
Current order: D-A-B-C (now A moves back, and D moves in front)

Reviewed-by: Aaron Kennedy

1 files changed, 1 insertions, 1 deletions

diff --git a/src/gui/graphicsview/qgraphicsitem.cpp b/src/gui/graphicsview/qgraphicsitem.cpp
index 4b2ff52..ad672a3 100644
--- a/src/gui/graphicsview/qgraphicsitem.cpp
+++ b/src/gui/graphicsview/qgraphicsitem.cpp
@@ -4261,7 +4261,7 @@ void QGraphicsItem::stackBefore(const QGraphicsItem *sibling)
     // Only move items with the same Z value, and that need moving.
     int siblingIndex = sibling->d_ptr->siblingIndex;
     int myIndex = d_ptr->siblingIndex;
-    if (myIndex >= siblingIndex && d_ptr->z == sibling->d_ptr->z) {
+    if (myIndex >= siblingIndex) {
         siblings->move(myIndex, siblingIndex);
         // Fixup the insertion ordering.
         for (int i = 0; i < siblings->size(); ++i) {