Set GIT_CHECKOUT_FORCE as checkout strategy when creating a worktree

Author: Enrique Raso Barbero

LibGit2Sharp.Tests/WorktreeFixture.cs

@@ -3,8 +3,6 @@
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
-using System.Text;
-using System.Threading.Tasks;
 using Xunit;
 
 namespace LibGit2Sharp.Tests
@@ -238,7 +236,7 @@ public void CanForcePruneLockedWorktree()
         }
 
         [Fact]
-        public void CanAddWorktree()
+        public void CanAddWorktree_WithUncommitedChanges()
         {
             var repoPath = SandboxWorktreeTestRepo();
             using (var repo = new Repository(repoPath))
@@ -252,15 +250,96 @@ public void CanAddWorktree()
                 Assert.False(worktree.IsLocked);
 
                 Assert.Equal(3, repo.Worktrees.Count());
+
+                // Check that branch contains same number of files and folders
+                // NOTE: There is an open bug - [Repository.Worktrees.Add leaves now worktree empty](https://github.com/libgit2/libgit2sharp/issues/2037)
+                Assert.True(repo.RetrieveStatus().IsDirty);
+                var filesInMain = GetFilesOfRepo(repoPath);
+                var filesInBranch = GetFilesOfRepo(path);
+                Assert.NotEqual(filesInMain, filesInBranch);
+
+                repo.Reset(ResetMode.Hard);
+                repo.RemoveUntrackedFiles();
+
+                Assert.False(repo.RetrieveStatus().IsDirty);
+                filesInMain = GetFilesOfRepo(repoPath);
+                filesInBranch = GetFilesOfRepo(path);
+                Assert.Equal(filesInMain, filesInBranch);
+            }
+        }
+
+        [Fact]
+        public void CanAddWorktree_WithCommitedChanges()
+        {
+            var repoPath = SandboxWorktreeTestRepo();
+            using (var repo = new Repository(repoPath))
+            {
+                // stage all changes
+                Commands.Stage(repo, "*");
+                repo.Commit("Apply all changes", Constants.Signature, Constants.Signature);
+
+                Assert.Equal(2, repo.Worktrees.Count());
+
+                var name = "blah";
+                var path = Path.Combine(repo.Info.WorkingDirectory, "..", "worktrees", name);
+                var worktree = repo.Worktrees.Add(name, path, false);
+                Assert.Equal(name, worktree.Name);
+                Assert.False(worktree.IsLocked);
+
+                Assert.Equal(3, repo.Worktrees.Count());
+
+                // Check that branch contains same number of files and folders
+                // NOTE: There is an open bug - [Repository.Worktrees.Add leaves now worktree empty](https://github.com/libgit2/libgit2sharp/issues/2037)
+                Assert.False(repo.RetrieveStatus().IsDirty);
+                var filesInMain = GetFilesOfRepo(repoPath);
+                var filesInBranch = GetFilesOfRepo(path);
+                Assert.Equal(filesInMain, filesInBranch);
+            }
+        }
+
+        [Fact]
+        public void CanAddLockedWorktree_WithUncommitedChanges()
+        {
+            var repoPath = SandboxWorktreeTestRepo();
+            using (var repo = new Repository(repoPath))
+            {
+                Assert.Equal(2, repo.Worktrees.Count());
+
+                var name = "blah";
+                var path = Path.Combine(repo.Info.WorkingDirectory, "..", "worktrees", name);
+                var worktree = repo.Worktrees.Add(name, path, true);
+                Assert.Equal(name, worktree.Name);
+                Assert.True(worktree.IsLocked);
+
+                Assert.Equal(3, repo.Worktrees.Count());
+
+                // Check that branch contains same number of files and folders
+                // NOTE: There is an open bug - [Repository.Worktrees.Add leaves now worktree empty](https://github.com/libgit2/libgit2sharp/issues/2037)
+                Assert.True(repo.RetrieveStatus().IsDirty);
+                var filesInMain = GetFilesOfRepo(repoPath);
+                var filesInBranch = GetFilesOfRepo(path);
+                Assert.NotEqual(filesInMain, filesInBranch);
+
+                repo.Reset(ResetMode.Hard);
+                repo.RemoveUntrackedFiles();
+
+                Assert.False(repo.RetrieveStatus().IsDirty);
+                filesInMain = GetFilesOfRepo(repoPath);
+                filesInBranch = GetFilesOfRepo(path);
+                Assert.Equal(filesInMain, filesInBranch);
             }
         }
 
         [Fact]
-        public void CanAddLockedWorktree()
+        public void CanAddLockedWorktree_WithCommitedChanges()
         {
             var repoPath = SandboxWorktreeTestRepo();
             using (var repo = new Repository(repoPath))
             {
+                // stage all changes
+                Commands.Stage(repo, "*");
+                repo.Commit("Apply all changes", Constants.Signature, Constants.Signature);
+
                 Assert.Equal(2, repo.Worktrees.Count());
 
                 var name = "blah";
@@ -270,6 +349,13 @@ public void CanAddLockedWorktree()
                 Assert.True(worktree.IsLocked);
 
