Fix NullReferenceException for dynamic repositories without authentication

src/GitTools.Core/GitTools.Core.Shared/Git/AuthenticationInfo.cs

@@ -7,21 +7,5 @@ public class AuthenticationInfo
         public string Username { get; set; }
         public string Password { get; set; }
         public string Token { get; set; }
-
-        public FetchOptions ToFetchOptions()
-        {
-            var fetchOptions = new FetchOptions();
-
-            if (!string.IsNullOrEmpty(Username))
-            {
-                fetchOptions.CredentialsProvider = (url, user, types) => new UsernamePasswordCredentials
-                {
-                    Username = Username,
-                    Password = Password
-                };
-            }
-
-            return fetchOptions;
-        }
     }
 }

src/GitTools.Core/GitTools.Core.Shared/Git/DynamicRepositories.cs

@@ -170,15 +170,19 @@ static void CheckoutCommit(IRepository repo, string targetCommit)
         static void CloneRepository(string repositoryUrl, string gitDirectory, AuthenticationInfo authentication)
         {
             Credentials credentials = null;
-            if (!string.IsNullOrWhiteSpace(authentication.Username) && !string.IsNullOrWhiteSpace(authentication.Password))
-            {
-                Log.Info(string.Format("Setting up credentials using name '{0}'", authentication.Username));
 
-                credentials = new UsernamePasswordCredentials
+            if (authentication != null)
+            {
+                if (!string.IsNullOrWhiteSpace(authentication.Username) && !string.IsNullOrWhiteSpace(authentication.Password))
                 {
-                    Username = authentication.Username,
-                    Password = authentication.Password
-                };
+                    Log.Info(string.Format("Setting up credentials using name '{0}'", authentication.Username));
+
+                    credentials = new UsernamePasswordCredentials
+                    {
+                        Username = authentication.Username,
+                        Password = authentication.Password
+                    };
+                }
             }
 
             Log.Info(string.Format("Retrieving git info from url '{0}'", repositoryUrl));

src/GitTools.Core/GitTools.Core.Shared/Git/Extensions/AuthenticationInfoExtensions.cs

@@ -1,11 +1,31 @@
 namespace GitTools.Git
 {
+    using LibGit2Sharp;
     using Logging;
 
     public static class AuthenticationInfoExtensions
     {
         private static readonly ILog Log = LogProvider.GetCurrentClassLogger();
 
+        public static FetchOptions ToFetchOptions(this AuthenticationInfo authenticationInfo)
+        {
+            var fetchOptions = new FetchOptions();
+
+            if (authenticationInfo != null)
+            {
+                if (!string.IsNullOrEmpty(authenticationInfo.Username))
+                {
+                    fetchOptions.CredentialsProvider = (url, user, types) => new UsernamePasswordCredentials
+                    {
+                        Username = authenticationInfo.Username,
+                        Password = authenticationInfo.Password
+                    };
+                }
+            }
+
+            return fetchOptions;
+        }
+
         public static bool IsEmpty(this AuthenticationInfo authenticationInfo)
         {
             if (authenticationInfo == null)