Fix ChangeDirectory method

Fix GetCanonicalPath method
Add tests for ChangeDirectory

Renci.SshClient/Renci.SshNet.Tests/Renci.SshNet.Tests.csproj

@@ -63,6 +63,7 @@
     <Compile Include="Security\TestHostKey.cs" />
     <Compile Include="Security\TestKeyExchange.cs" />
     <Compile Include="Security\TestPrivateKeyFile.cs" />
+    <Compile Include="SftpClientTests\ChangeDirectory.cs" />
     <Compile Include="SftpClientTests\CreateDirectoryTest.cs" />
     <Compile Include="SftpClientTests\DeleteDirectoryTest.cs" />
     <Compile Include="SftpClientTests\DeleteFileTest.cs" />

Renci.SshClient/Renci.SshNet.Tests/SftpClientTests/ChangeDirectory.cs

@@ -0,0 +1,97 @@
+using System;
+using System.Text;
+using System.Collections.Generic;
+using System.Linq;
+using Microsoft.VisualStudio.TestTools.UnitTesting;
+using Renci.SshNet.Tests.Properties;
+using Renci.SshNet.Common;
+
+namespace Renci.SshNet.Tests.SftpClientTests
+{
+    [TestClass]
+    public class ChangeDirectory
+    {
+        [TestInitialize()]
+        public void CleanCurrentFolder()
+        {
+            using (var client = new SshClient(Resources.HOST, Resources.USERNAME, Resources.PASSWORD))
+            {
+                client.Connect();
+                client.RunCommand("rm -rf *");
+                client.Disconnect();
+            }
+        }
+
+        [TestMethod]
+        [TestCategory("Sftp")]
+        [ExpectedException(typeof(SshFileNotFoundException))]
+        public void Test_Sftp_ChangeDirectory_Root_Dont_Exists()
+        {
+            using (var sftp = new SftpClient(Resources.HOST, Resources.USERNAME, Resources.PASSWORD))
+            {
+                sftp.Connect();
+                sftp.ChangeDirectory("/asdasd");
+            }
+        }
+
+        [TestMethod]
+        [TestCategory("Sftp")]
+        [ExpectedException(typeof(SshFileNotFoundException))]
+        public void Test_Sftp_ChangeDirectory_Root_With_Slash_Dont_Exists()
+        {
+            using (var sftp = new SftpClient(Resources.HOST, Resources.USERNAME, Resources.PASSWORD))
+            {
+                sftp.Connect();
+                sftp.ChangeDirectory("/asdasd/");
+            }
+        }
+
+        [TestMethod]
+        [TestCategory("Sftp")]
+        [ExpectedException(typeof(SshFileNotFoundException))]
+        public void Test_Sftp_ChangeDirectory_Subfolder_Dont_Exists()
+        {
+            using (var sftp = new SftpClient(Resources.HOST, Resources.USERNAME, Resources.PASSWORD))
+            {
+                sftp.Connect();
+                sftp.ChangeDirectory("/asdasd/sssddds");
+            }
+        }
+
+        [TestMethod]
+        [TestCategory("Sftp")]
+        [ExpectedException(typeof(SshFileNotFoundException))]
+        public void Test_Sftp_ChangeDirectory_Subfolder_With_Slash_Dont_Exists()
+        {
+            using (var sftp = new SftpClient(Resources.HOST, Resources.USERNAME, Resources.PASSWORD))
+            {
+                sftp.Connect();
+                sftp.ChangeDirectory("/asdasd/sssddds/");
+            }
+        }
+
+        [TestMethod]
+        [TestCategory("Sftp")]
+        public void Test_Sftp_ChangeDirectory_Which_Exists()
+        {
+            using (var sftp = new SftpClient(Resources.HOST, Resources.USERNAME, Resources.PASSWORD))
+            {
+                sftp.Connect();
+                sftp.ChangeDirectory("/usr");
+                Assert.AreEqual("/usr", sftp.WorkingDirectory);
+            }
+        }
+
+        [TestMethod]
+        [TestCategory("Sftp")]
+        public void Test_Sftp_ChangeDirectory_Which_Exists_With_Slash()
+        {
+            using (var sftp = new SftpClient(Resources.HOST, Resources.USERNAME, Resources.PASSWORD))
+            {
+                sftp.Connect();
+                sftp.ChangeDirectory("/usr/");
+                Assert.AreEqual("/usr", sftp.WorkingDirectory);
+            }
+        }
+    }
+}

Renci.SshClient/Renci.SshNet/Renci.SshNet.csproj

@@ -130,6 +130,7 @@
     <Compile Include="Security\Cryptography\Ciphers\DesCipher.cs" />
     <Compile Include="Sftp\CloseCommand.cs" />
     <Compile Include="Sftp\OpenCommand.cs" />
+    <Compile Include="Sftp\OpenDirectoryCommand.cs" />
     <Compile Include="Sftp\ReadCommand.cs" />
     <Compile Include="Sftp\SetStatusCommand.cs" />
     <Compile Include="Sftp\SftpFileAttributes.cs" />

Renci.SshClient/Renci.SshNet/Sftp/OpenDirectoryCommand.cs

@@ -0,0 +1,47 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using Renci.SshNet.Common;
+using Renci.SshNet.Sftp.Messages;
+using System.Globalization;
+
+namespace Renci.SshNet.Sftp
+{
+    internal class OpenDirectoryCommand : SftpCommand
+    {
+        private string _path;
+
+        public byte[] Handle { get; private set; }
+
+        public OpenDirectoryCommand(SftpSession sftpSession, string path)
+            : base(sftpSession)
+        {
+            this._path = path;
+        }
+
+        protected override void OnExecute()
+        {
+            this.SendOpenDirMessage(this._path);
+        }
+
+        protected override void OnHandle(byte[] handle)
+        {
+            base.OnHandle(handle);
+
+            this.Handle = handle;
+
+            this.CompleteExecution();
+        }
+
+        protected override void OnStatus(StatusCodes statusCode, string errorMessage, string language)
+        {
+            base.OnStatus(statusCode, errorMessage, language);
+
+            if (statusCode == StatusCodes.NoSuchFile)
+            {
+                throw new SshFileNotFoundException(string.Format(CultureInfo.CurrentCulture, "Path '{0}' is not found.", this._path));
+            }
+        }
+    }
+}

Renci.SshClient/Renci.SshNet/Sftp/SftpSession.cs

@@ -101,7 +101,25 @@ namespace Renci.SshNet.Sftp
 
         public void ChangeDirectory(string path)
         {
-            this.WorkingDirectory = this.GetCanonicalPath(path);
+            var fullPath = this.GetCanonicalPath(path);
+
+            //  Open directory
+            using (var openCmd = new OpenDirectoryCommand(this, fullPath))
+            {
+                openCmd.CommandTimeout = this._operationTimeout;
+
+                //  Try to open directory and throw an exception if can't
+                openCmd.Execute();
+
+                using (SftpCommand closeCmd = new CloseCommand(this, openCmd.Handle))
+                {
+                    closeCmd.CommandTimeout = this._operationTimeout;
+
+                    closeCmd.Execute();
+                }
+            }
+
+            this.WorkingDirectory = fullPath;
         }
 
         /// <summary>
@@ -141,6 +159,9 @@ namespace Renci.SshNet.Sftp
 
             var partialFullPath = string.Join("/", pathParts, 0, pathParts.Length - 1);
 
+            if (string.IsNullOrEmpty(partialFullPath))
+                partialFullPath = "/";
+
             canonizedPath = this.GetRealPath(partialFullPath);
 
             if (string.IsNullOrEmpty(canonizedPath))