Bounce BRANCHES model updates onto the UI thread

refreshBranches now loads the branches (and worktrees) on the worker and
writes Model.Branches, the pull-requests map, Model.Worktrees, and the
restored branch selection in an onUIThreadUnlessRepoChanged bounce. The
selection restore and rebuildPullRequestsMap run in the bounce so they
see the branches we just wrote; the LocalCommits re-render (for branch
head visualization) moves into the same bounce.

refreshStatus is adjusted to read the checked-out branch and the linked
worktree name inside its bounce rather than on the worker: both derive
from models (Branches, Worktrees) that are now written via bounces, so
reading them on the worker would format the status from stale values —
which showed up as the status line dropping the "(worktree)" suffix right
after entering a submodule or switching worktrees. The git work
(WorkingTreeState) stays on the worker.

Two callers that read the branches model right after a SYNC branches
refresh move their reads into Then:
- BranchesHelper.PostFetchRefresh: AutoForwardBranches reads Model.Branches,
  so it runs in Then (preserving that a fetch error is still returned to
  the caller and that background auto-forward errors aren't surfaced as a
  popup).
- BranchesController rename: the re-select-by-name loop runs in Then.

RefreshingBranchesMutex is left in place for the mutex cleanup.

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

pkg/gui/controllers/branches_controller.go

@@ -783,20 +783,25 @@ func (self *BranchesController) rename(branch *models.Branch) error {
 					return err
 				}
 
-				// need to find where the branch is now so that we can re-select it. That means we need to refetch the branches synchronously and then find our branch
+				// need to find where the branch is now so that we can re-select it. That means we need to
+				// refetch the branches and then find our branch. The branches model update is bounced
+				// onto the UI thread, so the re-selection (which reads Model.Branches) has to run in
+				// Then; reading it inline here would see the previous model.
 				self.c.Refresh(types.RefreshOptions{
 					Mode:  types.SYNC,
 					Scope: []types.RefreshableView{types.BRANCHES, types.WORKTREES},
+					Then: func() error {
+						// now that we've got our stuff again we need to find that branch and reselect it.
+						for i, newBranch := range self.c.Model().Branches {
+							if newBranch.Name == newBranchName {
+								self.context().SetSelection(i)
+								self.context().HandleRender()
+							}
+						}
+						return nil
+					},
 				})
 
-				// now that we've got our stuff again we need to find that branch and reselect it.
-				for i, newBranch := range self.c.Model().Branches {
-					if newBranch.Name == newBranchName {
-						self.context().SetSelection(i)
-						self.context().HandleRender()
-					}
-				}
-
 				return nil
 			},
 		})

pkg/gui/controllers/helpers/branches_helper.go

@@ -387,11 +387,28 @@ func (self *BranchesHelper) PostFetchRefresh(fetchErr error, background bool) er
 	if self.c.UserConfig().Git.AutoForwardBranches != "none" {
 		scope = append(scope, types.WORKTREES)
 	}
-	self.c.Refresh(types.RefreshOptions{Scope: scope, Mode: types.SYNC, Background: background})
-	if fetchErr != nil {
-		return fetchErr
-	}
-	return self.AutoForwardBranches()
+	// AutoForwardBranches reads Model.Branches, which the branches refresh writes
+	// via a bounce, so it has to run in Then rather than right after Refresh
+	// returns (where it would still see the previous branches).
+	self.c.Refresh(types.RefreshOptions{
+		Scope:      scope,
+		Mode:       types.SYNC,
+		Background: background,
+		Then: func() error {
+			if fetchErr != nil {
+				return nil
+			}
+			err := self.AutoForwardBranches()
+			if background && err != nil {
+				// The background poller discards this return value, so surface
+				// the error in the log rather than as a popup for background work.
+				self.c.Log.Error(err)
+				return nil
+			}
+			return err
+		},
+	})
+	return fetchErr
 }
 
 func (self *BranchesHelper) AutoForwardBranches() error {

pkg/gui/controllers/helpers/refresh_helper.go

@@ -742,6 +742,8 @@ func (self *RefreshHelper) refreshBranches(refreshWorktrees bool, keepBranchSele
 	self.c.Mutexes().RefreshingBranchesMutex.Lock()
 	defer self.c.Mutexes().RefreshingBranchesMutex.Unlock()
 
