Add "Duplicate Tab" functionality

include/ghostty.h

@@ -737,6 +737,7 @@ typedef enum {
   GHOSTTY_ACTION_QUIT,
   GHOSTTY_ACTION_NEW_WINDOW,
   GHOSTTY_ACTION_NEW_TAB,
+  GHOSTTY_ACTION_DUPLICATE_TAB,
   GHOSTTY_ACTION_CLOSE_TAB,
   GHOSTTY_ACTION_NEW_SPLIT,
   GHOSTTY_ACTION_CLOSE_ALL_WINDOWS,

macos/Sources/App/macOS/AppDelegate.swift

@@ -28,6 +28,7 @@ class AppDelegate: NSObject,
 
     @IBOutlet private var menuNewWindow: NSMenuItem?
     @IBOutlet private var menuNewTab: NSMenuItem?
+    @IBOutlet private var menuDuplicateTab: NSMenuItem?
     @IBOutlet private var menuSplitRight: NSMenuItem?
     @IBOutlet private var menuSplitLeft: NSMenuItem?
     @IBOutlet private var menuSplitDown: NSMenuItem?
@@ -228,6 +229,11 @@ class AppDelegate: NSObject,
             selector: #selector(ghosttyNewTab(_:)),
             name: Ghostty.Notification.ghosttyNewTab,
             object: nil)
+        NotificationCenter.default.addObserver(
+            self,
+            selector: #selector(ghosttyDuplicateTab(_:)),
+            name: Ghostty.Notification.ghosttyDuplicateTab,
+            object: nil)
 
         // Configure user notifications
         let actions = [
@@ -522,6 +528,7 @@ class AppDelegate: NSObject,
         self.menuSecureInput?.setImageIfDesired(systemSymbolName: "lock.display")
         self.menuNewWindow?.setImageIfDesired(systemSymbolName: "macwindow.badge.plus")
         self.menuNewTab?.setImageIfDesired(systemSymbolName: "macwindow")
+        self.menuDuplicateTab?.setImageIfDesired(systemSymbolName: "plus.rectangle.on.rectangle")
         self.menuSplitRight?.setImageIfDesired(systemSymbolName: "rectangle.righthalf.inset.filled")
         self.menuSplitLeft?.setImageIfDesired(systemSymbolName: "rectangle.leadinghalf.inset.filled")
         self.menuSplitUp?.setImageIfDesired(systemSymbolName: "rectangle.tophalf.inset.filled")
@@ -563,6 +570,7 @@ class AppDelegate: NSObject,
 
         syncMenuShortcut(config, action: "new_window", menuItem: self.menuNewWindow)
         syncMenuShortcut(config, action: "new_tab", menuItem: self.menuNewTab)
+        syncMenuShortcut(config, action: "duplicate_tab", menuItem: self.menuDuplicateTab)
         syncMenuShortcut(config, action: "close_surface", menuItem: self.menuClose)
         syncMenuShortcut(config, action: "close_tab", menuItem: self.menuCloseTab)
         syncMenuShortcut(config, action: "close_window", menuItem: self.menuCloseWindow)
@@ -782,6 +790,20 @@ class AppDelegate: NSObject,
         _ = TerminalController.newTab(ghostty, from: window, withBaseConfig: config)
     }
 
+    @objc private func ghosttyDuplicateTab(_ notification: Notification) {
+        guard let surfaceView = notification.object as? Ghostty.SurfaceView else { return }
+        guard let window = surfaceView.window else { return }
+
+        // We only want to listen to duplicate tabs if the focused parent is
+        // a regular terminal controller.
+        guard window.windowController is TerminalController else { return }
+
+        let configAny = notification.userInfo?[Ghostty.Notification.NewSurfaceConfigKey]
+        let config = configAny as? Ghostty.SurfaceConfiguration
+
+        _ = TerminalController.duplicateTab(ghostty, from: window, withBaseConfig: config)
+    }
+
     private func setDockBadge(_ label: String? = "•") {
         NSApp.dockTile.badgeLabel = label
         NSApp.dockTile.display()
@@ -1015,6 +1037,10 @@ class AppDelegate: NSObject,
         _ = TerminalController.newTab(ghostty)
     }
 