                 Assert.Equal(3, repo.Worktrees.Count());
+
+                // Check that branch contains same number of files and folders
+                // NOTE: There is an open bug - [Repository.Worktrees.Add leaves now worktree empty](https://github.com/libgit2/libgit2sharp/issues/2037)
+                Assert.False(repo.RetrieveStatus().IsDirty);
+                var filesInMain = GetFilesOfRepo(repoPath);
+                var filesInBranch = GetFilesOfRepo(path);
+                Assert.Equal(filesInMain, filesInBranch);
             }
         }
 
@@ -292,7 +378,22 @@ public void CanAddWorktreeForCommittish()
                     Assert.Equal(committish, repository.Head.FriendlyName);
                 }
                 Assert.Equal(3, repo.Worktrees.Count());
+
+                // Check that branch contains same number of files and folders
+                // NOTE: There is an open bug - [Repository.Worktrees.Add leaves now worktree empty](https://github.com/libgit2/libgit2sharp/issues/2037)
+                var filesInCommittish = new string[] { "numbers.txt", "super-file.txt" };
+                var filesInBranch = GetFilesOfRepo(path);
+                Assert.Equal(filesInCommittish, filesInBranch);
             }
         }
+
+        private static IEnumerable<string> GetFilesOfRepo(string repoPath)
+        {
+            return Directory.GetFiles(repoPath, "*", SearchOption.AllDirectories)
+                .Where(fileName => !fileName.StartsWith($"{repoPath}\\.git", StringComparison.InvariantCultureIgnoreCase))
+                .Select(fileName => fileName.Replace($"{repoPath}\\", "", StringComparison.InvariantCultureIgnoreCase))
+                .OrderBy(fileName => fileName, StringComparer.InvariantCultureIgnoreCase)
+                .ToList();
+        }
     }
 }

LibGit2Sharp/Core/GitWorktree.cs

@@ -1,7 +1,5 @@
 using System;
-using System.Collections.Generic;
 using System.Runtime.InteropServices;
-using System.Text;
 
 namespace LibGit2Sharp.Core
 {
@@ -38,7 +36,11 @@ internal class git_worktree_add_options
 
         public IntPtr @ref = IntPtr.Zero;
 
-        public GitCheckoutOpts checkoutOpts = new GitCheckoutOpts { version = 1 };
+        public GitCheckoutOpts checkoutOpts = new GitCheckoutOpts
+        {
+            version = 1,
+            checkout_strategy = CheckoutStrategy.GIT_CHECKOUT_FORCE
+        };
     }
 
     [StructLayout(LayoutKind.Sequential)]

LibGit2Sharp/WorktreeCollection.cs

@@ -4,9 +4,7 @@
 using System.Collections;
 using System.Collections.Generic;
 using System.Globalization;
-using System.IO;
 using System.Linq;
-using System.Text;
 
 namespace LibGit2Sharp
 {
@@ -48,22 +46,21 @@ public virtual Worktree this[string name]
         }
 
         /// <summary>
-        /// 
+        /// Creates a worktree from a committish or branch.
         /// </summary>
-        /// <param name="committishOrBranchSpec"></param>
-        /// <param name="name"></param>
-        /// <param name="path"></param>
+        /// <param name="committishOrBranchSpec">A committish or branch name./param>
+        /// <param name="name">Name of the worktree.</param>
+        /// <param name="path">Location of the worktree.</param>
         /// <param name="isLocked"></param>
-        /// <returns></returns>
         public virtual Worktree Add(string committishOrBranchSpec, string name, string path, bool isLocked)
         {
-            if(string.Equals(committishOrBranchSpec, name))
+            if (string.Equals(committishOrBranchSpec, name))
             {
                 // Proxy.git_worktree_add() creates a new branch of name = name, so if we want to checkout a given branch then the 'name' cannot be the same as the target branch
                 return null;
             }
 
-            git_worktree_add_options options = new git_worktree_add_options
+            var options = new git_worktree_add_options
             {
                 version = 1,
                 locked = Convert.ToInt32(isLocked)
@@ -83,20 +80,18 @@ public virtual Worktree Add(string committishOrBranchSpec, string name, string p
                 }
             }
 
-            
-
-            return this[name]; 
+            return this[name];
         }
 
         /// <summary>
-        /// 
+        /// Creates a worktree from a committish or branch.
         /// </summary>
-        /// <param name="name"></param>
-        /// <param name="path"></param>
-        /// <param name="isLocked"></param>
+        /// <param name="committishOrBranchSpec">A committish or branch name./param>
+        /// <param name="name">Name of the worktree.</param>
+        /// <param name="path">Location of the worktree.</param>
         public virtual Worktree Add(string name, string path, bool isLocked)
         {
-            git_worktree_add_options options = new git_worktree_add_options
+            var options = new git_worktree_add_options
             {
                 version = 1,
                 locked = Convert.ToInt32(isLocked)