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*/

using System.Collections.Generic;
using NGit;
using NGit.Revwalk;
using NGit.Storage.File;
using Sharpen;

namespace NGit.Storage.File
{
	[NUnit.Framework.TestFixture]
	public class RefUpdateTest : SampleDataRepositoryTestCase
	{
		/// <exception cref="System.IO.IOException"></exception>
		private void WriteSymref(string src, string dst)
		{
			RefUpdate u = db.UpdateRef(src);
			switch (u.Link(dst))
			{
				case RefUpdate.Result.NEW:
				case RefUpdate.Result.FORCED:
				case RefUpdate.Result.NO_CHANGE:
				{
					break;
				}

				default:
				{
					NUnit.Framework.Assert.Fail("link " + src + " to " + dst);
					break;
				}
			}
		}

		/// <exception cref="System.IO.IOException"></exception>
		private RefUpdate UpdateRef(string name)
		{
			RefUpdate @ref = db.UpdateRef(name);
			@ref.SetNewObjectId(db.Resolve(Constants.HEAD));
			return @ref;
		}

		/// <exception cref="System.IO.IOException"></exception>
		private void Delete(RefUpdate @ref, RefUpdate.Result expected)
		{
			Delete(@ref, expected, true, true);
		}

		/// <exception cref="System.IO.IOException"></exception>
		private void Delete(RefUpdate @ref, RefUpdate.Result expected, bool exists, bool 
			removed)
		{
			NUnit.Framework.Assert.AreEqual(exists, db.GetAllRefs().ContainsKey(@ref.GetName(
				)));
			NUnit.Framework.Assert.AreEqual(expected, @ref.Delete());
			NUnit.Framework.Assert.AreEqual(!removed, db.GetAllRefs().ContainsKey(@ref.GetName
				()));
		}

		/// <exception cref="System.IO.IOException"></exception>
		[NUnit.Framework.Test]
		public virtual void TestNoCacheObjectIdSubclass()
		{
			string newRef = "refs/heads/abc";
			RefUpdate ru = UpdateRef(newRef);
			RefUpdateTest.SubclassedId newid = new RefUpdateTest.SubclassedId(ru.GetNewObjectId
				());
			ru.SetNewObjectId(newid);
			RefUpdate.Result update = ru.Update();
			NUnit.Framework.Assert.AreEqual(RefUpdate.Result.NEW, update);
			Ref r = db.GetAllRefs().Get(newRef);
			NUnit.Framework.Assert.IsNotNull(r);
			NUnit.Framework.Assert.AreEqual(newRef, r.GetName());
			NUnit.Framework.Assert.IsNotNull(r.GetObjectId());
			NUnit.Framework.Assert.AreNotSame(newid, r.GetObjectId());
			NUnit.Framework.Assert.AreSame(typeof(ObjectId), r.GetObjectId().GetType());
			NUnit.Framework.Assert.AreEqual(newid, r.GetObjectId());
			IList<ReflogEntry> reverseEntries1 = db.GetReflogReader("refs/heads/abc").GetReverseEntries
				();
			ReflogEntry entry1 = reverseEntries1[0];
			NUnit.Framework.Assert.AreEqual(1, reverseEntries1.Count);
			NUnit.Framework.Assert.AreEqual(ObjectId.ZeroId, entry1.GetOldId());
			NUnit.Framework.Assert.AreEqual(r.GetObjectId(), entry1.GetNewId());
			NUnit.Framework.Assert.AreEqual(new PersonIdent(db).ToString(), entry1.GetWho().ToString
				());
			NUnit.Framework.Assert.AreEqual(string.Empty, entry1.GetComment());
			IList<ReflogEntry> reverseEntries2 = db.GetReflogReader("HEAD").GetReverseEntries
				();
			NUnit.Framework.Assert.AreEqual(0, reverseEntries2.Count);
		}

		/// <exception cref="System.IO.IOException"></exception>
		[NUnit.Framework.Test]
		public virtual void TestNewNamespaceConflictWithLoosePrefixNameExists()
		{
			string newRef = "refs/heads/z";
			RefUpdate ru = UpdateRef(newRef);
			RefUpdate.Result update = ru.Update();
			NUnit.Framework.Assert.AreEqual(RefUpdate.Result.NEW, update);
			// end setup
			string newRef2 = "refs/heads/z/a";
			RefUpdate ru2 = UpdateRef(newRef2);
			RefUpdate.Result update2 = ru2.Update();
			NUnit.Framework.Assert.AreEqual(RefUpdate.Result.LOCK_FAILURE, update2);
			NUnit.Framework.Assert.AreEqual(1, db.GetReflogReader("refs/heads/z").GetReverseEntries
				().Count);
			NUnit.Framework.Assert.AreEqual(0, db.GetReflogReader("HEAD").GetReverseEntries()
				.Count);
		}

		/// <exception cref="System.IO.IOException"></exception>
		[NUnit.Framework.Test]
		public virtual void TestNewNamespaceConflictWithPackedPrefixNameExists()
		{
			string newRef = "refs/heads/master/x";
			RefUpdate ru = UpdateRef(newRef);
			RefUpdate.Result update = ru.Update();
			NUnit.Framework.Assert.AreEqual(RefUpdate.Result.LOCK_FAILURE, update);
			NUnit.Framework.Assert.IsNull(db.GetReflogReader("refs/heads/master/x"));
			NUnit.Framework.Assert.AreEqual(0, db.GetReflogReader("HEAD").GetReverseEntries()
				.Count);
		}

