Normalize submodule paths on lookup

Fixes libgit2/libgit2#1845

Author: dahlbyk

LibGit2Sharp.Tests/SubmoduleFixture.cs

@@ -1,4 +1,5 @@
 using System;
+using System.IO;
 using System.Linq;
 using LibGit2Sharp.Tests.TestHelpers;
 using Xunit;
@@ -103,14 +104,17 @@ public void CanEnumerateRepositorySubmodules()
         }
 
         [Theory]
-        [InlineData("sm_changed_head")]
-        [InlineData("sm_changed_head/")]
-        public void CanStageChangeInSubmoduleViaIndexStage(string submodulePath)
+        [InlineData("sm_changed_head", false)]
+        [InlineData("sm_changed_head", true)]
+        public void CanStageChangeInSubmoduleViaIndexStage(string submodulePath, bool appendPathSeparator)
         {
+            submodulePath += appendPathSeparator ? Path.DirectorySeparatorChar : default(char?);
+
             var path = CloneSubmoduleTestRepo();
             using (var repo = new Repository(path))
             {
                 var submodule = repo.Submodules[submodulePath];
+                Assert.NotNull(submodule);
 
                 var statusBefore = submodule.RetrieveStatus();
                 Assert.Equal(SubmoduleStatus.WorkDirModified, statusBefore & SubmoduleStatus.WorkDirModified);
@@ -123,21 +127,24 @@ public void CanStageChangeInSubmoduleViaIndexStage(string submodulePath)
         }
 
         [Theory]
-        [InlineData("sm_changed_head")]
-        [InlineData("sm_changed_head/")]
-        public void CanStageChangeInSubmoduleViaIndexStageWithOtherPaths(string submodulePath)
+        [InlineData("sm_changed_head", false)]
+        [InlineData("sm_changed_head", true)]
+        public void CanStageChangeInSubmoduleViaIndexStageWithOtherPaths(string submodulePath, bool appendPathSeparator)
         {
+            submodulePath += appendPathSeparator ? Path.DirectorySeparatorChar : default(char?);
+
             var path = CloneSubmoduleTestRepo();
             using (var repo = new Repository(path))
             {
                 var submodule = repo.Submodules[submodulePath];
+                Assert.NotNull(submodule);
 
                 var statusBefore = submodule.RetrieveStatus();
                 Assert.Equal(SubmoduleStatus.WorkDirModified, statusBefore & SubmoduleStatus.WorkDirModified);
 
                 Touch(repo.Info.WorkingDirectory, "new-file.txt");
 
-                repo.Index.Stage(new[]{ "new-file.txt", submodulePath, "does-not-exist.txt" });
+                repo.Index.Stage(new[] { "new-file.txt", submodulePath, "does-not-exist.txt" });
 
                 var statusAfter = submodule.RetrieveStatus();
                 Assert.Equal(SubmoduleStatus.IndexModified, statusAfter & SubmoduleStatus.IndexModified);

LibGit2Sharp/Core/NativeMethods.cs

@@ -1047,7 +1047,7 @@ internal delegate int git_status_cb(
         internal static extern int git_submodule_lookup(
             out SubmoduleSafeHandle reference,
             RepositorySafeHandle repo,
-            [MarshalAs(UnmanagedType.CustomMarshaler, MarshalCookie = UniqueId.UniqueIdentifier, MarshalTypeRef = typeof(Utf8Marshaler))] string name);
+            [MarshalAs(UnmanagedType.CustomMarshaler, MarshalCookie = UniqueId.UniqueIdentifier, MarshalTypeRef = typeof(FilePathMarshaler))] FilePath name);
 
         internal delegate int submodule_callback(
             IntPtr sm,

LibGit2Sharp/Core/Proxy.cs

@@ -1978,7 +1978,7 @@ public static ICollection<TResult> git_status_foreach<TResult>(RepositorySafeHan
         /// Returns a handle to the corresponding submodule,
         /// or an invalid handle if a submodule is not found.
         /// </summary>
-        public static SubmoduleSafeHandle git_submodule_lookup(RepositorySafeHandle repo, string name)
+        public static SubmoduleSafeHandle git_submodule_lookup(RepositorySafeHandle repo, FilePath name)
         {
             using (ThreadAffinity())
             {