From 9e1623cff4d96e4f8ebb4b6dc6b9292d5406a747 Mon Sep 17 00:00:00 2001
From: Artem Lytkin <iprintercanon@gmail.com>
Date: Sat, 5 Sep 2026 10:19:11 +0300
Subject: [PATCH] action: Keep the tab ID stable once the tab has splits

`Tab` embeds its root `views.Node`, so `tab:ID()` from Lua resolved to
`Node.ID()`, which returns 0 for any node that has children. As soon as
a tab contained a split its root stopped being a leaf and the id was
gone.

Give `Tab` its own id, taken from the root node when the tab is created,
so it stays the same after splitting. An unsplit tab reports the same
value as before.
---
 internal/action/tab.go      | 13 ++++++++++++
 internal/action/tab_test.go | 40 +++++++++++++++++++++++++++++++++++++
 2 files changed, 53 insertions(+)
 create mode 100644 internal/action/tab_test.go

diff --git a/internal/action/tab.go b/internal/action/tab.go
index e1672a9332..76c984da73 100644
--- a/internal/action/tab.go
+++ b/internal/action/tab.go
@@ -239,6 +239,11 @@ type Tab struct {
 	*views.Node
 	*display.UIWindow
 
+	// id is this tab's unique id. It is taken from the root node when the
+	// tab is created and does not change afterwards, unlike the id of the
+	// embedded root node, which becomes 0 once the node has children.
+	id uint64
+
 	isActive bool
 
 	Panes  []Pane
@@ -253,6 +258,7 @@ type Tab struct {
 func NewTabFromBuffer(x, y, width, height int, b *buffer.Buffer) *Tab {
 	t := new(Tab)
 	t.Node = views.NewRoot(x, y, width, height)
+	t.id = t.Node.ID()
 	t.UIWindow = display.NewUIWindow(t.Node)
 	t.release = true
 
@@ -266,6 +272,7 @@ func NewTabFromBuffer(x, y, width, height int, b *buffer.Buffer) *Tab {
 func NewTabFromPane(x, y, width, height int, pane Pane) *Tab {
 	t := new(Tab)
 	t.Node = views.NewRoot(x, y, width, height)
+	t.id = t.Node.ID()
 	t.UIWindow = display.NewUIWindow(t.Node)
 	t.release = true
 	pane.SetTab(t)
@@ -275,6 +282,12 @@ func NewTabFromPane(x, y, width, height int, pane Pane) *Tab {
 	return t
 }
 
+// ID returns this tab's unique id. Unlike the id of the tab's root node, it
+// stays the same after the tab has been split.
+func (t *Tab) ID() uint64 {
+	return t.id
+}
+
 // HandleEvent takes a tcell event and usually dispatches it to the current
 // active pane. However if the event is a resize or a mouse event where the user
 // is interacting with the UI (resizing splits) then the event is consumed here
diff --git a/internal/action/tab_test.go b/internal/action/tab_test.go
new file mode 100644
index 0000000000..88e6b198c0
--- /dev/null
+++ b/internal/action/tab_test.go
@@ -0,0 +1,40 @@
+package action
+
+import (
+	"testing"
+
+	"github.com/micro-editor/micro/v2/internal/buffer"
+	"github.com/micro-editor/micro/v2/internal/config"
+	ulua "github.com/micro-editor/micro/v2/internal/lua"
+	lua "github.com/yuin/gopher-lua"
+)
+
+func init() {
+	ulua.L = lua.NewState()
+	config.InitRuntimeFiles(false)
+	config.InitGlobalSettings()
+	config.GlobalSettings["backup"] = false
+	config.GlobalSettings["fastdirty"] = true
+}
+
+func newTestTab() *Tab {
+	return NewTabFromBuffer(0, 0, 80, 24, buffer.NewBufferFromString("", "", buffer.BTDefault))
+}
+
+func TestTabIDWithSplits(t *testing.T) {
+	tab1 := newTestTab()
+	tab2 := newTestTab()
+
+	id := tab1.ID()
+	if id == 0 {
+		t.Fatal("tab id is 0")
+	}
+	if tab2.ID() == id {
+		t.Fatalf("tabs share id %d", id)
+	}
+
+	tab1.VSplit(true)
+	if got := tab1.ID(); got != id {
+		t.Errorf("tab id changed from %d to %d after split", id, got)
+	}
+}