		/// <exception cref="System.IO.IOException"></exception>
		[NUnit.Framework.Test]
		public virtual void TestNewNamespaceConflictWithLoosePrefixOfExisting()
		{
			string newRef = "refs/heads/z/a";
			RefUpdate ru = UpdateRef(newRef);
			RefUpdate.Result update = ru.Update();
			NUnit.Framework.Assert.AreEqual(RefUpdate.Result.NEW, update);
			// end setup
			string newRef2 = "refs/heads/z";
			RefUpdate ru2 = UpdateRef(newRef2);
			RefUpdate.Result update2 = ru2.Update();
			NUnit.Framework.Assert.AreEqual(RefUpdate.Result.LOCK_FAILURE, update2);
			NUnit.Framework.Assert.AreEqual(1, db.GetReflogReader("refs/heads/z/a").GetReverseEntries
				().Count);
			NUnit.Framework.Assert.IsNull(db.GetReflogReader("refs/heads/z"));
			NUnit.Framework.Assert.AreEqual(0, db.GetReflogReader("HEAD").GetReverseEntries()
				.Count);
		}

		/// <exception cref="System.IO.IOException"></exception>
		[NUnit.Framework.Test]
		public virtual void TestNewNamespaceConflictWithPackedPrefixOfExisting()
		{
			string newRef = "refs/heads/prefix";
			RefUpdate ru = UpdateRef(newRef);
			RefUpdate.Result update = ru.Update();
			NUnit.Framework.Assert.AreEqual(RefUpdate.Result.LOCK_FAILURE, update);
			NUnit.Framework.Assert.IsNull(db.GetReflogReader("refs/heads/prefix"));
			NUnit.Framework.Assert.AreEqual(0, db.GetReflogReader("HEAD").GetReverseEntries()
				.Count);
		}

		/// <summary>Delete a ref that is pointed to by HEAD</summary>
		/// <exception cref="System.IO.IOException">System.IO.IOException</exception>
		[NUnit.Framework.Test]
		public virtual void TestDeleteHEADreferencedRef()
		{
			ObjectId pid = db.Resolve("refs/heads/master^");
			RefUpdate updateRef = db.UpdateRef("refs/heads/master");
			updateRef.SetNewObjectId(pid);
			updateRef.SetForceUpdate(true);
			RefUpdate.Result update = updateRef.Update();
			NUnit.Framework.Assert.AreEqual(RefUpdate.Result.FORCED, update);
			// internal
			RefUpdate updateRef2 = db.UpdateRef("refs/heads/master");
			RefUpdate.Result delete = updateRef2.Delete();
			NUnit.Framework.Assert.AreEqual(RefUpdate.Result.REJECTED_CURRENT_BRANCH, delete);
			NUnit.Framework.Assert.AreEqual(pid, db.Resolve("refs/heads/master"));
			NUnit.Framework.Assert.AreEqual(1, db.GetReflogReader("refs/heads/master").GetReverseEntries
				().Count);
			NUnit.Framework.Assert.AreEqual(0, db.GetReflogReader("HEAD").GetReverseEntries()
				.Count);
		}

		/// <exception cref="System.IO.IOException"></exception>
		[NUnit.Framework.Test]
		public virtual void TestLooseDelete()
		{
			string newRef = "refs/heads/abc";
			RefUpdate @ref = UpdateRef(newRef);
			@ref.Update();
			// create loose ref
			@ref = UpdateRef(newRef);
			// refresh
			Delete(@ref, RefUpdate.Result.NO_CHANGE);
			NUnit.Framework.Assert.IsNull(db.GetReflogReader("refs/heads/abc"));
		}

		/// <exception cref="System.IO.IOException"></exception>
		[NUnit.Framework.Test]
		public virtual void TestDeleteHead()
		{
			RefUpdate @ref = UpdateRef(Constants.HEAD);
			Delete(@ref, RefUpdate.Result.REJECTED_CURRENT_BRANCH, true, false);
			NUnit.Framework.Assert.AreEqual(0, db.GetReflogReader("refs/heads/master").GetReverseEntries
				().Count);
			NUnit.Framework.Assert.AreEqual(0, db.GetReflogReader("HEAD").GetReverseEntries()
				.Count);
		}

		/// <summary>
		/// Delete a loose ref and make sure the directory in refs is deleted too,
		/// and the reflog dir too
		/// </summary>
		/// <exception cref="System.IO.IOException">System.IO.IOException</exception>
		[NUnit.Framework.Test]
		public virtual void TestDeleteLooseAndItsDirectory()
		{
			ObjectId pid = db.Resolve("refs/heads/c^");
			RefUpdate updateRef = db.UpdateRef("refs/heads/z/c");
			updateRef.SetNewObjectId(pid);
			updateRef.SetForceUpdate(true);
			updateRef.SetRefLogMessage("new test ref", false);
			RefUpdate.Result update = updateRef.Update();
			NUnit.Framework.Assert.AreEqual(RefUpdate.Result.NEW, update);
			// internal
			NUnit.Framework.Assert.IsTrue(new FilePath(db.Directory, Constants.R_HEADS + "z")
				.Exists());
			NUnit.Framework.Assert.IsTrue(new FilePath(db.Directory, "logs/refs/heads/z").Exists
				());
			// The real test here
			RefUpdate updateRef2 = db.UpdateRef("refs/heads/z/c");
			updateRef2.SetForceUpdate(true);
			RefUpdate.Result delete = updateRef2.Delete();
			NUnit.Framework.Assert.AreEqual(RefUpdate.Result.FORCED, delete);
			NUnit.Framework.Assert.IsNull(db.Resolve("refs/heads/z/c"));
			NUnit.Framework.Assert.IsFalse(new FilePath(db.Directory, Constants.R_HEADS + "z"
				).Exists());
			NUnit.Framework.Assert.IsFalse(new FilePath(db.Directory, "logs/refs/heads/z").Exists
				());
		}

		/// <exception cref="System.IO.IOException"></exception>
		[NUnit.Framework.Test]
		public virtual void TestDeleteNotFound()
		{
			RefUpdate @ref = UpdateRef("refs/heads/xyz");
			Delete(@ref, RefUpdate.Result.NEW, false, true);
		}

