Fix visual glitches when moving a rebase todo

This fixes two problems:
1. the list selection updated before the list content did, which caused
a bit of a wobble effect in the list
2. the main view would first update to a different commit's diff and
then back to the one that is being moved, resulting in a very ugly
flicker especially when moving the todo multiple times with auto repeat

pkg/gui/context/simple_context.go

@@ -41,7 +41,7 @@ func (self *SimpleContext) HandleFocus(opts types.OnFocusOpts) {
 		fn(opts)
 	}
 
-	if self.onRenderToMainFn != nil {
+	if self.onRenderToMainFn != nil && !opts.SkipMainViewUpdate {
 		self.onRenderToMainFn()
 	}
 }

pkg/gui/controllers/helpers/refresh_helper.go

@@ -119,6 +119,9 @@ type refreshEnv struct {
 	// reload state (see RefreshOptions.DontBlockRepoSwitch).
 	keepScrollPosition bool
 
+	// Whether refreshing a side context should leave the main view unchanged.
+	skipMainViewUpdate bool
+
 	// the repo generation captured when the refresh started
 	generation int
 
@@ -231,6 +234,7 @@ func (self *RefreshHelper) performRefresh(options types.RefreshOptions, calledFr
 		background:         options.Background || options.DontBlockRepoSwitch,
 		backgroundRoutine:  options.Background,
 		keepScrollPosition: options.Background || options.DontBlockRepoSwitch,
+		skipMainViewUpdate: options.SkipMainViewUpdate,
 	}
 	if !self.captureOnUIThread(calledFromWorker, env.background, func() {
 		env.generation = self.c.State().GetRepoGeneration()
@@ -1672,6 +1676,7 @@ func (self *RefreshHelper) refreshView(context types.Context, env refreshEnv) {
 
 		self.c.PostRefreshUpdateWithOptions(context, types.OnFocusOpts{
 			KeepScrollPosition: env.keepScrollPosition,
+			SkipMainViewUpdate: env.skipMainViewUpdate,
 		})
 
 		self.c.AfterLayout(func() error {

pkg/gui/controllers/local_commits_controller.go

@@ -345,7 +345,9 @@ func (self *LocalCommitsController) startMovingCommitsIndicator(insertionIndex i
 func (self *LocalCommitsController) stopMovingCommitsIndicator() {
 	self.stopMovingCommitsIndicatorTicker()
 	self.context().ClearDropInsertionIndex()
-	self.c.PostRefreshUpdate(self.context())
+	self.c.PostRefreshUpdateWithOptions(
+		self.context(), types.OnFocusOpts{SkipMainViewUpdate: true},
+	)
 }
 
 func (self *LocalCommitsController) stopMovingCommitsIndicatorTicker() {
@@ -1171,15 +1173,21 @@ func (self *LocalCommitsController) move(
 		if err := self.c.Git().Rebase.MoveTodos(selectedCommits, offset); err != nil {
 			return err
 		}
-		self.context().MoveSelection(offset)
-		self.context().HandleFocus(types.OnFocusOpts{})
 
 		// Block input until the refresh has landed: a quick second press must
 		// read the moved todo from the refreshed model, not grab whatever the
 		// advanced selection index points at in the stale one.
 		self.c.RefreshBlockingInput(types.RefreshOptions{
-			Scope: []types.RefreshableView{types.REBASE_COMMITS},
-			Then:  onComplete,
+			Scope:              []types.RefreshableView{types.REBASE_COMMITS},
+			SkipMainViewUpdate: true,
+			Then: func() error {
+				self.context().MoveSelection(offset)
+				self.context().FocusLine(true)
+				if onComplete != nil {
+					return onComplete()
+				}
+				return nil
+			},
 		})
 		return nil
 	}

pkg/gui/types/context.go

@@ -234,6 +234,10 @@ type OnFocusOpts struct {
 	// the view's scroll position alone instead; only for callers that maintain
 	// it themselves, e.g. by keeping the selection at the edge of the viewport.
 	KeepScrollPosition bool
+
+	// Set this when the focused item hasn't changed and the main view's current
+	// content is still valid.
+	SkipMainViewUpdate bool
 }
 
 type OnFocusLostOpts struct {

pkg/gui/types/refresh.go

@@ -72,6 +72,10 @@ type RefreshOptions struct {
 	// letting each scope update the UI as soon as it's done.
 	BatchUIUpdates bool
 
+	// Set this when the refresh doesn't invalidate the main view's current
+	// content, so refreshing the side context needn't render it again.
+	SkipMainViewUpdate bool
+
 	// Controls which local branch is selected after the refresh. Defaults to
 	// KeepBranchSelectionByName.
 	BranchSelection BranchSelectionBehavior

pkg/gui/view_helpers.go

@@ -149,6 +149,9 @@ func (gui *Gui) postRefreshUpdate(c types.Context, opts types.OnFocusOpts) {
 		// correctly, and that integration tests see the up to date selection
 		// state.
 		c.FocusLine(!opts.KeepScrollPosition)
+		if opts.SkipMainViewUpdate {
+			return
+		}
 
 		currentCtx := gui.State.ContextMgr.Current()
 		if currentCtx.GetKey() == context.NORMAL_MAIN_CONTEXT_KEY || currentCtx.GetKey() == context.NORMAL_SECONDARY_CONTEXT_KEY {