Remove RefreshingFilesMutex/FileTreeViewModel.RWMutex, dead code

FileTreeViewModel.RWMutex is removed along with the
withFileTreeViewModelMutex wrapper in FilesController that RLocked it:
every writer (the bounce closure, previous commit) and every reader (key
handlers, disabled-reason callbacks) now runs on the UI thread, so the
mutex is redundant.

RefreshingFilesMutex is removed entirely, including its last use in
repos_helper's DispatchSwitchTo. That use predates the bounce and was
never about FilesController's optimistic-rendering concern; it serialized
a repo switch's onNewRepo() against an in-flight FILES refresh for the
repo being switched away from, so that a slow refresh from the old repo
couldn't write into the freshly-reset model for the new one. Bouncing the
write already broke that guarantee on its own terms — the mutex's critical
section never covered the bounced closure's actual execution, only the
(now-removed) code that enqueued it — so by this point it was only still
locked here without protecting anything real; the previous commit's
repo-generation guard is what now actually closes that race, making this
lock fully redundant rather than just relocated.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

pkg/gui/controllers/files_controller.go

@@ -44,7 +44,7 @@ func (self *FilesController) GetKeybindings(opts types.KeybindingsOpts) []*types
 		{
 			Keys:              opts.GetKeys(opts.Config.Universal.Select),
 			Handler:           self.withItems(self.press),
-			GetDisabledReason: self.require(self.withFileTreeViewModelMutex(self.itemsSelected(self.canStageSelection))),
+			GetDisabledReason: self.require(self.itemsSelected(self.canStageSelection)),
 			Description:       self.c.Tr.Stage,
 			Tooltip:           self.c.Tr.StageTooltip,
 			DisplayOnScreen:   true,
@@ -91,7 +91,7 @@ func (self *FilesController) GetKeybindings(opts types.KeybindingsOpts) []*types
 		{
 			Keys:              opts.GetKeys(opts.Config.Universal.Edit),
 			Handler:           self.withItems(self.edit),
-			GetDisabledReason: self.require(self.withFileTreeViewModelMutex(self.itemsSelected(self.canEditFiles))),
+			GetDisabledReason: self.require(self.itemsSelected(self.canEditFiles)),
 			Description:       self.c.Tr.Edit,
 			Tooltip:           self.c.Tr.EditFileTooltip,
 			DisplayOnScreen:   true,
@@ -145,7 +145,7 @@ func (self *FilesController) GetKeybindings(opts types.KeybindingsOpts) []*types
 		{
 			Keys:              opts.GetKeys(opts.Config.Universal.Remove),
 			Handler:           self.withItems(self.remove),
-			GetDisabledReason: self.withFileTreeViewModelMutex(self.require(self.itemsSelected(self.canRemove))),
+			GetDisabledReason: self.require(self.itemsSelected(self.canRemove)),
 			Description:       self.c.Tr.Discard,
 			Tooltip:           self.c.Tr.DiscardFileChangesTooltip,
 			OpensMenu:         true,
@@ -182,7 +182,7 @@ func (self *FilesController) GetKeybindings(opts types.KeybindingsOpts) []*types
 			Handler:           self.withItems(self.openMergeConflictMenu),
 			Description:       self.c.Tr.ViewMergeConflictOptions,
 			Tooltip:           self.c.Tr.ViewMergeConflictOptionsTooltip,
-			GetDisabledReason: self.require(self.withFileTreeViewModelMutex(self.itemsSelected(self.canOpenMergeConflictMenu))),
+			GetDisabledReason: self.require(self.itemsSelected(self.canOpenMergeConflictMenu)),
 			OpensMenu:         true,
 			DisplayOnScreen:   true,
 		},
@@ -209,15 +209,6 @@ func (self *FilesController) GetKeybindings(opts types.KeybindingsOpts) []*types
 	}
 }
 
-func (self *FilesController) withFileTreeViewModelMutex(callback func() *types.DisabledReason) func() *types.DisabledReason {
-	return func() *types.DisabledReason {
-		self.c.Contexts().Files.FileTreeViewModel.RWMutex.RLock()
-		defer self.c.Contexts().Files.FileTreeViewModel.RWMutex.RUnlock()
-
-		return callback()
-	}
-}
-
 func (self *FilesController) GetMouseKeybindings(opts types.KeybindingsOpts) []*gocui.ViewMouseBinding {
 	return []*gocui.ViewMouseBinding{
 		{
@@ -574,11 +565,6 @@ func (self *FilesController) toggleStaged(
 }
 
 func (self *FilesController) pressWithLock(selectedNodes []*filetree.FileNode) error {
-	// Obtaining this lock because optimistic rendering requires us to mutate
-	// the files in our model.
-	self.c.Mutexes().RefreshingFilesMutex.Lock()
-	defer self.c.Mutexes().RefreshingFilesMutex.Unlock()
-
 	// When filtering, expand directory nodes to individual visible file paths
 	// so that only filtered files are staged/unstaged.
 	toPaths := func(nodes []*filetree.FileNode) []string {
@@ -942,9 +928,6 @@ func (self *FilesController) toggleStagedAll() error {
 }
 
 func (self *FilesController) toggleStagedAllWithLock() error {
-	self.c.Mutexes().RefreshingFilesMutex.Lock()
-	defer self.c.Mutexes().RefreshingFilesMutex.Unlock()
-
 	root := self.context().FileTreeViewModel.GetRoot()
 
 	stage := func(unstagedNodes []*filetree.FileNode) error {

pkg/gui/controllers/helpers/refresh_helper.go

@@ -740,9 +740,6 @@ func (self *RefreshHelper) refreshBranches(refreshWorktrees bool, keepBranchSele
 }
 
 func (self *RefreshHelper) refreshFilesAndSubmodules(background bool) error {
-	self.c.Mutexes().RefreshingFilesMutex.Lock()
-	defer self.c.Mutexes().RefreshingFilesMutex.Unlock()
-
 	configs, err := self.refreshStateSubmoduleConfigs()
 	if err != nil {
 		return err

pkg/gui/controllers/helpers/repos_helper.go

@@ -177,9 +177,6 @@ func (self *ReposHelper) DispatchSwitchTo(path string, errMsg string, contextKey
 			self.c.Log.Errorf("error recording current directory: %v", err)
 		}
 
-		self.c.Mutexes().RefreshingFilesMutex.Lock()
-		defer self.c.Mutexes().RefreshingFilesMutex.Unlock()
-
 		if err := self.onNewRepo(appTypes.StartArgs{}, contextKey); err != nil {
 			return err
 		}

pkg/gui/filetree/file_tree_view_model.go

@@ -2,7 +2,6 @@ package filetree
 
 import (
 	"strings"
-	"sync"
 
 	"github.com/jesseduffield/lazygit/pkg/commands/models"
 	"github.com/jesseduffield/lazygit/pkg/common"
@@ -22,7 +21,6 @@ type IFileTreeViewModel interface {
 // which item is selected. It also contains logic for repositioning that cursor
 // after the files are refreshed
 type FileTreeViewModel struct {
-	sync.RWMutex
 	types.IListCursor
 	IFileTree
 	searchHistory *utils.HistoryBuffer[string]

pkg/gui/types/common.go

@@ -338,7 +338,6 @@ type Model struct {
 }
 
 type Mutexes struct {
-	RefreshingFilesMutex        deadlock.Mutex
 	RefreshingBranchesMutex     deadlock.Mutex
 	RefreshingStatusMutex       deadlock.Mutex
 	RefreshingPullRequestsMutex deadlock.Mutex