		/// <exception cref="System.IO.IOException"></exception>
		[NUnit.Framework.Test]
		public virtual void TestDeleteFastForward()
		{
			RefUpdate @ref = UpdateRef("refs/heads/a");
			Delete(@ref, RefUpdate.Result.FAST_FORWARD);
		}

		/// <exception cref="System.IO.IOException"></exception>
		[NUnit.Framework.Test]
		public virtual void TestDeleteForce()
		{
			RefUpdate @ref = db.UpdateRef("refs/heads/b");
			@ref.SetNewObjectId(db.Resolve("refs/heads/a"));
			Delete(@ref, RefUpdate.Result.REJECTED, true, false);
			@ref.SetForceUpdate(true);
			Delete(@ref, RefUpdate.Result.FORCED);
		}

		[NUnit.Framework.Test]
		public virtual void TestRefKeySameAsName()
		{
			IDictionary<string, Ref> allRefs = db.GetAllRefs();
			foreach (KeyValuePair<string, Ref> e in allRefs.EntrySet())
			{
				NUnit.Framework.Assert.AreEqual(e.Key, e.Value.GetName());
			}
		}

		/// <summary>Try modify a ref forward, fast forward</summary>
		/// <exception cref="System.IO.IOException">System.IO.IOException</exception>
		[NUnit.Framework.Test]
		public virtual void TestUpdateRefForward()
		{
			ObjectId ppid = db.Resolve("refs/heads/master^");
			ObjectId pid = db.Resolve("refs/heads/master");
			RefUpdate updateRef = db.UpdateRef("refs/heads/master");
			updateRef.SetNewObjectId(ppid);
			updateRef.SetForceUpdate(true);
			RefUpdate.Result update = updateRef.Update();
			NUnit.Framework.Assert.AreEqual(RefUpdate.Result.FORCED, update);
			NUnit.Framework.Assert.AreEqual(ppid, db.Resolve("refs/heads/master"));
			// real test
			RefUpdate updateRef2 = db.UpdateRef("refs/heads/master");
			updateRef2.SetNewObjectId(pid);
			RefUpdate.Result update2 = updateRef2.Update();
			NUnit.Framework.Assert.AreEqual(RefUpdate.Result.FAST_FORWARD, update2);
			NUnit.Framework.Assert.AreEqual(pid, db.Resolve("refs/heads/master"));
		}

		/// <summary>Update the HEAD ref.</summary>
		/// <remarks>Update the HEAD ref. Only it should be changed, not what it points to.</remarks>
		/// <exception cref="System.Exception">System.Exception</exception>
		[NUnit.Framework.Test]
		public virtual void TestUpdateRefDetached()
		{
			ObjectId pid = db.Resolve("refs/heads/master");
			ObjectId ppid = db.Resolve("refs/heads/master^");
			RefUpdate updateRef = db.UpdateRef("HEAD", true);
			updateRef.SetForceUpdate(true);
			updateRef.SetNewObjectId(ppid);
			RefUpdate.Result update = updateRef.Update();
			NUnit.Framework.Assert.AreEqual(RefUpdate.Result.FORCED, update);
			NUnit.Framework.Assert.AreEqual(ppid, db.Resolve("HEAD"));
			Ref @ref = db.GetRef("HEAD");
			NUnit.Framework.Assert.AreEqual("HEAD", @ref.GetName());
			NUnit.Framework.Assert.IsTrue(!@ref.IsSymbolic(), "is detached");
			// the branch HEAD referred to is left untouched
			NUnit.Framework.Assert.AreEqual(pid, db.Resolve("refs/heads/master"));
			ReflogReader reflogReader = new ReflogReader(db, "HEAD");
			ReflogEntry e = reflogReader.GetReverseEntries()[0];
			NUnit.Framework.Assert.AreEqual(pid, e.GetOldId());
			NUnit.Framework.Assert.AreEqual(ppid, e.GetNewId());
			NUnit.Framework.Assert.AreEqual("GIT_COMMITTER_EMAIL", e.GetWho().GetEmailAddress
				());
			NUnit.Framework.Assert.AreEqual("GIT_COMMITTER_NAME", e.GetWho().GetName());
			NUnit.Framework.Assert.AreEqual(1250379778000L, e.GetWho().GetWhen().GetTime());
		}

		/// <summary>Update the HEAD ref when the referenced branch is unborn</summary>
		/// <exception cref="System.Exception">System.Exception</exception>
		[NUnit.Framework.Test]
		public virtual void TestUpdateRefDetachedUnbornHead()
		{
			ObjectId ppid = db.Resolve("refs/heads/master^");
			WriteSymref("HEAD", "refs/heads/unborn");
			RefUpdate updateRef = db.UpdateRef("HEAD", true);
			updateRef.SetForceUpdate(true);
			updateRef.SetNewObjectId(ppid);
			RefUpdate.Result update = updateRef.Update();
			NUnit.Framework.Assert.AreEqual(RefUpdate.Result.NEW, update);
			NUnit.Framework.Assert.AreEqual(ppid, db.Resolve("HEAD"));
			Ref @ref = db.GetRef("HEAD");
			NUnit.Framework.Assert.AreEqual("HEAD", @ref.GetName());
			NUnit.Framework.Assert.IsTrue(!@ref.IsSymbolic(), "is detached");
			// the branch HEAD referred to is left untouched
			NUnit.Framework.Assert.IsNull(db.Resolve("refs/heads/unborn"));
			ReflogReader reflogReader = new ReflogReader(db, "HEAD");
			ReflogEntry e = reflogReader.GetReverseEntries()[0];
			NUnit.Framework.Assert.AreEqual(ObjectId.ZeroId, e.GetOldId());
			NUnit.Framework.Assert.AreEqual(ppid, e.GetNewId());
			NUnit.Framework.Assert.AreEqual("GIT_COMMITTER_EMAIL", e.GetWho().GetEmailAddress
				());
			NUnit.Framework.Assert.AreEqual("GIT_COMMITTER_NAME", e.GetWho().GetName());
			NUnit.Framework.Assert.AreEqual(1250379778000L, e.GetWho().GetWhen().GetTime());
		}

