QQmlObjectModel: Do not store attached objects in global static

This is rather dangerous. The global static is not protected in any way
against concurrent access. However, we already have a place to store
attached objects. The base object's QQmlData. Just use that.

Pick-to: 6.8
Task-number: QTBUG-124345
Change-Id: I5f254e640f836016564f297d2f39ea40e037acd8
Reviewed-by: Fabian Kosmale <[email protected]>
Reviewed-by: Sami Shalayel <[email protected]>
Reviewed-by: Olivier De Cannière <[email protected]>

1 files changed, 24 insertions, 22 deletions

diff --git a/src/qmlmodels/qqmlobjectmodel.cpp b/src/qmlmodels/qqmlobjectmodel.cpp
index 4921010911..fb98b330d9 100644
--- a/src/qmlmodels/qqmlobjectmodel.cpp
+++ b/src/qmlmodels/qqmlobjectmodel.cpp
@@ -18,9 +18,6 @@
 
 QT_BEGIN_NAMESPACE
 
-QHash<QObject*, QQmlObjectModelAttached*> QQmlObjectModelAttached::attachedProperties;
-
-
 class QQmlObjectModelPrivate : public QObjectPrivate
 {
     Q_DECLARE_PUBLIC(QQmlObjectModel)
@@ -67,10 +64,8 @@ public:
     void insert(int index, QObject *item) {
         Q_Q(QQmlObjectModel);
         children.insert(index, Item(item));
-        for (int i = index; i < children.size(); ++i) {
-            QQmlObjectModelAttached *attached = QQmlObjectModelAttached::properties(children.at(i).item);
-            attached->setIndex(i);
-        }
+        for (int i = index, end = children.size(); i < end; ++i)
+            setIndex(i);
         QQmlChangeSet changeSet;
         changeSet.insert(index, 1);
         emit q->modelUpdated(changeSet, false);
@@ -80,10 +75,9 @@ public:
 
     void replace(int index, QObject *item) {
         Q_Q(QQmlObjectModel);
-        auto *attached = QQmlObjectModelAttached::properties(children.at(index).item);
-        attached->setIndex(-1);
+        clearIndex(index);
         children.replace(index, Item(item));
-        QQmlObjectModelAttached::properties(children.at(index).item)->setIndex(index);
+        setIndex(index);
         QQmlChangeSet changeSet;
         changeSet.change(index, 1);
         emit q->modelUpdated(changeSet, false);
@@ -107,10 +101,9 @@ public:
         for (int i = 0; i < n; ++i)
             store.append(children[from + i]);
 
-        for (int i = 0; i < store.count(); ++i) {
+        for (int i = 0, end = store.count(); i < end; ++i) {
             children[from + i] = store[i];
-            QQmlObjectModelAttached *attached = QQmlObjectModelAttached::properties(children.at(from + i).item);
-            attached->setIndex(from + i);
+            setIndex(from + i);
         }
 
         QQmlChangeSet changeSet;
@@ -121,15 +114,11 @@ public:
 
     void remove(int index, int n) {
         Q_Q(QQmlObjectModel);
-        for (int i = index; i < index + n; ++i) {
-            QQmlObjectModelAttached *attached = QQmlObjectModelAttached::properties(children.at(i).item);
-            attached->setIndex(-1);
-        }
+        for (int i = index; i < index + n; ++i)
+            clearIndex(i);
         children.erase(children.begin() + index, children.begin() + index + n);
-        for (int i = index; i < children.size(); ++i) {
-            QQmlObjectModelAttached *attached = QQmlObjectModelAttached::properties(children.at(i).item);
-            attached->setIndex(i);
-        }
+        for (int i = index, end = children.size(); i < end; ++i)
+            setIndex(i);
         QQmlChangeSet changeSet;
         changeSet.remove(index, n);
         emit q->modelUpdated(changeSet, false);
@@ -152,6 +141,19 @@ public:
         return -1;
     }
 
+private:
+    void setIndex(int child, int index)
+    {
+        if (auto *attached = static_cast<QQmlObjectModelAttached *>(
+                    qmlAttachedPropertiesObject<QQmlObjectModel>(children.at(child).item))) {
+            attached->setIndex(index);
+        }
+    }
+
+    void setIndex(int child) { setIndex(child, child); }
+    void clearIndex(int child) { setIndex(child, -1); }
+
+
     uint moveId;
     QList<Item> children;
 };
@@ -283,7 +285,7 @@ int QQmlObjectModel::indexOf(QObject *item, QObject *) const
 
 QQmlObjectModelAttached *QQmlObjectModel::qmlAttachedProperties(QObject *obj)
 {
-    return QQmlObjectModelAttached::properties(obj);
+    return new QQmlObjectModelAttached(obj);
 }
 
 /*!