From 8ff4f09b02e274c997d5083ce7baf3e45036133b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jan=20Arve=20S=C3=A6ther?= <jan-arve.saether@qt.io>
Date: Fri, 10 Mar 2023 13:52:42 +0100
Subject: [PATCH] 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 24f5695d35f0ef7a8f48502de3d4810d21fb3d3f)
---
 src/quicklayouts/qquicklinearlayout.cpp       |  4 ++
 .../qquicklayouts/data/tst_rowlayout.qml      | 39 ++++++++++++++++++-
 2 files changed, 42 insertions(+), 1 deletion(-)

diff --git a/src/quicklayouts/qquicklinearlayout.cpp b/src/quicklayouts/qquicklinearlayout.cpp
index 116678c1d0..b34815e449 100644
--- a/src/quicklayouts/qquicklinearlayout.cpp
+++ b/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();
diff --git a/tests/auto/quick/qquicklayouts/data/tst_rowlayout.qml b/tests/auto/quick/qquicklayouts/data/tst_rowlayout.qml
index 506893b631..7f7352e25b 100644
--- a/tests/auto/quick/qquicklayouts/data/tst_rowlayout.qml
+++ b/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)
+        }
+    }
 }