		/// <summary>Delete a ref that exists both as packed and loose.</summary>
		/// <remarks>
		/// Delete a ref that exists both as packed and loose. Make sure the ref
		/// cannot be resolved after delete.
		/// </remarks>
		/// <exception cref="System.IO.IOException">System.IO.IOException</exception>
		[NUnit.Framework.Test]
		public virtual void TestDeleteLoosePacked()
		{
			ObjectId pid = db.Resolve("refs/heads/c^");
			RefUpdate updateRef = db.UpdateRef("refs/heads/c");
			updateRef.SetNewObjectId(pid);
			updateRef.SetForceUpdate(true);
			RefUpdate.Result update = updateRef.Update();
			NUnit.Framework.Assert.AreEqual(RefUpdate.Result.FORCED, update);
			// internal
			// The real test here
			RefUpdate updateRef2 = db.UpdateRef("refs/heads/c");
			updateRef2.SetForceUpdate(true);
			RefUpdate.Result delete = updateRef2.Delete();
			NUnit.Framework.Assert.AreEqual(RefUpdate.Result.FORCED, delete);
			NUnit.Framework.Assert.IsNull(db.Resolve("refs/heads/c"));
		}

		/// <summary>Try modify a ref to same</summary>
		/// <exception cref="System.IO.IOException">System.IO.IOException</exception>
		[NUnit.Framework.Test]
		public virtual void TestUpdateRefNoChange()
		{
			ObjectId pid = db.Resolve("refs/heads/master");
			RefUpdate updateRef = db.UpdateRef("refs/heads/master");
			updateRef.SetNewObjectId(pid);
			RefUpdate.Result update = updateRef.Update();
			NUnit.Framework.Assert.AreEqual(RefUpdate.Result.NO_CHANGE, update);
			NUnit.Framework.Assert.AreEqual(pid, db.Resolve("refs/heads/master"));
		}

		/// <summary>
		/// Test case originating from
		/// <a href="http://bugs.eclipse.org/285991">bug 285991</a>
		/// Make sure the in memory cache is updated properly after
		/// update of symref.
		/// </summary>
		/// <remarks>
		/// Test case originating from
		/// <a href="http://bugs.eclipse.org/285991">bug 285991</a>
		/// Make sure the in memory cache is updated properly after
		/// update of symref. This one did not fail because the
		/// ref was packed due to implementation issues.
		/// </remarks>
		/// <exception cref="System.Exception">System.Exception</exception>
		[NUnit.Framework.Test]
		public virtual void TestRefsCacheAfterUpdate()
		{
			// Do not use the defalt repo for this case.
			IDictionary<string, Ref> allRefs = db.GetAllRefs();
			ObjectId oldValue = db.Resolve("HEAD");
			ObjectId newValue = db.Resolve("HEAD^");
			// first make HEAD refer to loose ref
			RefUpdate updateRef = db.UpdateRef(Constants.HEAD);
			updateRef.SetForceUpdate(true);
			updateRef.SetNewObjectId(newValue);
			RefUpdate.Result update = updateRef.Update();
			NUnit.Framework.Assert.AreEqual(RefUpdate.Result.FORCED, update);
			// now update that ref
			updateRef = db.UpdateRef(Constants.HEAD);
			updateRef.SetForceUpdate(true);
			updateRef.SetNewObjectId(oldValue);
			update = updateRef.Update();
			NUnit.Framework.Assert.AreEqual(RefUpdate.Result.FAST_FORWARD, update);
			allRefs = db.GetAllRefs();
			Ref master = allRefs.Get("refs/heads/master");
			Ref head = allRefs.Get("HEAD");
			NUnit.Framework.Assert.AreEqual("refs/heads/master", master.GetName());
			NUnit.Framework.Assert.AreEqual("HEAD", head.GetName());
			NUnit.Framework.Assert.IsTrue(head.IsSymbolic(), "is symbolic reference");
			NUnit.Framework.Assert.AreSame(master, head.GetTarget());
		}

		/// <summary>
		/// Test case originating from
		/// <a href="http://bugs.eclipse.org/285991">bug 285991</a>
		/// Make sure the in memory cache is updated properly after
		/// update of symref.
		/// </summary>
		/// <remarks>
		/// Test case originating from
		/// <a href="http://bugs.eclipse.org/285991">bug 285991</a>
		/// Make sure the in memory cache is updated properly after
		/// update of symref.
		/// </remarks>
		/// <exception cref="System.Exception">System.Exception</exception>
		[NUnit.Framework.Test]
		public virtual void TestRefsCacheAfterUpdateLooseOnly()
		{
			// Do not use the defalt repo for this case.
			IDictionary<string, Ref> allRefs = db.GetAllRefs();
			ObjectId oldValue = db.Resolve("HEAD");
			WriteSymref(Constants.HEAD, "refs/heads/newref");
			RefUpdate updateRef = db.UpdateRef(Constants.HEAD);
			updateRef.SetForceUpdate(true);
			updateRef.SetNewObjectId(oldValue);
			RefUpdate.Result update = updateRef.Update();
			NUnit.Framework.Assert.AreEqual(RefUpdate.Result.NEW, update);
			allRefs = db.GetAllRefs();
			Ref head = allRefs.Get("HEAD");
			Ref newref = allRefs.Get("refs/heads/newref");
			NUnit.Framework.Assert.AreEqual("refs/heads/newref", newref.GetName());
			NUnit.Framework.Assert.AreEqual("HEAD", head.GetName());
			NUnit.Framework.Assert.IsTrue(head.IsSymbolic(), "is symbolic reference");
			NUnit.Framework.Assert.AreSame(newref, head.GetTarget());
		}