+	generation := self.c.State().GetRepoGeneration()
+
 	branches, err := self.c.Git().Loaders.BranchLoader.Load(
 		reflogCommits,
 		self.c.Model().MainBranches,
@@ -753,7 +755,7 @@ func (self *RefreshHelper) refreshBranches(refreshWorktrees bool, keepBranchSele
 			})
 		},
 		func() {
-			self.c.OnUIThread(func() error {
+			self.onUIThreadUnlessRepoChanged(generation, func() error {
 				self.c.Contexts().Branches.HandleRender()
 				self.refreshStatus()
 				return nil
@@ -765,38 +767,42 @@ func (self *RefreshHelper) refreshBranches(refreshWorktrees bool, keepBranchSele
 
 	prevSelectedBranch := self.c.Contexts().Branches.GetSelected()
 
-	self.c.Model().Branches = branches
-	self.rebuildPullRequestsMap()
-
+	var worktrees []*models.Worktree
 	if refreshWorktrees {
-		// TODO: this synchronous worker write goes away when refreshBranches is
-		// itself migrated to bouncing; for now it matches the rest of this
-		// not-yet-bounced function.
-		self.c.Model().Worktrees = self.loadWorktrees()
-		self.refreshView(self.c.Contexts().Worktrees)
+		worktrees = self.loadWorktrees()
 	}
 
-	if !keepBranchSelectionIndex && prevSelectedBranch != nil {
-		self.searchHelper.ReApplyFilter(self.c.Contexts().Branches)
+	self.onUIThreadUnlessRepoChanged(generation, func() error {
+		self.c.Model().Branches = branches
+		// Rebuilding here (rather than on the worker) means the map is built from
+		// the branches we just wrote, on the UI thread.
+		self.rebuildPullRequestsMap()
 
-		_, idx, found := lo.FindIndexOf(self.c.Contexts().Branches.GetItems(),
-			func(b *models.Branch) bool { return b.Name == prevSelectedBranch.Name })
-		if found {
-			self.c.Contexts().Branches.SetSelectedLineIdx(idx)
+		if refreshWorktrees {
+			self.c.Model().Worktrees = worktrees
+			self.refreshView(self.c.Contexts().Worktrees)
 		}
-	}
 
-	self.refreshView(self.c.Contexts().Branches)
+		if !keepBranchSelectionIndex && prevSelectedBranch != nil {
+			self.searchHelper.ReApplyFilter(self.c.Contexts().Branches)
 
-	// Need to re-render the commits view because the visualization of local
-	// branch heads might have changed
-	self.c.OnUIThread(func() error {
+			_, idx, found := lo.FindIndexOf(self.c.Contexts().Branches.GetItems(),
+				func(b *models.Branch) bool { return b.Name == prevSelectedBranch.Name })
+			if found {
+				self.c.Contexts().Branches.SetSelectedLineIdx(idx)
+			}
+		}
+
+		// Need to re-render the commits view because the visualization of local
+		// branch heads might have changed
 		self.c.Mutexes().LocalCommitsMutex.Lock()
 		self.c.Contexts().LocalCommits.HandleRender()
 		self.c.Mutexes().LocalCommitsMutex.Unlock()
 		return nil
 	})
 
+	self.refreshView(self.c.Contexts().Branches)
+
 	self.refreshStatus()
 }
 
@@ -1074,20 +1080,22 @@ func (self *RefreshHelper) refreshStatus() {
 
 	generation := self.c.State().GetRepoGeneration()
 
-	currentBranch := self.refsHelper.GetCheckedOutRef()
-	if currentBranch == nil {
-		// need to wait for branches to refresh
-		return
-	}
-
 	workingTreeState := self.c.Git().Status.WorkingTreeState()
-	linkedWorktreeName := self.worktreeHelper.GetLinkedWorktreeName()
-
 	repoName := self.c.Git().RepoPaths.RepoName()
 
-	status := presentation.FormatStatus(repoName, currentBranch, types.ItemOperationNone, linkedWorktreeName, workingTreeState, self.c.Tr, self.c.UserConfig())
-
 	self.onUIThreadUnlessRepoChanged(generation, func() error {
+		// Read the checked-out branch and the linked worktree name here on the UI
+		// thread: both derive from models (Branches, Worktrees) that their
+		// refreshes now write via bounces, so reading them on the worker would
+		// see stale values from before those bounces applied.
+		currentBranch := self.refsHelper.GetCheckedOutRef()
+		if currentBranch == nil {
+			// need to wait for branches to refresh
+			return nil
+		}
+		linkedWorktreeName := self.worktreeHelper.GetLinkedWorktreeName()
+
+		status := presentation.FormatStatus(repoName, currentBranch, types.ItemOperationNone, linkedWorktreeName, workingTreeState, self.c.Tr, self.c.UserConfig())
 		self.c.SetViewContent(self.c.Views().Status, status)
 		return nil
 	})