Teach Repository to Checkout paths

LibGit2Sharp.Tests/CheckoutFixture.cs

@@ -922,6 +922,74 @@ public void CanCheckoutDetachedHead()
             }
         }
 
+        [Theory]
+        [InlineData("master", "6dcf9bf", "readme.txt", FileStatus.Added)]
+        [InlineData("master", "refs/tags/lw", "readme.txt", FileStatus.Added)]
+        [InlineData("master", "i-do-numbers", "super-file.txt", FileStatus.Added)]
+        [InlineData("i-do-numbers", "diff-test-cases", "numbers.txt", FileStatus.Staged)]
+        public void CanCheckoutPath(string originalBranch, string checkoutFrom, string path, FileStatus expectedStatus)
+        {
+            string repoPath = CloneStandardTestRepo();
+            using (var repo = new Repository(repoPath))
+            {
+                // Set the working directory to the current head
+                ResetAndCleanWorkingDirectory(repo);
+
+                repo.Checkout(originalBranch);
+                Assert.False(repo.Index.RetrieveStatus().IsDirty);
+
+                repo.CheckoutPaths(checkoutFrom, new string[] { path }, CheckoutModifiers.None, null, null);
+
+                Assert.Equal(expectedStatus, repo.Index.RetrieveStatus(path));
+                Assert.Equal(1, repo.Index.RetrieveStatus().Count());
+            }
+        }
+
+        [Fact]
+        public void CanCheckoutPaths()
+        {
+            string repoPath = CloneStandardTestRepo();
+            var checkoutPaths = new[] { "numbers.txt", "super-file.txt" };
+
+            using (var repo = new Repository(repoPath))
+            {
+                // Set the working directory to the current head
+                ResetAndCleanWorkingDirectory(repo);
+                Assert.False(repo.Index.RetrieveStatus().IsDirty);
+
+                repo.CheckoutPaths("i-do-numbers", checkoutPaths, CheckoutModifiers.None, null, null);
+
+                foreach (string checkoutPath in checkoutPaths)
+                {
+                    Assert.Equal(FileStatus.Added, repo.Index.RetrieveStatus(checkoutPath));
+                }
+            }
+        }
+
+        [Theory]
+        [InlineData("new.txt")]
+        [InlineData("1.txt")]
+        public void CanCheckoutPathFromCurrentBranch(string fileName)
+        {
+            string repoPath = CloneStandardTestRepo();
+
+            using (var repo = new Repository(repoPath))
+            {
+                // Set the working directory to the current head
+                ResetAndCleanWorkingDirectory(repo);
+
+                Assert.False(repo.Index.RetrieveStatus().IsDirty);
+
+                Touch(repo.Info.WorkingDirectory, fileName, "new text file");
+
+                Assert.True(repo.Index.RetrieveStatus().IsDirty);
+
+                repo.CheckoutPaths("HEAD", new string[] { fileName }, CheckoutModifiers.Force, null, null);
+
+                Assert.False(repo.Index.RetrieveStatus().IsDirty);
+            }
+        }
+
         /// <summary>
         /// Helper method to populate a simple repository with
         /// a single file and two branches.

LibGit2Sharp/BranchCollectionExtensions.cs

@@ -20,10 +20,7 @@ public static Branch Add(this BranchCollection branches, string name, string com
             Ensure.ArgumentNotNullOrEmptyString(name, "name");
             Ensure.ArgumentNotNullOrEmptyString(committish, "committish");
 
-            var commit = (Commit)branches.repo.Lookup(committish, GitObjectType.Any,
-                LookUpOptions.ThrowWhenNoGitObjectHasBeenFound |
-                LookUpOptions.DereferenceResultToCommit |
-                LookUpOptions.ThrowWhenCanNotBeDereferencedToACommit);
+            var commit = branches.repo.LookupCommit(committish);
 
             return branches.Add(name, commit, allowOverwrite);
         }

LibGit2Sharp/Core/GitCheckoutOpts.cs

@@ -95,7 +95,7 @@ internal enum CheckoutStrategy
             IntPtr payload);
 
