Simplify git_revparse_ext usage

Author: nulltoken

LibGit2Sharp/Core/DisposableTuple.cs

@@ -0,0 +1,33 @@
+using System;
+using LibGit2Sharp.Core.Handles;
+
+namespace LibGit2Sharp.Core
+{
+    internal class DisposableTuple<T1, T2> : IDisposable
+        where T1 : IDisposable where T2 : IDisposable
+    {
+        private Tuple<T1, T2> _tuple;
+
+        public DisposableTuple(T1 item1, T2 item2)
+        {
+            _tuple = new Tuple<T1, T2>(item1, item2);
+        }
+
+        public T1 Item1 { get { return _tuple.Item1; } }
+        public T2 Item2 { get { return _tuple.Item2; } }
+
+        public void Dispose()
+        {
+            if (_tuple == null)
+            {
+                return;
+            }
+
+            _tuple.Item1.SafeDispose();
+            _tuple.Item2.SafeDispose();
+            _tuple = null;
+
+            GC.SuppressFinalize(this);
+        }
+    }
+}

LibGit2Sharp/Core/Proxy.cs

@@ -2571,7 +2571,7 @@ public static void git_revert(
 
         #region git_revparse_
 
-        public static Tuple<GitObjectSafeHandle, ReferenceSafeHandle> git_revparse_ext(RepositorySafeHandle repo, string objectish)
+        public static DisposableTuple<GitObjectSafeHandle, ReferenceSafeHandle> git_revparse_ext(RepositorySafeHandle repo, string objectish)
         {
             using (ThreadAffinity())
             {
@@ -2592,24 +2592,10 @@ public static Tuple<GitObjectSafeHandle, ReferenceSafeHandle> git_revparse_ext(R
                         break;
                 }
 
-                return new Tuple<GitObjectSafeHandle, ReferenceSafeHandle>(obj, reference);
+                return new DisposableTuple<GitObjectSafeHandle, ReferenceSafeHandle>(obj, reference);
             }
         }
 
-        public static GitObjectSafeHandle git_revparse_single(RepositorySafeHandle repo, string objectish)
-        {
-            var handles = git_revparse_ext(repo, objectish);
-
-            if (handles == null)
-            {
-                return null;
-            }
-
-            handles.Item2.Dispose();
-
-            return handles.Item1;
-        }
-
         #endregion
 
         #region git_revwalk_

LibGit2Sharp/LibGit2Sharp.csproj

@@ -69,6 +69,7 @@
     <Compile Include="CommitSortStrategies.cs" />
     <Compile Include="CompareOptions.cs" />
     <Compile Include="Core\FileHistory.cs" />
+    <Compile Include="Core\DisposableTuple.cs" />
     <Compile Include="Core\Platform.cs" />
     <Compile Include="Core\Handles\ConflictIteratorSafeHandle.cs" />
     <Compile Include="DescribeOptions.cs" />

LibGit2Sharp/Repository.cs

@@ -485,9 +485,9 @@ internal GitObject Lookup(string objectish, GitObjectType type, LookUpOptions lo
             Ensure.ArgumentNotNullOrEmptyString(objectish, "objectish");
 
             GitObject obj;
-            using (GitObjectSafeHandle sh = Proxy.git_revparse_single(handle, objectish))
+            using (DisposableTuple<GitObjectSafeHandle, ReferenceSafeHandle> handles = Proxy.git_revparse_ext(handle, objectish))
             {
-                if (sh == null)
+                if (handles == null)
                 {
                     if (lookUpOptions.HasFlag(LookUpOptions.ThrowWhenNoGitObjectHasBeenFound))
                     {
@@ -497,14 +497,15 @@ internal GitObject Lookup(string objectish, GitObjectType type, LookUpOptions lo
                     return null;
                 }
 
-                GitObjectType objType = Proxy.git_object_type(sh);
+                var objH = handles.Item1;
+                GitObjectType objType = Proxy.git_object_type(objH);
 
                 if (type != GitObjectType.Any && objType != type)
                 {
                     return null;
                 }
 
-                obj = GitObject.BuildFrom(this, Proxy.git_object_id(sh), objType, PathFromRevparseSpec(objectish));
+                obj = GitObject.BuildFrom(this, Proxy.git_object_id(objH), objType, PathFromRevparseSpec(objectish));
             }
 
             if (lookUpOptions.HasFlag(LookUpOptions.DereferenceResultToCommit))
@@ -752,17 +753,18 @@ public Branch Checkout(string committishOrBranchSpec, CheckoutOptions options)
             Ensure.ArgumentNotNullOrEmptyString(committishOrBranchSpec, "committishOrBranchSpec");
             Ensure.ArgumentNotNull(options, "options");
 
-            var handles = Proxy.git_revparse_ext(Handle, committishOrBranchSpec);
-            if (handles == null)
-            {
-                Ensure.GitObjectIsNotNull(null, committishOrBranchSpec);
-            }
-
-            var objH = handles.Item1;
-            var refH = handles.Item2;
             GitObject obj;
-            try
+
+            using (DisposableTuple<GitObjectSafeHandle, ReferenceSafeHandle> handles = Proxy.git_revparse_ext(Handle, committishOrBranchSpec))
             {
+                if (handles == null)
+                {
+                    Ensure.GitObjectIsNotNull(null, committishOrBranchSpec);
+                }
+
+                var objH = handles.Item1;
+                var refH = handles.Item2;
+
                 if (!refH.IsInvalid)
                 {
                     var reference = Reference.BuildFromPtr<Reference>(refH, this);
@@ -776,11 +778,6 @@ public Branch Checkout(string committishOrBranchSpec, CheckoutOptions options)
                 obj = GitObject.BuildFrom(this, Proxy.git_object_id(objH), Proxy.git_object_type(objH),
                                               PathFromRevparseSpec(committishOrBranchSpec));
             }
-            finally
-            {
-                objH.Dispose();
-                refH.Dispose();
-            }
 
             Commit commit = obj.DereferenceToCommit(true);
             Checkout(commit.Tree, options, committishOrBranchSpec);