Re-apply the side panel config on a live config reload

When the config file changes and lazygit regains focus it reloads the
config, but the side panel window assignments, default views, tab
strips, and z-order were only ever set up on repo entry, so a changed
sidePanels wouldn't take effect until restart. Re-apply it from the
reload path: reassign windows and default views and restore each panel's
default tab.

The focused panel needs care: resetting it to its default tab would
leave the focused tab hidden behind that default tab, so the panel looks
unfocused even though its tab is selected. Re-focus the current context
so its tab stays shown and highlighted; only when the new config hides
the focused panel entirely do we move focus to the default side panel.
Tab strips are already refreshed via configureViewProperties.

pkg/gui/gui.go

@@ -357,6 +357,7 @@ func (gui *Gui) onNewRepo(startArgs appTypes.StartArgs, contextKey types.Context
 			if didChange && reloadErr == nil {
 				gui.c.Log.Info("User config changed - reloading")
 				reloadErr = gui.onUserConfigLoaded()
+				gui.reloadSidePanels()
 				if err := gui.resetKeybindings(); err != nil {
 					return err
 				}

pkg/gui/side_panels.go

@@ -3,6 +3,7 @@ package gui
 import (
 	"github.com/jesseduffield/lazygit/pkg/gui/context"
 	"github.com/jesseduffield/lazygit/pkg/gui/types"
+	"github.com/samber/lo"
 )
 
 // sidePanelViewNames maps each gui.sidePanels name to the gocui view it controls.
@@ -58,7 +59,8 @@ func sidePanelContexts(contextTree *context.ContextTree) map[string]types.Contex
 // applySidePanelConfig (re)assigns each side context's window and resets each
 // window's default view from the current gui.sidePanels config. It runs against
 // the current repo's contexts, so gui.State must already be set. We call it on
-// every repo entry (a repo's per-repo config can differ from the previous one's).
+// every repo entry (a repo's per-repo config can differ from the previous one's)
+// and on a live config reload.
 func (gui *Gui) applySidePanelConfig() {
 	contextTree := gui.State.Contexts
 	gui.assignSidePanelWindows(contextTree)
@@ -76,6 +78,31 @@ func (gui *Gui) moveDefaultTabsToTop() {
 	}
 }
 
+// reloadSidePanels re-applies the side panel config to the current repo after a
+// live config reload: it reassigns windows and default views, restores each
+// panel's default tab, and keeps the focused panel in a consistent state.
+func (gui *Gui) reloadSidePanels() {
+	gui.applySidePanelConfig()
+	gui.moveDefaultTabsToTop()
+
+	// applySidePanelConfig reset every window to show its first configured tab,
+	// which would leave the focused tab hidden behind its panel's default tab
+	// (the panel would look unfocused even though its tab is selected). Re-focus
+	// the current context so its tab stays shown and highlighted. If the new
+	// config has hidden the focused panel entirely, move focus to the default
+	// side panel instead.
+	current := gui.c.Context().Current()
+	if current.GetKind() != types.SIDE_CONTEXT {
+		return
+	}
+
+	if lo.Contains(gui.helpers.Window.SideWindows(), current.GetWindowName()) {
+		gui.c.Context().Activate(current, types.OnFocusOpts{})
+	} else {
+		gui.c.Context().Push(gui.defaultSideContext(), types.OnFocusOpts{})
+	}
+}
+
 // assignSidePanelWindows sets each side context's window name from the config so
 // that contexts grouped into one panel share a window (the window name being the
 // panel's first tab). Side panels the user hasn't listed get their own window

pkg/integration/tests/test_list.go

@@ -480,6 +480,7 @@ var tests = []*components.IntegrationTest{
 	ui.OpenLinkFailure,
 	ui.PromoteTabToSidePanel,
 	ui.RangeSelect,
+	ui.ReloadSidePanels,
 	ui.ReorderSidePanels,
 	ui.SwitchTabFromMenu,
 	ui.SwitchTabWithPanelJumpKeys,

pkg/integration/tests/ui/reload_side_panels.go

@@ -0,0 +1,51 @@
+package ui
+
+import (
+	"github.com/jesseduffield/lazygit/pkg/config"
+	. "github.com/jesseduffield/lazygit/pkg/integration/components"
+)
+
+var ReloadSidePanels = NewIntegrationTest(NewIntegrationTestArgs{
+	Description:  "Editing the side panel config and refocusing the window re-applies the layout live, keeping the focused panel focused",
+	ExtraCmdArgs: []string{},
+	Skip:         false,
+	SetupConfig:  func(cfg *config.AppConfig) {},
+	SetupRepo: func(shell *Shell) {
+		shell.CreateNCommits(2)
+		// Start with worktrees promoted to its own panel.
+		shell.CreateFile(".git/lazygit.yml", `
+gui:
+  sidePanels:
+    - [status]
+    - [files, submodules]
+    - [worktrees]
+    - [branches, remotes, tags]
+    - [commits, reflog]
+    - [stash]`)
+	},
+	Run: func(t *TestDriver, keys config.KeybindingConfig) {
+		// Worktrees is its own panel in the third position.
+		t.Views().Files().IsFocused().
+			Press(keys.Universal.JumpToBlock[2])
+		t.Views().Worktrees().IsFocused()
+
+		// Demote worktrees back into the files panel, then refocus the window to
+		// trigger a live reload of the changed config.
+		t.Shell().UpdateFile(".git/lazygit.yml", `
+gui:
+  sidePanels:
+    - [status]
+    - [files, worktrees, submodules]
+    - [branches, remotes, tags]
+    - [commits, reflog]
+    - [stash]`)
+		t.FocusIn()
+
+		// Worktrees is now a tab of the files panel. It stays focused, and is shown
+		// in front rather than being hidden behind the files tab (which would leave
+		// the panel looking unfocused).
+		t.Views().Worktrees().IsActiveTab().IsFocused().
+			Press(keys.Universal.PrevTab)
+		t.Views().Files().IsActiveTab().IsFocused()
+	},
+})