     [StructLayout(LayoutKind.Sequential)]
-    internal struct GitCheckoutOpts
+    internal struct GitCheckoutOpts :IDisposable
     {
         public uint version;
 
@@ -113,9 +113,19 @@ internal struct GitCheckoutOpts
         public progress_cb progress_cb;
         public IntPtr progress_payload;
 
-        public UnSafeNativeMethods.git_strarray paths;
+        public GitStrArrayIn paths;
 
         public IntPtr baseline;
         public IntPtr target_directory;
+
+        public void Dispose()
+        {
+            if (paths == null)
+            {
+                return;
+            }
+
+            paths.Dispose();
+        }
     }
 }

LibGit2Sharp/Core/GitDiff.cs

@@ -113,52 +113,6 @@ internal enum GitDiffOptionFlags
         GIT_DIFF_IGNORE_FILEMODE = (1 << 17),
     }
 
-    [StructLayout(LayoutKind.Sequential)]
-    internal class GitStrArrayIn : IDisposable
-    {
-        public IntPtr strings;
-        public uint size;
-
-        public static GitStrArrayIn BuildFrom(FilePath[] paths)
-        {
-            var nbOfPaths = paths.Length;
-            var pathPtrs = new IntPtr[nbOfPaths];
-
-            for (int i = 0; i < nbOfPaths; i++)
-            {
-                var s = paths[i].Posix;
-                pathPtrs[i] = FilePathMarshaler.FromManaged(s);
-            }
-
-            int dim = IntPtr.Size * nbOfPaths;
-
-            IntPtr arrayPtr = Marshal.AllocHGlobal(dim);
-            Marshal.Copy(pathPtrs, 0, arrayPtr, nbOfPaths);
-
-            return new GitStrArrayIn { strings = arrayPtr, size = (uint)nbOfPaths };
-        }
-
-        public void Dispose()
-        {
-            if (size == 0)
-            {
-                return;
-            }
-
-            var nbOfPaths = (int)size;
-
-            var pathPtrs = new IntPtr[nbOfPaths];
-            Marshal.Copy(strings, pathPtrs, 0, nbOfPaths);
-
-            for (int i = 0; i < nbOfPaths; i ++)
-            {
-                Marshal.FreeHGlobal(pathPtrs[i]);
-            }
-
-            Marshal.FreeHGlobal(strings);
-        }
-    }
-
     internal delegate int diff_notify_cb(
         IntPtr diff_so_far,
         IntPtr delta_to_add,
@@ -191,8 +145,6 @@ public void Dispose()
             }
 
             PathSpec.Dispose();
-
-            PathSpec.size = 0;
         }
     }
 

LibGit2Sharp/Core/GitStrArrayIn.cs

@@ -0,0 +1,55 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Runtime.InteropServices;
+using System.Text;
+
+namespace LibGit2Sharp.Core
+{
+    [StructLayout(LayoutKind.Sequential)]
+    internal class GitStrArrayIn : IDisposable
+    {
+        public IntPtr strings;
+        public uint size;
+
+        public static GitStrArrayIn BuildFrom(FilePath[] paths)
+        {
+            var nbOfPaths = paths.Length;
+            var pathPtrs = new IntPtr[nbOfPaths];
+
+            for (int i = 0; i < nbOfPaths; i++)
+            {
+                var s = paths[i].Posix;
+                pathPtrs[i] = FilePathMarshaler.FromManaged(s);
+            }
+
+            int dim = IntPtr.Size * nbOfPaths;
+
+            IntPtr arrayPtr = Marshal.AllocHGlobal(dim);
+            Marshal.Copy(pathPtrs, 0, arrayPtr, nbOfPaths);
+
+            return new GitStrArrayIn { strings = arrayPtr, size = (uint)nbOfPaths };
+        }
+
+        public void Dispose()
+        {
+            if (size == 0)
+            {
+                return;
+            }
+
+            var nbOfPaths = (int)size;
+
+            var pathPtrs = new IntPtr[nbOfPaths];
+            Marshal.Copy(strings, pathPtrs, 0, nbOfPaths);
+
+            for (int i = 0; i < nbOfPaths; i++)
+            {
+                Marshal.FreeHGlobal(pathPtrs[i]);
+            }
+
+            Marshal.FreeHGlobal(strings);
+            size = 0;
+        }
+    }
+}