		/// <summary>Try modify a ref, but get wrong expected old value</summary>
		/// <exception cref="System.IO.IOException">System.IO.IOException</exception>
		[NUnit.Framework.Test]
		public virtual void TestUpdateRefLockFailureWrongOldValue()
		{
			ObjectId pid = db.Resolve("refs/heads/master");
			RefUpdate updateRef = db.UpdateRef("refs/heads/master");
			updateRef.SetNewObjectId(pid);
			updateRef.SetExpectedOldObjectId(db.Resolve("refs/heads/master^"));
			RefUpdate.Result update = updateRef.Update();
			NUnit.Framework.Assert.AreEqual(RefUpdate.Result.LOCK_FAILURE, update);
			NUnit.Framework.Assert.AreEqual(pid, db.Resolve("refs/heads/master"));
		}

		/// <summary>Try modify a ref forward, fast forward, checking old value first</summary>
		/// <exception cref="System.IO.IOException">System.IO.IOException</exception>
		[NUnit.Framework.Test]
		public virtual void TestUpdateRefForwardWithCheck1()
		{
			ObjectId ppid = db.Resolve("refs/heads/master^");
			ObjectId pid = db.Resolve("refs/heads/master");
			RefUpdate updateRef = db.UpdateRef("refs/heads/master");
			updateRef.SetNewObjectId(ppid);
			updateRef.SetForceUpdate(true);
			RefUpdate.Result update = updateRef.Update();
			NUnit.Framework.Assert.AreEqual(RefUpdate.Result.FORCED, update);
			NUnit.Framework.Assert.AreEqual(ppid, db.Resolve("refs/heads/master"));
			// real test
			RefUpdate updateRef2 = db.UpdateRef("refs/heads/master");
			updateRef2.SetExpectedOldObjectId(ppid);
			updateRef2.SetNewObjectId(pid);
			RefUpdate.Result update2 = updateRef2.Update();
			NUnit.Framework.Assert.AreEqual(RefUpdate.Result.FAST_FORWARD, update2);
			NUnit.Framework.Assert.AreEqual(pid, db.Resolve("refs/heads/master"));
		}

		/// <summary>Try modify a ref forward, fast forward, checking old commit first</summary>
		/// <exception cref="System.IO.IOException">System.IO.IOException</exception>
		[NUnit.Framework.Test]
		public virtual void TestUpdateRefForwardWithCheck2()
		{
			ObjectId ppid = db.Resolve("refs/heads/master^");
			ObjectId pid = db.Resolve("refs/heads/master");
			RefUpdate updateRef = db.UpdateRef("refs/heads/master");
			updateRef.SetNewObjectId(ppid);
			updateRef.SetForceUpdate(true);
			RefUpdate.Result update = updateRef.Update();
			NUnit.Framework.Assert.AreEqual(RefUpdate.Result.FORCED, update);
			NUnit.Framework.Assert.AreEqual(ppid, db.Resolve("refs/heads/master"));
			// real test
			RevCommit old = new RevWalk(db).ParseCommit(ppid);
			RefUpdate updateRef2 = db.UpdateRef("refs/heads/master");
			updateRef2.SetExpectedOldObjectId(old);
			updateRef2.SetNewObjectId(pid);
			RefUpdate.Result update2 = updateRef2.Update();
			NUnit.Framework.Assert.AreEqual(RefUpdate.Result.FAST_FORWARD, update2);
			NUnit.Framework.Assert.AreEqual(pid, db.Resolve("refs/heads/master"));
		}

		/// <summary>Try modify a ref that is locked</summary>
		/// <exception cref="System.IO.IOException">System.IO.IOException</exception>
		[NUnit.Framework.Test]
		public virtual void TestUpdateRefLockFailureLocked()
		{
			ObjectId opid = db.Resolve("refs/heads/master");
			ObjectId pid = db.Resolve("refs/heads/master^");
			RefUpdate updateRef = db.UpdateRef("refs/heads/master");
			updateRef.SetNewObjectId(pid);
			LockFile lockFile1 = new LockFile(new FilePath(db.Directory, "refs/heads/master")
				, db.FileSystem);
			try
			{
				NUnit.Framework.Assert.IsTrue(lockFile1.Lock());
				// precondition to test
				RefUpdate.Result update = updateRef.Update();
				NUnit.Framework.Assert.AreEqual(RefUpdate.Result.LOCK_FAILURE, update);
				NUnit.Framework.Assert.AreEqual(opid, db.Resolve("refs/heads/master"));
				LockFile lockFile2 = new LockFile(new FilePath(db.Directory, "refs/heads/master")
					, db.FileSystem);
				NUnit.Framework.Assert.IsFalse(lockFile2.Lock());
			}
			finally
			{
				// was locked, still is
				lockFile1.Unlock();
			}
		}

		/// <summary>Try to delete a ref.</summary>
		/// <remarks>Try to delete a ref. Delete requires force.</remarks>
		/// <exception cref="System.IO.IOException">System.IO.IOException</exception>
		[NUnit.Framework.Test]
		public virtual void TestDeleteLoosePackedRejected()
		{
			ObjectId pid = db.Resolve("refs/heads/c^");
			ObjectId oldpid = db.Resolve("refs/heads/c");
			RefUpdate updateRef = db.UpdateRef("refs/heads/c");
			updateRef.SetNewObjectId(pid);
			RefUpdate.Result update = updateRef.Update();
			NUnit.Framework.Assert.AreEqual(RefUpdate.Result.REJECTED, update);
			NUnit.Framework.Assert.AreEqual(oldpid, db.Resolve("refs/heads/c"));
		}

