Fix "Failed to reindex changes"

Since ReindexAfterUpdate starts tasks asynchronously, it is possible for
a change that was once in the list of changes to get reindexed to no
longer exist. This could happen if a draft change existed at the moment
GetChanges was called and got deleted before db.get(id) is called. In
this case, it returns null and ChangeDataFactory tries to create a
ChangeData with a null Change which causes a ProvisionException.

This fix simply checks if the returned value is null and doesn't try to
reindex the change since it doesn't exist anymore.

Change-Id: I15dc1bde132a826a7ce1c7afef9242a7537ab894

1 files changed, 4 insertions, 1 deletions

diff --git a/gerrit-server/src/main/java/com/google/gerrit/server/index/ReindexAfterUpdate.java b/gerrit-server/src/main/java/com/google/gerrit/server/index/ReindexAfterUpdate.java
index 45b7c4da31..8ec82c3e5f 100644
--- a/gerrit-server/src/main/java/com/google/gerrit/server/index/ReindexAfterUpdate.java
+++ b/gerrit-server/src/main/java/com/google/gerrit/server/index/ReindexAfterUpdate.java
@@ -141,7 +141,10 @@ public class ReindexAfterUpdate implements GitReferenceUpdatedListener {
       // Reload change, as some time may have passed since GetChanges.
       ReviewDb db = ctx.getReviewDbProvider().get();
       Change c = db.changes().get(id);
-      indexerFactory.create(executor, indexes).index(db, c);
+      // The change might have been a draft and got deleted
+      if (c != null) {
+        indexerFactory.create(executor, indexes).index(db, c);
+      }
       return null;
     }