- Prevent adding your own errors to self.

- Prevents both duplication and modifying the list you are iterating,
  with the unpleasant ConcurrenModificationException.

1 files changed, 1 insertions, 0 deletions

diff --git a/container-search/src/main/java/com/yahoo/search/result/DefaultErrorHit.java b/container-search/src/main/java/com/yahoo/search/result/DefaultErrorHit.java
index 5fd41be0a54..fdd5c79adb6 100644
--- a/container-search/src/main/java/com/yahoo/search/result/DefaultErrorHit.java
+++ b/container-search/src/main/java/com/yahoo/search/result/DefaultErrorHit.java
@@ -75,6 +75,7 @@ public class DefaultErrorHit extends Hit implements ErrorHit, Cloneable {
 
     /** Add all errors from another error hit to this */
     public void addErrors(ErrorHit errorHit) {
+        if (this == errorHit) return;
         for (Iterator<? extends ErrorMessage> i = errorHit.errorIterator(); i.hasNext();) {
             addError(i.next());
         }