Support bare worktrees where worktree does not have its own .git file

This was on oversight on my part: I assumed that the --work-tree arg was
always intended for use with linked worktrees which have a .git file
pointing back to the repo.

I'm honestly confused now: seems like there are three kinds of worktrees:
* the main worktree of a non-bare repo
* a linked worktree (with its own gitdir in the repo's worktrees/ dir)
* a random folder which you specify as a worktree with the --work-tree arg

I'm pretty sure the --work-tree arg is only intended to be used with this
third kind or workree

pkg/app/entry_point.go

@@ -63,8 +63,17 @@ func Start(buildInfo *BuildInfo, integrationTest integrationTypes.IntegrationTes
 			log.Fatal(absRepoPath + " is not a valid git repository.")
 		}
 
-		cliArgs.WorkTree = absRepoPath
 		cliArgs.GitDir = filepath.Join(absRepoPath, ".git")
+		err = os.Chdir(absRepoPath)
+		if err != nil {
+			log.Fatalf("Failed to change directory to %s: %v", absRepoPath, err)
+		}
+	} else if cliArgs.WorkTree != "" {
+		env.SetWorkTreeEnv(cliArgs.WorkTree)
+
+		if err := os.Chdir(cliArgs.WorkTree); err != nil {
+			log.Fatalf("Failed to change directory to %s: %v", cliArgs.WorkTree, err)
+		}
 	}
 
 	if cliArgs.CustomConfigFile != "" {
@@ -75,13 +84,6 @@ func Start(buildInfo *BuildInfo, integrationTest integrationTypes.IntegrationTes
 		os.Setenv("CONFIG_DIR", cliArgs.UseConfigDir)
 	}
 
-	if cliArgs.WorkTree != "" {
-		err := os.Chdir(cliArgs.WorkTree)
-		if err != nil {
-			log.Fatalf("Failed to change directory to %s: %v", cliArgs.WorkTree, err)
-		}
-	}
-
 	if cliArgs.GitDir != "" {
 		env.SetGitDirEnv(cliArgs.GitDir)
 	}
@@ -118,12 +120,6 @@ func Start(buildInfo *BuildInfo, integrationTest integrationTypes.IntegrationTes
 		os.Exit(0)
 	}
 
-	if cliArgs.WorkTree != "" {
-		if err := os.Chdir(cliArgs.WorkTree); err != nil {
-			log.Fatal(err.Error())
-		}
-	}
-
 	tempDir, err := os.MkdirTemp("", "lazygit-*")
 	if err != nil {
 		log.Fatal(err.Error())

pkg/commands/git_commands/repo_paths.go

@@ -91,10 +91,24 @@ func getRepoPathsAux(
 	if err != nil {
 		return nil, errors.Errorf("failed to get repo git dir path: %v", err)
 	}
-	worktreeGitDirPath, err := worktreeGitDirPath(fs, currentPath)
+
+	var worktreeGitDirPath string
+	if env.GetWorkTreeEnv() != "" {
+		// This env is set when you pass --work-tree to lazygit. In that case,
+		// we're not dealing with a linked work-tree, we're dealing with a 'specified'
+		// worktree (for lack of a better term). In this case, the worktree has no
+		// .git file and it just contains a bunch of files: it has no idea it's
+		// pointed to by a bare repo. As such it does not have its own git dir within
+		// the bare repo's git dir. Instead, we just use the bare repo's git dir.
+		worktreeGitDirPath = repoGitDirPath
+	} else {
+		var err error
+		worktreeGitDirPath, err = getWorktreeGitDirPath(fs, currentPath)
 		if err != nil {
 			return nil, errors.Errorf("failed to get worktree git dir path: %v", err)
 		}
+	}
+
 	repoName := path.Base(repoPath)
 
 	return &RepoPaths{
@@ -110,7 +124,7 @@ func getRepoPathsAux(
 // Returns the path of the git-dir for the worktree. For linked worktrees, the worktree has
 // a .git file that points to the git-dir (which itself lives in the git-dir
 // of the repo)
-func worktreeGitDirPath(fs afero.Fs, worktreePath string) (string, error) {
+func getWorktreeGitDirPath(fs afero.Fs, worktreePath string) (string, error) {
 	// if .git is a file, we're in a linked worktree, otherwise we're in
 	// the main worktree
 	dotGitPath := path.Join(worktreePath, ".git")

pkg/commands/git_commands/worktree_loader.go

@@ -58,7 +58,7 @@ func (self *WorktreeLoader) GetWorktrees() ([]*models.Worktree, error) {
 			isPathMissing := self.pathExists(path)
 
 			var gitDir string
-			gitDir, err := worktreeGitDirPath(self.Fs, path)
+			gitDir, err := getWorktreeGitDirPath(self.Fs, path)
 			if err != nil {
 				self.Log.Warnf("Could not find git dir for worktree %s: %v", path, err)
 			}

pkg/env/env.go

@@ -14,6 +14,15 @@ func SetGitDirEnv(value string) {
 	os.Setenv("GIT_DIR", value)
 }
 
-func UnsetGitDirEnv() {
-	_ = os.Unsetenv("GIT_DIR")
+func GetWorkTreeEnv() string {
+	return os.Getenv("GIT_WORK_TREE")
+}
+
+func SetWorkTreeEnv(value string) {
+	os.Setenv("GIT_WORK_TREE", value)
+}
+
+func UnsetGitLocationEnvVars() {
+	_ = os.Unsetenv("GIT_DIR")
+	_ = os.Unsetenv("GIT_WORK_TREE")
 }

pkg/gui/controllers/helpers/repos_helper.go

@@ -145,7 +145,7 @@ func (self *ReposHelper) DispatchSwitchToRepo(path string, contextKey types.Cont
 
 func (self *ReposHelper) DispatchSwitchTo(path string, errMsg string, contextKey types.ContextKey) error {
 	return self.c.WithWaitingStatus(self.c.Tr.Switching, func(gocui.Task) error {
-		env.UnsetGitDirEnv()
+		env.UnsetGitLocationEnvVars()
 		originalPath, err := os.Getwd()
 		if err != nil {
 			return nil

pkg/integration/tests/worktree/dotfile_bare_repo.go

@@ -11,7 +11,7 @@ import (
 var DotfileBareRepo = NewIntegrationTest(NewIntegrationTestArgs{
 	Description:  "Open lazygit in the worktree of a dotfile bare repo and add a file and commit",
 	ExtraCmdArgs: []string{"--git-dir={{.actualPath}}/.bare", "--work-tree={{.actualPath}}/repo"},
-	Skip:         true,
+	Skip:         false,
 	// passing this because we're explicitly passing --git-dir and --work-tree args
 	UseCustomPath: true,
 	SetupConfig:   func(config *config.AppConfig) {},