[gitg/vala] Properly resolve tag objects that point to commits

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

commit 6a2410aaddffd515745609c1e1213fe599653db8
Author: Jesse van den Kieboom <jesse vandenkieboom epfl ch>
Date:   Fri Jul 6 19:36:47 2012 +0200

    Properly resolve tag objects that point to commits

 libgitg/gitg-repository.vala      |   61 +++++++++++++++++++++++++++----------
 plugins/history/gitg-history.vala |   32 ++++++++++++++++----
 2 files changed, 71 insertions(+), 22 deletions(-)
---
diff --git a/libgitg/gitg-repository.vala b/libgitg/gitg-repository.vala
index 60a223d..5b72805 100644
--- a/libgitg/gitg-repository.vala
+++ b/libgitg/gitg-repository.vala
@@ -32,6 +32,28 @@ public class Repository : Ggit.Repository
 		((Initable)this).init(null);
 	}
 
+	private void ensure_refs_add(Ggit.OId? id, Gitg.Ref r)
+	{
+		if (id == null)
+		{
+			return;
+		}
+
+		unowned SList<Gitg.Ref> refs;
+
+		if (d_refs.lookup_extended(id, null, out refs))
+		{
+			refs.append(r);
+		}
+		else
+		{
+			SList<Gitg.Ref> nrefs = new SList<Gitg.Ref>();
+			nrefs.append(r);
+
+			d_refs.insert(id, (owned)nrefs);
+		}
+	}
+
 	private void ensure_refs()
 	{
 		if (d_refs != null)
@@ -53,27 +75,34 @@ public class Repository : Ggit.Repository
 				}
 				catch { return 0; }
 
-				if (r != null)
+				if (r == null)
+				{
+					return 0;
+				}
+
+				Ggit.OId? id = r.get_id();
+
+				if (id == null)
+				{
+					return 0;
+				}
+
+				ensure_refs_add(id, r);
+
+				// if it's a 'real' tag, then we are also going to store
+				// a ref to the underlying commit the tag points to
+				try
 				{
-					Ggit.OId? id = r.get_id();
+					var tag = lookup(id, typeof(Ggit.Tag)) as Ggit.Tag;
+
+					// get the target id
+					id = tag.get_target_id();
 
 					if (id != null)
 					{
-						unowned SList<Gitg.Ref> refs;
-
-						if (d_refs.lookup_extended(id, null, out refs))
-						{
-							refs.append(r);
-						}
-						else
-						{
-							SList<Gitg.Ref> nrefs = new SList<Gitg.Ref>();
-							nrefs.append(r);
-
-							d_refs.insert(id, (owned)nrefs);
-						}
+						ensure_refs_add(id, r);
 					}
-				}
+				} catch {}
 
 				return 0;
 			});
diff --git a/plugins/history/gitg-history.vala b/plugins/history/gitg-history.vala
index 10b0d2b..c840b5b 100644
--- a/plugins/history/gitg-history.vala
+++ b/plugins/history/gitg-history.vala
@@ -110,21 +110,41 @@ namespace GitgHistory
 			d_main = ret["scrolled_window_commit_list"] as Gtk.Widget;
 		}
 
-		private void update_walker(Ggit.Ref? head)
+		private void update_walker(Gitg.Ref? head)
 		{
-			Ggit.Ref? th = head;
+			Ggit.OId? id = null;
 
-			if (th == null && application.repository != null)
+			if (head != null && head.parsed_name.rtype == Gitg.RefType.TAG)
 			{
+				// See to resolve to the commit
 				try
 				{
-					th = application.repository.get_head();
+					var t = application.repository.lookup(head.get_id(), typeof(Ggit.Tag)) as Ggit.Tag;
+
+					id = t.get_target_id();
+				} catch {}
+			}
+			else if (head != null)
+			{
+				id = head.get_id();
+			}
+
+			if (id == null && application.repository != null)
+			{
+				try
+				{
+					Gitg.Ref? th = application.repository.get_head();
+
+					if (th != null)
+					{
+						id = th.get_id();
+					}
 				} catch {}
 			}
 
-			if (th != null)
+			if (id != null)
 			{
-				d_model.set_include(new Ggit.OId[] { th.get_id() });
+				d_model.set_include(new Ggit.OId[] { id });
 			}
 
 			d_model.reload();