		/// <exception cref="System.IO.IOException"></exception>
		[NUnit.Framework.Test]
		public virtual void TestRenameBranchNoPreviousLog()
		{
			NUnit.Framework.Assert.IsFalse(new FilePath(db.Directory, "logs/refs/heads/b").Exists
				(), "precondition, no log on old branchg");
			ObjectId rb = db.Resolve("refs/heads/b");
			ObjectId oldHead = db.Resolve(Constants.HEAD);
			NUnit.Framework.Assert.IsFalse(rb.Equals(oldHead));
			// assumption for this test
			RefRename renameRef = db.RenameRef("refs/heads/b", "refs/heads/new/name");
			RefUpdate.Result result = renameRef.Rename();
			NUnit.Framework.Assert.AreEqual(RefUpdate.Result.RENAMED, result);
			NUnit.Framework.Assert.AreEqual(rb, db.Resolve("refs/heads/new/name"));
			NUnit.Framework.Assert.IsNull(db.Resolve("refs/heads/b"));
			NUnit.Framework.Assert.AreEqual(1, db.GetReflogReader("new/name").GetReverseEntries
				().Count);
			NUnit.Framework.Assert.AreEqual("Branch: renamed b to new/name", db.GetReflogReader
				("new/name").GetLastEntry().GetComment());
			NUnit.Framework.Assert.IsFalse(new FilePath(db.Directory, "logs/refs/heads/b").Exists
				());
			NUnit.Framework.Assert.AreEqual(oldHead, db.Resolve(Constants.HEAD));
		}

		// unchanged
		/// <exception cref="System.IO.IOException"></exception>
		[NUnit.Framework.Test]
		public virtual void TestRenameBranchHasPreviousLog()
		{
			ObjectId rb = db.Resolve("refs/heads/b");
			ObjectId oldHead = db.Resolve(Constants.HEAD);
			NUnit.Framework.Assert.IsFalse(rb.Equals(oldHead), "precondition for this test, branch b != HEAD"
				);
			WriteReflog(db, rb, "Just a message", "refs/heads/b");
			NUnit.Framework.Assert.IsTrue(new FilePath(db.Directory, "logs/refs/heads/b").Exists
				(), "log on old branch");
			RefRename renameRef = db.RenameRef("refs/heads/b", "refs/heads/new/name");
			RefUpdate.Result result = renameRef.Rename();
			NUnit.Framework.Assert.AreEqual(RefUpdate.Result.RENAMED, result);
			NUnit.Framework.Assert.AreEqual(rb, db.Resolve("refs/heads/new/name"));
			NUnit.Framework.Assert.IsNull(db.Resolve("refs/heads/b"));
			NUnit.Framework.Assert.AreEqual(2, db.GetReflogReader("new/name").GetReverseEntries
				().Count);
			NUnit.Framework.Assert.AreEqual("Branch: renamed b to new/name", db.GetReflogReader
				("new/name").GetLastEntry().GetComment());
			NUnit.Framework.Assert.AreEqual("Just a message", db.GetReflogReader("new/name").
				GetReverseEntries()[1].GetComment());
			NUnit.Framework.Assert.IsFalse(new FilePath(db.Directory, "logs/refs/heads/b").Exists
				());
			NUnit.Framework.Assert.AreEqual(oldHead, db.Resolve(Constants.HEAD));
		}

		// unchanged
		/// <exception cref="System.IO.IOException"></exception>
		[NUnit.Framework.Test]
		public virtual void TestRenameCurrentBranch()
		{
			ObjectId rb = db.Resolve("refs/heads/b");
			WriteSymref(Constants.HEAD, "refs/heads/b");
			ObjectId oldHead = db.Resolve(Constants.HEAD);
			NUnit.Framework.Assert.IsTrue(rb.Equals(oldHead), "internal test condition, b == HEAD"
				);
			WriteReflog(db, rb, "Just a message", "refs/heads/b");
			NUnit.Framework.Assert.IsTrue(new FilePath(db.Directory, "logs/refs/heads/b").Exists
				(), "log on old branch");
			RefRename renameRef = db.RenameRef("refs/heads/b", "refs/heads/new/name");
			RefUpdate.Result result = renameRef.Rename();
			NUnit.Framework.Assert.AreEqual(RefUpdate.Result.RENAMED, result);
			NUnit.Framework.Assert.AreEqual(rb, db.Resolve("refs/heads/new/name"));
			NUnit.Framework.Assert.IsNull(db.Resolve("refs/heads/b"));
			NUnit.Framework.Assert.AreEqual("Branch: renamed b to new/name", db.GetReflogReader
				("new/name").GetLastEntry().GetComment());
			NUnit.Framework.Assert.IsFalse(new FilePath(db.Directory, "logs/refs/heads/b").Exists
				());
			NUnit.Framework.Assert.AreEqual(rb, db.Resolve(Constants.HEAD));
			NUnit.Framework.Assert.AreEqual(2, db.GetReflogReader("new/name").GetReverseEntries
				().Count);
			NUnit.Framework.Assert.AreEqual("Branch: renamed b to new/name", db.GetReflogReader
				("new/name").GetReverseEntries()[0].GetComment());
			NUnit.Framework.Assert.AreEqual("Just a message", db.GetReflogReader("new/name").
				GetReverseEntries()[1].GetComment());
		}

