From 0aec652e5f675f88d6b07a97ae5b5a1991da8f34 Mon Sep 17 00:00:00 2001
From: Hrvoje Hudoletnjak <hrvoje.hudoletnjak@gmail.com>
Date: Tue, 19 Aug 2014 23:44:42 +0100
Subject: [PATCH] Persistence store commit returns null fix, passing test
 added. Simulates pipeline pre-commit hook returning a false.

---
 .../OptimisticEventStreamTests.cs             | 23 +++++++++++++++++++
 src/NEventStore/OptimisticEventStream.cs      | 10 +++++---
 2 files changed, 30 insertions(+), 3 deletions(-)

diff --git a/src/NEventStore.Tests/OptimisticEventStreamTests.cs b/src/NEventStore.Tests/OptimisticEventStreamTests.cs
index 31c3c9cae..463f4f1a8 100644
--- a/src/NEventStore.Tests/OptimisticEventStreamTests.cs
+++ b/src/NEventStore.Tests/OptimisticEventStreamTests.cs
@@ -524,6 +524,29 @@ public void should_throw_an_exception_when_removing_from_the_uncommitted_collect
         {
             Catch.Exception(() => Stream.UncommittedEvents.Remove(null)).Should().BeOfType<NotSupportedException>();
         }
+    }
+
+    public class when_persistance_store_commit_returns_null : on_the_event_stream
+    {
+        protected override void Context()
+        {
+            // simulates pipeline pre-commit hook returning a false
+            A.CallTo(() => Persistence.Commit(A<CommitAttempt>.Ignored)).Returns(null);
+        }
+
+        protected override void Because()
+        {
+            Stream = new OptimisticEventStream(BucketId, StreamId, Persistence);
+            Stream.Add(new EventMessage() { Body = "body" });
+            Stream.CommitChanges(Guid.NewGuid());
+        }
+
+        [Fact]
+        public void should_not_contain_commited_events()
+        {
+            Stream.CommittedEvents.Count().Should().Be(0);
+        }
+
     }
 
     public abstract class on_the_event_stream : SpecificationBase, IUseFixture<FakeTimeFixture>
diff --git a/src/NEventStore/OptimisticEventStream.cs b/src/NEventStore/OptimisticEventStream.cs
index 66d4ed88c..7f8fc6a48 100644
--- a/src/NEventStore/OptimisticEventStream.cs
+++ b/src/NEventStore/OptimisticEventStream.cs
@@ -186,9 +186,13 @@ private void PersistChanges(Guid commitId)
             CommitAttempt attempt = BuildCommitAttempt(commitId);
 
             Logger.Debug(Resources.PersistingCommit, commitId, StreamId);
-            ICommit commit = _persistence.Commit(attempt);
-
-            PopulateStream(StreamRevision + 1, attempt.StreamRevision, new[] { commit });
+            ICommit commit = _persistence.Commit(attempt);
+
+            if (commit != null)
+            {
+                PopulateStream(StreamRevision + 1, attempt.StreamRevision, new[] {commit});
+            }
+
             ClearChanges();
         }