Added first draft implementation of Tag applying.

libgit2sharp.Tests/ApplyingATag.cs

+using System;
+using NUnit.Framework;
+
+namespace libgit2sharp.Tests
+{
+    [TestFixture]
+    public class ApplyingATag : ReadWriteRepositoryFixtureBase
+    {
+        [Test]
+        public void ShouldWork() // TODO: Split into different tests (returnATag, PersistTheObject, MultipleApplies, ...)
+        {
+            const string targetId = "8496071c1b46c854b31185ea97743be6a8774479";
+            var signature = new Signature("me", "me@me.me", DateTimeOffset.Now);
+
+            Tag appliedTag;
+            using (var repo = new Repository(PathToRepository))
+            {
+                appliedTag = repo.ApplyTag(targetId, "tagged", "messaged", signature);
+            }
+
+            Tag retrievedTag;
+            using (var repo = new Repository(PathToRepository))
+            {
+                retrievedTag = repo.Resolve<Tag>(appliedTag.Id);
+            }
+
+            Assert.AreEqual(appliedTag.Id, retrievedTag.Id);
+            // TODO: Finalize comparison
+        }
+    }
+}
\ No newline at end of file

libgit2sharp.Tests/libgit2sharp.Tests.csproj

@@ -43,6 +43,9 @@
     <Reference Include="System.Xml" />
   </ItemGroup>
   <ItemGroup>
+    <Compile Include="ApplyingATag.cs">
+      <SubType>Code</SubType>
+    </Compile>
     <Compile Include="GitDateFixture.cs" />
     <Compile Include="ObjectIdFixture.cs" />
     <Compile Include="ReadOnlyRepositoryFixtureBase.cs" />

libgit2sharp/Repository.cs

@@ -90,5 +90,20 @@ public object Resolve(string objectId, Type expectedType)
         {
             return _resolver.Resolve(objectId, expectedType);
         }
+
+        public Tag ApplyTag(string targetId, string tagName, string tagMessage, Signature signature)
+        {
+            // TODO: To be refactored.
+            IntPtr tag;
+            OperationResult t = LibGit2Api.wrapped_git_apply_tag(out tag ,_lifecycleManager.RepositoryPtr, targetId, tagName, tagMessage, signature.Name, signature.Email, (ulong)((GitDate)signature.When).UnixTimeStamp);
+            return (Tag)BuildTag(tag);
+        }
+
+        private static object BuildTag(IntPtr gitObjectPtr)
+        {
+            // TODO: Duplicated from ObjectResolver
+            var gitTag = (git_tag)Marshal.PtrToStructure(gitObjectPtr, typeof(git_tag));
+            return gitTag.Build();
+        }
     }
 }
\ No newline at end of file

libgit2sharp/Wrapper/LibGit2Api.cs

@@ -27,5 +27,9 @@ internal static class LibGit2Api
 
         [DllImport(Libgit2)]
         public static extern OperationResult wrapped_git_odb_read(out git_rawobj rawObject, [In] IntPtr repository, [In] string objectId);
+
+        [DllImport(Libgit2)]
+        // TODO: Try to use a git_person struct
+        public static extern OperationResult wrapped_git_apply_tag(out IntPtr tagPtr, [In] IntPtr repository, [In] string targetId, [In] string tagName, [In] string tagMessage, [In] string taggerName, [In] string taggerEmail, ulong taggerTime);
     }
 }
\ No newline at end of file

libgit2wrap/src/libgit2wrap.c

@@ -99,5 +99,39 @@ int wrapped_git_odb_read(git_rawobj* obj_out, git_repository* repo, const char *
 	if (error != GIT_SUCCESS)
 		return error;
 
+	return error;
+}
+
+int wrapped_git_apply_tag(git_tag** tag_out, git_repository* repo, const char *raw_target_id, const char *tag_name, const char *tag_message, const char *tagger_name, const char *tagger_email, time_t tagger_time)
+{
+	git_oid id;
+	int error;
+	git_object* target;
+	git_tag* tag;
+
+	error = git_oid_mkstr(&id, raw_target_id);
+	if (error != GIT_SUCCESS)
+		return error;
+
+	error = git_repository_lookup(&target, repo, &id, GIT_OBJ_ANY);
+	if (error != GIT_SUCCESS)
+		return error;
+
+	error = git_tag_new(&tag, repo);
+	if (error != GIT_SUCCESS)
+		return error;
+
+	git_tag_set_tagger(tag, tagger_name, tagger_email, tagger_time);
+	git_tag_set_name(tag, tag_name);
+	git_tag_set_target(tag, target);
+	
+	git_tag_set_message(tag, tag_message);
+
+	error = git_object_write((git_object*)tag);
+	if (error != GIT_SUCCESS)
+		return error;
+
+	*tag_out = tag;
+
 	return error;
 }
\ No newline at end of file

libgit2wrap/src/libgit2wrap.h

@@ -3,19 +3,6 @@
 
 #include <git2.h>
 
-typedef struct wrapped_git_repository {
-	size_t db;
-	size_t index;
-	size_t objects;
-	
-	char *path_repository;
-	char *path_index;
-	char *path_odb;
-	char *path_workdir;
-
-	unsigned is_bare:1;
-} wrapped_git_repository ;
-
 GIT_BEGIN_DECL
 
 GIT_EXTERN(int) wrapped_git_repository_open(git_repository** repo_out, const char* path);
@@ -24,7 +11,8 @@ GIT_EXTERN(void) wrapped_git_repository_free(git_repository* repo);
 GIT_EXTERN(int) wrapped_git_repository_lookup(git_object** obj_out, git_repository* repo, const char* raw_id, git_otype type);
 GIT_EXTERN(int) wrapped_git_odb_exists(git_repository* repo, const char* raw_id);
 GIT_EXTERN(int) wrapped_git_odb_read_header(git_rawobj* obj_out, git_repository* repo, const char* raw_id);
-GIT_EXTERN(int) wrapped_git_odb_read(git_rawobj* obj_out, git_repository* repo, const char* raw_id);
+GIT_EXTERN(int) wrapped_git_odb_read(git_rawobj** obj_out, git_repository* repo, const char* raw_id);
+GIT_EXTERN(int) wrapped_git_apply_tag(git_tag* tag_out, git_repository* repo, const char *raw_target_id, const char *tag_name, const char *tag_message, const char *tagger_name, const char *tagger_email, time_t tagger_time);
 
 GIT_END_DECL