		/// <exception cref="System.IO.IOException"></exception>
		[NUnit.Framework.Test]
		public virtual void TestRenameBranchAlsoInPack()
		{
			ObjectId rb = db.Resolve("refs/heads/b");
			ObjectId rb2 = db.Resolve("refs/heads/b~1");
			NUnit.Framework.Assert.AreEqual(RefStorage.PACKED, db.GetRef("refs/heads/b").GetStorage
				());
			RefUpdate updateRef = db.UpdateRef("refs/heads/b");
			updateRef.SetNewObjectId(rb2);
			updateRef.SetForceUpdate(true);
			RefUpdate.Result update = updateRef.Update();
			NUnit.Framework.Assert.AreEqual(RefUpdate.Result.FORCED, update, "internal check new ref is loose"
				);
			NUnit.Framework.Assert.AreEqual(RefStorage.LOOSE, db.GetRef("refs/heads/b").GetStorage
				());
			WriteReflog(db, rb, "Just a message", "refs/heads/b");
			NUnit.Framework.Assert.IsTrue(new FilePath(db.Directory, "logs/refs/heads/b").Exists
				(), "log on old branch");
			RefRename renameRef = db.RenameRef("refs/heads/b", "refs/heads/new/name");
			RefUpdate.Result result = renameRef.Rename();
			NUnit.Framework.Assert.AreEqual(RefUpdate.Result.RENAMED, result);
			NUnit.Framework.Assert.AreEqual(rb2, db.Resolve("refs/heads/new/name"));
			NUnit.Framework.Assert.IsNull(db.Resolve("refs/heads/b"));
			NUnit.Framework.Assert.AreEqual("Branch: renamed b to new/name", db.GetReflogReader
				("new/name").GetLastEntry().GetComment());
			NUnit.Framework.Assert.AreEqual(3, db.GetReflogReader("refs/heads/new/name").GetReverseEntries
				().Count);
			NUnit.Framework.Assert.AreEqual("Branch: renamed b to new/name", db.GetReflogReader
				("refs/heads/new/name").GetReverseEntries()[0].GetComment());
			NUnit.Framework.Assert.AreEqual(0, db.GetReflogReader("HEAD").GetReverseEntries()
				.Count);
			// make sure b's log file is gone too.
			NUnit.Framework.Assert.IsFalse(new FilePath(db.Directory, "logs/refs/heads/b").Exists
				());
			// Create new Repository instance, to reread caches and make sure our
			// assumptions are persistent.
			Repository ndb = new FileRepository(db.Directory);
			NUnit.Framework.Assert.AreEqual(rb2, ndb.Resolve("refs/heads/new/name"));
			NUnit.Framework.Assert.IsNull(ndb.Resolve("refs/heads/b"));
		}

		/// <exception cref="System.IO.IOException"></exception>
		public virtual void TryRenameWhenLocked(string toLock, string fromName, string toName
			, string headPointsTo)
		{
			// setup
			WriteSymref(Constants.HEAD, headPointsTo);
			ObjectId oldfromId = db.Resolve(fromName);
			ObjectId oldHeadId = db.Resolve(Constants.HEAD);
			WriteReflog(db, oldfromId, "Just a message", fromName);
			IList<ReflogEntry> oldFromLog = db.GetReflogReader(fromName).GetReverseEntries();
			IList<ReflogEntry> oldHeadLog = oldHeadId != null ? db.GetReflogReader(Constants.
				HEAD).GetReverseEntries() : null;
			NUnit.Framework.Assert.IsTrue(new FilePath(db.Directory, "logs/" + fromName).Exists
				(), "internal check, we have a log");
			// "someone" has branch X locked
			LockFile lockFile = new LockFile(new FilePath(db.Directory, toLock), db.FileSystem
				);
			try
			{
				NUnit.Framework.Assert.IsTrue(lockFile.Lock());
				// Now this is our test
				RefRename renameRef = db.RenameRef(fromName, toName);
				RefUpdate.Result result = renameRef.Rename();
				NUnit.Framework.Assert.AreEqual(RefUpdate.Result.LOCK_FAILURE, result);
				// Check that the involved refs are the same despite the failure
				AssertExists(false, toName);
				if (!toLock.Equals(toName))
				{
					AssertExists(false, toName + ".lock");
				}
				AssertExists(true, toLock + ".lock");
				if (!toLock.Equals(fromName))
				{
					AssertExists(false, "logs/" + fromName + ".lock");
				}
				AssertExists(false, "logs/" + toName + ".lock");
				NUnit.Framework.Assert.AreEqual(oldHeadId, db.Resolve(Constants.HEAD));
				NUnit.Framework.Assert.AreEqual(oldfromId, db.Resolve(fromName));
				NUnit.Framework.Assert.IsNull(db.Resolve(toName));
				NUnit.Framework.Assert.AreEqual(oldFromLog.ToString(), db.GetReflogReader(fromName
					).GetReverseEntries().ToString());
				if (oldHeadId != null)
				{
					NUnit.Framework.Assert.AreEqual(oldHeadLog.ToString(), db.GetReflogReader(Constants
						.HEAD).GetReverseEntries().ToString());
				}
			}
			finally
			{
				lockFile.Unlock();
			}
		}

		private void AssertExists(bool positive, string toName)
		{
			NUnit.Framework.Assert.AreEqual(positive, new FilePath(db.Directory, toName).Exists
				(), toName + (positive ? " " : " does not ") + "exist");
		}

		/// <exception cref="System.IO.IOException"></exception>
		[NUnit.Framework.Test]
		public virtual void TestRenameBranchCannotLockAFileHEADisFromLockHEAD()
		{
			TryRenameWhenLocked("HEAD", "refs/heads/b", "refs/heads/new/name", "refs/heads/b"
				);
		}

		/// <exception cref="System.IO.IOException"></exception>
		[NUnit.Framework.Test]
		public virtual void TestRenameBranchCannotLockAFileHEADisFromLockFrom()
		{
			TryRenameWhenLocked("refs/heads/b", "refs/heads/b", "refs/heads/new/name", "refs/heads/b"
				);
		}

		/// <exception cref="System.IO.IOException"></exception>
		[NUnit.Framework.Test]
		public virtual void TestRenameBranchCannotLockAFileHEADisFromLockTo()
		{
			TryRenameWhenLocked("refs/heads/new/name", "refs/heads/b", "refs/heads/new/name", 
				"refs/heads/b");
		}

		/// <exception cref="System.IO.IOException"></exception>
		[NUnit.Framework.Test]
		public virtual void TestRenameBranchCannotLockAFileHEADisToLockFrom()
		{
			TryRenameWhenLocked("refs/heads/b", "refs/heads/b", "refs/heads/new/name", "refs/heads/new/name"
				);
		}

		/// <exception cref="System.IO.IOException"></exception>
		[NUnit.Framework.Test]
		public virtual void TestRenameBranchCannotLockAFileHEADisToLockTo()
		{
			TryRenameWhenLocked("refs/heads/new/name", "refs/heads/b", "refs/heads/new/name", 
				"refs/heads/new/name");
		}

