Merge remote-tracking branch 'refs/remotes/origin/master'

repo/task-api/src/main/java/com/evolveum/midpoint/task/api/Task.java

@@ -807,7 +807,7 @@ default List<? extends Task> listSubtasks(OperationResult parentResult) throws S
     /**
      * Changes in-memory representation immediately and schedules a corresponding batched modification.
      */
-    void modify(ItemDelta<?, ?> delta) throws SchemaException;
+    void modify(@NotNull ItemDelta<?, ?> delta) throws SchemaException;
 
     /**
      * Applies given collection of deltas.

repo/task-api/src/main/java/com/evolveum/midpoint/task/api/test/NullTaskImpl.java

@@ -614,7 +614,7 @@ public OperationStatsType getStoredOperationStatsOrClone() {
         return null;
     }
 
-    @Override public void modify(ItemDelta<?, ?> delta) {
+    @Override public void modify(@NotNull ItemDelta<?, ?> delta) {
     }
 
     public void modifyAndFlush(ItemDelta<?, ?> delta, OperationResult result) {

repo/task-quartz-impl/src/main/java/com/evolveum/midpoint/task/quartzimpl/TaskQuartzImpl.java

@@ -354,10 +354,15 @@ void addPendingModification(ItemDelta<?, ?> delta) {
     }
 
     @Override
-    public void modify(ItemDelta<?, ?> delta) throws SchemaException {
+    public void modify(@NotNull ItemDelta<?, ?> delta) throws SchemaException {
         LOGGER.debug("Applying {} to {}", delta, this);
         if (isPersistent()) {
-            addPendingModification(delta);
+            // If we not cloned the delta, another thread might attempt to modify it, failing with CME
+            // (conflicting with delta.applyTo below). Note that deltas are not thread-safe. See MID-7264.
+            // An alternative would be to guard this code by prismAccess, along with the delta application below.
+            // But it would make delta accessible to a different thread nevertheless. The caller should be cautious
+            // not to access the delta after the call. We don't want to impose this restriction to the callers.
+            addPendingModification(delta.clone());
         }
         synchronized (prismAccess) {
             delta.applyTo(taskPrism);