Fix leaked handle in Commit

Author: dahlbyk

LibGit2Sharp/Commit.cs

@@ -121,9 +121,10 @@ private IEnumerable<Commit> RetrieveParentsOfCommit(ObjectId oid)
 
                 for (uint i = 0; i < parentsCount; i++)
                 {
-                    GitObjectSafeHandle parentCommit;
-                    Ensure.Success(NativeMethods.git_commit_parent(out parentCommit, obj.ObjectPtr, i));
-                    yield return BuildFromPtr(parentCommit, ObjectIdOf(parentCommit), repo);
+                    using (var parentCommit = GetParentCommitHandle(i, obj))
+                    {
+                        yield return BuildFromPtr(parentCommit, ObjectIdOf(parentCommit), repo);
+                    }
                 }
             }
         }
@@ -146,6 +147,13 @@ internal static Commit BuildFromPtr(GitObjectSafeHandle obj, ObjectId id, Reposi
                        };
         }
 
+        private static GitObjectSafeHandle GetParentCommitHandle(uint i, ObjectSafeWrapper obj)
+        {
+            GitObjectSafeHandle parentCommit;
+            Ensure.Success(NativeMethods.git_commit_parent(out parentCommit, obj.ObjectPtr, i));
+            return parentCommit;
+        }
+
         private static string RetrieveEncodingOf(GitObjectSafeHandle obj)
         {
             string encoding = NativeMethods.git_commit_message_encoding(obj);