LibGit2Sharp/Diff.cs

@@ -65,33 +65,6 @@ private static GitDiffOptions BuildOptions(DiffModifiers diffOptions, FilePath[]
             return options;
         }
 
-        private static FilePath[] ToFilePaths(Repository repo, IEnumerable<string> paths)
-        {
-            if (paths == null)
-            {
-                return null;
-            }
-
-            var filePaths = new List<FilePath>();
-
-            foreach (string path in paths)
-            {
-                if (string.IsNullOrEmpty(path))
-                {
-                    throw new ArgumentException("At least one provided path is either null or empty.", "paths");
-                }
-
-                filePaths.Add(repo.BuildRelativePathFrom(path));
-            }
-
-            if (filePaths.Count == 0)
-            {
-                throw new ArgumentException("No path has been provided.", "paths");
-            }
-
-            return filePaths.ToArray();
-        }
-
         /// <summary>
         /// Needed for mocking purposes.
         /// </summary>
@@ -287,7 +260,7 @@ private static TreeComparisonHandleRetriever IndexToTree(Repository repo)
             DiffModifiers diffOptions, IEnumerable<string> paths = null, ExplicitPathsOptions explicitPathsOptions = null, CompareOptions compareOptions = null)
         {
             var matchedPaths = new MatchedPathsAggregator();
-            var filePaths = ToFilePaths(repo, paths);
+            var filePaths = repo.ToFilePaths(paths);
 
             using (GitDiffOptions options = BuildOptions(diffOptions, filePaths, matchedPaths, compareOptions))
             using (DiffListSafeHandle diffList = comparisonHandleRetriever(oldTreeId, newTreeId, options))

LibGit2Sharp/IRepository.cs

@@ -152,6 +152,19 @@ public interface IRepository : IDisposable
         /// <returns>The <see cref="Branch"/> that was checked out.</returns>
         Branch Checkout(Commit commit, CheckoutModifiers checkoutModifiers, CheckoutProgressHandler onCheckoutProgress, CheckoutNotificationOptions checkoutNotificationOptions);
 
+        /// <summary>
+        /// Checkout files from the specified branch, reference or SHA.
+        /// <para>
+        /// This method does not switch branches or update the current repository HEAD.
+        /// </para>
+        /// </summary>
+        /// <param name="committishOrBranchSpec">A revparse spec for the commit or branch to checkout paths from.</param>
+        /// <param name="paths">The paths to checkout.</param>
+        /// <param name="checkoutOptions">Options controlling checkout behavior.</param>
+        /// <param name="onCheckoutProgress">Callback method to report checkout progress updates through.</param>
+        /// <param name="checkoutNotificationOptions"><see cref="CheckoutNotificationOptions"/> to manage checkout notifications.</param>
+        void CheckoutPaths(string committishOrBranchSpec, IList<string> paths, CheckoutModifiers checkoutOptions, CheckoutProgressHandler onCheckoutProgress, CheckoutNotificationOptions checkoutNotificationOptions);
+
         /// <summary>
         /// Try to lookup an object by its <see cref="ObjectId"/>. If no matching object is found, null will be returned.
         /// </summary>

LibGit2Sharp/LibGit2Sharp.csproj

@@ -74,6 +74,7 @@
     <Compile Include="CompareOptions.cs" />
     <Compile Include="Core\GitRepositoryInitOptions.cs" />
     <Compile Include="Core\HistoryRewriter.cs" />
+    <Compile Include="Core\GitStrArrayIn.cs" />
     <Compile Include="Core\NativeDllName.cs" />
     <Compile Include="CommitRewriteInfo.cs" />
     <Compile Include="DiffModifiers.cs" />