Delegate the handling of the default refSpec to libgit2 when creating a new Remote

Fix #164

Author: tclem

LibGit2Sharp.Tests/RemoteFixture.cs

@@ -86,8 +86,7 @@ public void CreatingANewRemoteAddsADefaultRefSpec()
                 var refSpec = repo.Config.Get<string>("remote", remote.Name, "fetch", null);
                 Assert.NotNull(refSpec);
 
-                //TODO: Uncomment the line below once https://github.com/libgit2/libgit2/pull/737 is merged
-                //Assert.Equal("+refs/heads/*:refs/remotes/upstream/*", refSpec);
+                Assert.Equal("+refs/heads/*:refs/remotes/upstream/*", refSpec);
             }
         }
 
@@ -107,8 +106,7 @@ public void CanAddANewRemoteWithAFetchRefSpec()
                 var refSpec = repo.Config.Get<string>("remote", name, "fetch", null);
                 Assert.NotNull(refSpec);
 
-                //TODO: Uncomment the line below once https://github.com/libgit2/libgit2/pull/737 is merged
-                //Assert.Equal(fetchRefSpec, refSpec);
+                Assert.Equal(fetchRefSpec, refSpec);
             }
         }
     }

LibGit2Sharp/Core/NativeMethods.cs

@@ -502,6 +502,13 @@ public static extern int git_remote_load(
         [return : MarshalAs(UnmanagedType.CustomMarshaler, MarshalTypeRef = typeof(Utf8Marshaler))]
         public static extern string git_remote_name(RemoteSafeHandle remote);
 
+        [DllImport(libgit2)]
+        public static extern int git_remote_add(
+            out RemoteSafeHandle remote,
+            RepositorySafeHandle repo,
+            [MarshalAs(UnmanagedType.CustomMarshaler, MarshalTypeRef = typeof(Utf8Marshaler))] string name,
+            [MarshalAs(UnmanagedType.CustomMarshaler, MarshalTypeRef = typeof(Utf8Marshaler))] string url);
+
         [DllImport(libgit2)]
         public static extern int git_remote_new(
             out RemoteSafeHandle remote,

LibGit2Sharp/RemoteCollection.cs

@@ -91,9 +91,17 @@ IEnumerator IEnumerable.GetEnumerator()
         /// <returns>A new <see cref = "Remote" />.</returns>
         public virtual Remote Add(string name, string url)
         {
-            string fetchRefSpec = string.Format("+refs/heads/*:refs/remotes/{0}/*", name);
+            Ensure.ArgumentNotNull(name, "name");
+            Ensure.ArgumentNotNull(url, "url");
+
+            RemoteSafeHandle handle;
+
+            Ensure.Success(NativeMethods.git_remote_add(out handle, repository.Handle, name, url));
 
-            return Add(name, url, fetchRefSpec);
+            using (handle)
+            {
+                return Remote.CreateFromPtr(handle);
+            }
         }
 
         /// <summary>