		/// <exception cref="System.IO.IOException"></exception>
		[NUnit.Framework.Test]
		public virtual void TestRenameBranchCannotLockAFileHEADisOtherLockFrom()
		{
			TryRenameWhenLocked("refs/heads/b", "refs/heads/b", "refs/heads/new/name", "refs/heads/a"
				);
		}

		/// <exception cref="System.IO.IOException"></exception>
		[NUnit.Framework.Test]
		public virtual void TestRenameBranchCannotLockAFileHEADisOtherLockTo()
		{
			TryRenameWhenLocked("refs/heads/new/name", "refs/heads/b", "refs/heads/new/name", 
				"refs/heads/a");
		}

		/// <exception cref="System.IO.IOException"></exception>
		[NUnit.Framework.Test]
		public virtual void TestRenameRefNameColission1avoided()
		{
			// setup
			ObjectId rb = db.Resolve("refs/heads/b");
			WriteSymref(Constants.HEAD, "refs/heads/a");
			RefUpdate updateRef = db.UpdateRef("refs/heads/a");
			updateRef.SetNewObjectId(rb);
			updateRef.SetRefLogMessage("Setup", false);
			NUnit.Framework.Assert.AreEqual(RefUpdate.Result.FAST_FORWARD, updateRef.Update()
				);
			ObjectId oldHead = db.Resolve(Constants.HEAD);
			NUnit.Framework.Assert.IsTrue(rb.Equals(oldHead));
			// assumption for this test
			WriteReflog(db, rb, "Just a message", "refs/heads/a");
			NUnit.Framework.Assert.IsTrue(new FilePath(db.Directory, "logs/refs/heads/a").Exists
				(), "internal check, we have a log");
			// Now this is our test
			RefRename renameRef = db.RenameRef("refs/heads/a", "refs/heads/a/b");
			RefUpdate.Result result = renameRef.Rename();
			NUnit.Framework.Assert.AreEqual(RefUpdate.Result.RENAMED, result);
			NUnit.Framework.Assert.IsNull(db.Resolve("refs/heads/a"));
			NUnit.Framework.Assert.AreEqual(rb, db.Resolve("refs/heads/a/b"));
			NUnit.Framework.Assert.AreEqual(3, db.GetReflogReader("a/b").GetReverseEntries().
				Count);
			NUnit.Framework.Assert.AreEqual("Branch: renamed a to a/b", db.GetReflogReader("a/b"
				).GetReverseEntries()[0].GetComment());
			NUnit.Framework.Assert.AreEqual("Just a message", db.GetReflogReader("a/b").GetReverseEntries
				()[1].GetComment());
			NUnit.Framework.Assert.AreEqual("Setup", db.GetReflogReader("a/b").GetReverseEntries
				()[2].GetComment());
			// same thing was logged to HEAD
			NUnit.Framework.Assert.AreEqual("Branch: renamed a to a/b", db.GetReflogReader("HEAD"
				).GetReverseEntries()[0].GetComment());
		}

		/// <exception cref="System.IO.IOException"></exception>
		[NUnit.Framework.Test]
		public virtual void TestRenameRefNameColission2avoided()
		{
			// setup
			ObjectId rb = db.Resolve("refs/heads/b");
			WriteSymref(Constants.HEAD, "refs/heads/prefix/a");
			RefUpdate updateRef = db.UpdateRef("refs/heads/prefix/a");
			updateRef.SetNewObjectId(rb);
			updateRef.SetRefLogMessage("Setup", false);
			updateRef.SetForceUpdate(true);
			NUnit.Framework.Assert.AreEqual(RefUpdate.Result.FORCED, updateRef.Update());
			ObjectId oldHead = db.Resolve(Constants.HEAD);
			NUnit.Framework.Assert.IsTrue(rb.Equals(oldHead));
			// assumption for this test
			WriteReflog(db, rb, "Just a message", "refs/heads/prefix/a");
			NUnit.Framework.Assert.IsTrue(new FilePath(db.Directory, "logs/refs/heads/prefix/a"
				).Exists(), "internal check, we have a log");
			// Now this is our test
			RefRename renameRef = db.RenameRef("refs/heads/prefix/a", "refs/heads/prefix");
			RefUpdate.Result result = renameRef.Rename();
			NUnit.Framework.Assert.AreEqual(RefUpdate.Result.RENAMED, result);
			NUnit.Framework.Assert.IsNull(db.Resolve("refs/heads/prefix/a"));
			NUnit.Framework.Assert.AreEqual(rb, db.Resolve("refs/heads/prefix"));
			NUnit.Framework.Assert.AreEqual(3, db.GetReflogReader("prefix").GetReverseEntries
				().Count);
			NUnit.Framework.Assert.AreEqual("Branch: renamed prefix/a to prefix", db.GetReflogReader
				("prefix").GetReverseEntries()[0].GetComment());
			NUnit.Framework.Assert.AreEqual("Just a message", db.GetReflogReader("prefix").GetReverseEntries
				()[1].GetComment());
			NUnit.Framework.Assert.AreEqual("Setup", db.GetReflogReader("prefix").GetReverseEntries
				()[2].GetComment());
			NUnit.Framework.Assert.AreEqual("Branch: renamed prefix/a to prefix", db.GetReflogReader
				("HEAD").GetReverseEntries()[0].GetComment());
		}

		/// <exception cref="System.IO.IOException"></exception>
		private void WriteReflog(Repository db, ObjectId newId, string msg, string refName
			)
		{
			RefDirectory refs = (RefDirectory)db.RefDatabase;
			RefDirectoryUpdate update = ((RefDirectoryUpdate)refs.NewUpdate(refName, true));
			update.SetNewObjectId(newId);
			refs.Log(update, msg, true);
		}

		[System.Serializable]
		internal class SubclassedId : ObjectId
		{
			internal SubclassedId(AnyObjectId src) : base(src)
			{
			}
		}
	}
}