+    @IBAction func duplicateTab(_ sender: Any?) {
+        _ = TerminalController.duplicateTab(ghostty)
+    }
+
     @IBAction func closeAllWindows(_ sender: Any?) {
         TerminalController.closeAllWindows()
         AboutController.shared.hide()
@@ -1167,6 +1193,14 @@ extension AppDelegate: NSMenuItemValidation {
             // terminal window (not quick terminal).
             return NSApp.keyWindow is TerminalWindow
 
+        case #selector(duplicateTab(_:)):
+            // Only enable duplicate tab if there's a focused surface in the key window
+            guard let keyWindow = NSApp.keyWindow,
+                  let controller = keyWindow.windowController as? TerminalController else {
+                return false
+            }
+            return controller.focusedSurface != nil
+
         case #selector(undo(_:)):
             if undoManager.canUndo {
                 item.title = "Undo \(undoManager.undoActionName)"

macos/Sources/App/macOS/MainMenu.xib

@@ -1,8 +1,8 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<document type="com.apple.InterfaceBuilder3.Cocoa.XIB" version="3.0" toolsVersion="24123.1" targetRuntime="MacOSX.Cocoa" propertyAccessControl="none" useAutolayout="YES" customObjectInstantitationMethod="direct">
+<document type="com.apple.InterfaceBuilder3.Cocoa.XIB" version="3.0" toolsVersion="24127" targetRuntime="MacOSX.Cocoa" propertyAccessControl="none" useAutolayout="YES" customObjectInstantitationMethod="direct">
     <dependencies>
         <deployment identifier="macosx"/>
-        <plugIn identifier="com.apple.InterfaceBuilder.CocoaPlugin" version="24123.1"/>
+        <plugIn identifier="com.apple.InterfaceBuilder.CocoaPlugin" version="24127"/>
     </dependencies>
     <objects>
         <customObject id="-2" userLabel="File's Owner" customClass="NSApplication">
@@ -25,6 +25,7 @@
                 <outlet property="menuCommandPalette" destination="et6-de-Mh7" id="53t-cu-dm5"/>
                 <outlet property="menuCopy" destination="Jqf-pv-Zcu" id="bKd-1C-oy9"/>
                 <outlet property="menuDecreaseFontSize" destination="kzb-SZ-dOA" id="Y1B-Vh-6Z2"/>
+                <outlet property="menuDuplicateTab" destination="34s-0R-Gru" id="dKE-du-Nrz"/>
                 <outlet property="menuEqualizeSplits" destination="3gH-VD-vL9" id="SiZ-ce-FOF"/>
                 <outlet property="menuFloatOnTop" destination="uRj-7z-1Nh" id="94n-o9-Jol"/>
                 <outlet property="menuIncreaseFontSize" destination="CIH-ey-Z6x" id="hkc-9C-80E"/>
@@ -150,6 +151,12 @@
                                     <action selector="newTab:" target="-1" id="KoW-K7-hw5"/>
                                 </connections>
                             </menuItem>
+                            <menuItem title="Duplicate Tab" id="34s-0R-Gru" userLabel="Duplicate Tab">
+                                <modifierMask key="keyEquivalentModifierMask"/>
+                                <connections>
+                                    <action selector="duplicateTab:" target="-1" id="Bjj-AY-W2r"/>
+                                </connections>
+                            </menuItem>
                             <menuItem isSeparatorItem="YES" id="m54-Is-iLE"/>
                             <menuItem title="Split Right" id="VUR-Ld-nLx">
                                 <modifierMask key="keyEquivalentModifierMask"/>

macos/Sources/Features/QuickTerminal/QuickTerminalController.swift

@@ -79,6 +79,11 @@ class QuickTerminalController: BaseTerminalController {
             selector: #selector(onNewTab),
             name: Ghostty.Notification.ghosttyNewTab,
             object: nil)
+        center.addObserver(
+            self,
+            selector: #selector(onDuplicateTab),
+            name: Ghostty.Notification.ghosttyDuplicateTab,
+            object: nil)
         center.addObserver(
             self,
             selector: #selector(windowDidResize(_:)),
@@ -588,6 +593,10 @@ class QuickTerminalController: BaseTerminalController {
     @IBAction func newTab(_ sender: Any?) {
         showNoNewTabAlert()
     }
+
+    @IBAction func duplicateTab(_ sender: Any?) {
+        showNoNewTabAlert()
+    }
 
