[gitg] Do not rely on last commit for parents

[Jesse van den Kieboom <jessevdk src gnome org>]

commit f058e4516fdf1f4280b7996d3666d992c78ea36e
Author: Jesse van den Kieboom <jessevdk gnome org>
Date:   Thu Aug 13 20:04:02 2015 +0200

    Do not rely on last commit for parents

 tests/support/repository.vala |   25 +++++++++++--------------
 1 files changed, 11 insertions(+), 14 deletions(-)
---
diff --git a/tests/support/repository.vala b/tests/support/repository.vala
index 6f6ca25..a7368aa 100644
--- a/tests/support/repository.vala
+++ b/tests/support/repository.vala
@@ -22,7 +22,6 @@ using Gitg.Test.Assert;
 class Gitg.Test.Repository : Gitg.Test.Test
 {
        protected Gitg.Repository? d_repository;
-       private Ggit.Commit? d_last_commit;
 
        struct File
        {
@@ -181,13 +180,22 @@ class Gitg.Test.Repository : Gitg.Test.Test
 
                Ggit.OId commitoid;
 
+               Ggit.Ref? head = null;
+               Ggit.Commit? parent = null;
+
+               try
+               {
+                       head = d_repository.get_head();
+                       parent = head.lookup() as Ggit.Commit;
+               } catch {}
+
                try
                {
                        Ggit.Commit[] parents;
 
-                       if (d_last_commit != null)
+                       if (parent != null)
                        {
-                               parents = new Ggit.Commit[] {d_last_commit};
+                               parents = new Ggit.Commit[] { parent };
                        }
                        else
                        {
@@ -207,15 +215,6 @@ class Gitg.Test.Repository : Gitg.Test.Test
                        assert_no_error(e);
                        return;
                }
-
-               try
-               {
-                       d_last_commit = d_repository.lookup<Ggit.Commit>(commitoid);
-               }
-               catch (GLib.Error e)
-               {
-                       assert_no_error(e);
-               }
        }
 
        protected void workdir_remove(string? filename, ...)
@@ -329,8 +328,6 @@ class Gitg.Test.Repository : Gitg.Test.Test
        {
                string wd;
 
-               d_last_commit = null;
-
                try
                {
                        wd = GLib.DirUtils.make_tmp("gitg-test-XXXXXX");