Do not crash if resizing a layout that got its child destroyed

Normally updatePolish() would call ensureLayoutItemsUpdated(), but in
some cases the layout might be resized before the updatePolish() is
processed.
We therefore have to also call ensureLayoutItemsUpdated() from rearrange()

Fixes: QTBUG-111792
Change-Id: Iab24dafc26dfa86975348c92244034f7ff825e5f
Reviewed-by: Oliver Eftevaag <oliver.eftevaag@qt.io>
(cherry picked from commit 24f5695d35)

src/quicklayouts/qquicklinearlayout.cpp

@@ -457,6 +457,10 @@ void QQuickGridLayoutBase::rearrange(const QSizeF &size)
         return;
     }
 
+    // Should normally not be needed, but there might be an incoming window resize event that we
+    // will process before we process updatePolish()
+    ensureLayoutItemsUpdated(QQuickLayout::ApplySizeHints | QQuickLayout::Recursive);
+
     d->m_rearranging = true;
     qCDebug(lcQuickLayouts) << objectName() << "QQuickGridLayoutBase::rearrange()" << size;
     Qt::LayoutDirection visualDir = effectiveLayoutDirection();

tests/auto/quick/qquicklayouts/data/tst_rowlayout.qml

@@ -1470,6 +1470,43 @@ Item {
             verify(!BindingLoopDetector.bindingLoopDetected, "Detected binding loop")
             BindingLoopDetector.reset()
         }
-    }
 
+
+        //---------------------------
+        // QTBUG-111792
+        Component {
+            id: rowlayoutCrashes_Component
+            RowLayout {
+                spacing: 5
+                Rectangle {
+                    color: "red"
+                    implicitWidth: 10
+                    implicitHeight: 10
+                }
+                Rectangle {
+                    color: "green"
+                    implicitWidth: 10
+                    implicitHeight: 10
+                }
+            }
+        }
+
+        function test_dontCrashAfterDestroyingChildren_data() {
+            return [
+                        { tag: "setWidth", func: function (layout) { layout.width = 42 } },
+                        { tag: "setHeight", func: function (layout) { layout.height = 42 } },
+                        { tag: "getImplicitWidth", func: function (layout) { let x = layout.implicitWidth } },
+                        { tag: "getImplicitHeight", func: function (layout) { let x = layout.implicitHeight } },
+                    ]
+        }
+
+        function test_dontCrashAfterDestroyingChildren(data) {
+            var layout = createTemporaryObject(rowlayoutCrashes_Component, container)
+            waitForRendering(layout)
+            compare(layout.implicitWidth, 25)
+            layout.children[0].destroy()    // deleteLater()
+            wait(0)                         // process the scheduled delete and actually invoke the dtor
+            data.func(layout)               // call a function that might ultimately access the deleted item (but shouldn't)
+        }
+    }
 }