     @IBAction func toggleGhosttyFullScreen(_ sender: Any) {
         guard let surface = focusedSurface?.surface else { return }
@@ -659,6 +668,14 @@ class QuickTerminalController: BaseTerminalController {
         // Tabs aren't supported with Quick Terminals or derivatives
         showNoNewTabAlert()
     }
+
+    @objc private func onDuplicateTab(notification: SwiftUI.Notification) {
+        guard let surfaceView = notification.object as? Ghostty.SurfaceView else { return }
+        guard let window = surfaceView.window else { return }
+        guard window.windowController is QuickTerminalController else { return }
+        // Tabs aren't supported with Quick Terminals or derivatives
+        showNoNewTabAlert()
+    }
 
     private struct DerivedConfig {
         let quickTerminalScreen: QuickTerminalScreen

macos/Sources/Features/Terminal/TerminalController.swift

@@ -388,6 +388,28 @@ class TerminalController: BaseTerminalController, TabGroupCloseCoordinator.Contr
         return controller
     }
 
+    static func duplicateTab(
+        _ ghostty: Ghostty.App,
+        from parent: NSWindow? = nil,
+        withBaseConfig baseConfig: Ghostty.SurfaceConfiguration? = nil
+    ) -> TerminalController? {
+        let parentWindow = parent ?? NSApp.keyWindow
+
+        guard let parentWindow = parentWindow,
+              let parentController = parentWindow.windowController as? TerminalController else {
+            return newWindow(ghostty, withBaseConfig: baseConfig, withParent: parent)
+        }
+
+        var config = baseConfig ?? Ghostty.SurfaceConfiguration()
+
+        if let focusedSurface = parentController.focusedSurface,
+           let workingDirectory = focusedSurface.pwd {
+            config.workingDirectory = workingDirectory
+        }
+
+        return newTab(ghostty, from: parentWindow, withBaseConfig: config)
+    }
+
     //MARK: - Methods
 
     @objc private func ghosttyConfigDidChange(_ notification: Notification) {
@@ -1057,6 +1079,14 @@ class TerminalController: BaseTerminalController, TabGroupCloseCoordinator.Contr
         ghostty.newTab(surface: surface)
     }
 
+    @IBAction func duplicateTab(_ sender: Any?) {
+        _ = TerminalController.duplicateTab(
+            ghostty,
+            from: window,
+            withBaseConfig: Ghostty.SurfaceConfiguration()
+        )
+    }
+
     @IBAction func closeTab(_ sender: Any?) {
         guard let window = window else { return }
         guard window.tabGroup?.windows.count ?? 0 > 1 else {

macos/Sources/Ghostty/Ghostty.App.swift

@@ -187,6 +187,13 @@ extension Ghostty {
             }
         }
 
+        func duplicateTab(surface: ghostty_surface_t) {
+            let action = "duplicate_tab"
+            if (!ghostty_surface_binding_action(surface, action, UInt(action.count))) {
+                logger.warning("action failed action=\(action)")
+            }
+        }
+
         func newWindow(surface: ghostty_surface_t) {
             let action = "new_window"
             if (!ghostty_surface_binding_action(surface, action, UInt(action.count))) {
@@ -451,6 +458,9 @@ extension Ghostty {
             case GHOSTTY_ACTION_NEW_TAB:
                 newTab(app, target: target)
 
+            case GHOSTTY_ACTION_DUPLICATE_TAB:
+                duplicateTab(app, target: target)
+
             case GHOSTTY_ACTION_NEW_SPLIT:
                 newSplit(app, target: target, direction: action.action.new_split)
 
@@ -752,6 +762,42 @@ extension Ghostty {
             }
         }
 
+        private static func duplicateTab(_ app: ghostty_app_t, target: ghostty_target_s) {
+            switch (target.tag) {
+            case GHOSTTY_TARGET_APP:
+                NotificationCenter.default.post(
+                    name: Notification.ghosttyDuplicateTab,
+                    object: nil,
+                    userInfo: [:]
+                )
+
+            case GHOSTTY_TARGET_SURFACE:
+                guard let surface = target.target.surface else { return }
+                guard let surfaceView = self.surfaceView(from: surface) else { return }
+                guard let appState = self.appState(fromView: surfaceView) else { return }
+                guard appState.config.windowDecorations else {
+                    let alert = NSAlert()
+                    alert.messageText = "Tabs are disabled"
+                    alert.informativeText = "Enable window decorations to use tabs"
+                    alert.addButton(withTitle: "OK")
+                    alert.alertStyle = .warning
+                    _ = alert.runModal()
+                    return
+                }
+
+                NotificationCenter.default.post(
+                    name: Notification.ghosttyDuplicateTab,
+                    object: surfaceView,
+                    userInfo: [
+                        Notification.NewSurfaceConfigKey: SurfaceConfiguration(from: ghostty_surface_inherited_config(surface)),
+                    ]
+                )
+
+            default:
+                assertionFailure()
+            }
+        }
+
         private static func newSplit(
             _ app: ghostty_app_t,
             target: ghostty_target_s,

macos/Sources/Ghostty/Package.swift

@@ -370,6 +370,9 @@ extension Ghostty.Notification {
     /// New tab. Has base surface config requested in userinfo.
     static let ghosttyNewTab = Notification.Name("com.mitchellh.ghostty.newTab")
 
+    /// Duplicate tab. Has base surface config requested in userinfo.
+    static let ghosttyDuplicateTab = Notification.Name("com.mitchellh.ghostty.duplicateTab")
+
     /// New window. Has base surface config requested in userinfo.
     static let ghosttyNewWindow = Notification.Name("com.mitchellh.ghostty.newWindow")
 

src/Surface.zig

@@ -4801,6 +4801,12 @@ pub fn performBindingAction(self: *Surface, action: input.Binding.Action) !bool
             {},
         ),
 
+        .duplicate_tab => return try self.rt_app.performAction(
+            .{ .surface = self },
+            .duplicate_tab,
+            {},
+        ),
+
         .close_tab => |v| return try self.rt_app.performAction(
             .{ .surface = self },
             .close_tab,

src/apprt/action.zig

@@ -83,6 +83,11 @@ pub const Action = union(Key) {
     /// the tab should be opened in a new window.
     new_tab,
 
+    /// Duplicate the current tab. If the target is a surface it should be
+    /// duplicated in the same window as the surface. If the target is the app
+    /// then the tab should be duplicated in a new window.
+    duplicate_tab,
+
     /// Closes the tab belonging to the currently focused split, or all other
     /// tabs, depending on the mode.
     close_tab: CloseTabMode,
@@ -300,6 +305,7 @@ pub const Action = union(Key) {
         quit,
         new_window,
         new_tab,
+        duplicate_tab,
         close_tab,
         new_split,
         close_all_windows,

src/apprt/gtk/class/application.zig

@@ -591,6 +591,8 @@ pub const Application = extern struct {
 
             .new_tab => return Action.newTab(target),
 
+            .duplicate_tab => return Action.duplicateTab(target),
+
             .new_window => try Action.newWindow(
                 self,
                 switch (target) {
@@ -999,6 +1001,7 @@ pub const Application = extern struct {
         self.syncActionAccelerator("win.close", .{ .close_window = {} });
         self.syncActionAccelerator("win.new-window", .{ .new_window = {} });
         self.syncActionAccelerator("win.new-tab", .{ .new_tab = {} });
+        self.syncActionAccelerator("win.duplicate-tab", .{ .duplicate_tab = {} });
         self.syncActionAccelerator("win.close-tab::this", .{ .close_tab = .this });
         self.syncActionAccelerator("tab.close::this", .{ .close_tab = .this });
         self.syncActionAccelerator("win.split-right", .{ .new_split = .right });
@@ -1981,6 +1984,31 @@ const Action = struct {
         }
     }
 
+    pub fn duplicateTab(target: apprt.Target) bool {
+        switch (target) {
+            .app => {
+                log.warn("duplicate tab to app is unexpected", .{});
+                return false;
+            },
+
+            .surface => |core| {
+                // Get the window ancestor of the surface. Surfaces shouldn't
+                // be aware they might be in windows but at the app level we
+                // can do this.
+                const surface = core.rt_surface.surface;
+                const window = ext.getAncestor(
+                    Window,
+                    surface.as(gtk.Widget),
+                ) orelse {
+                    log.warn("surface is not in a window, ignoring duplicate_tab", .{});
+                    return false;
+                };
+                window.duplicateTab(core);
+                return true;
+            },
+        }
+    }
+
     pub fn newWindow(
         self: *Application,
         parent: ?*CoreSurface,

src/apprt/gtk/class/surface.zig

@@ -535,6 +535,7 @@ pub const Surface = extern struct {
     pub fn setParent(
         self: *Self,
         parent: *CoreSurface,
+        force_inherit_pwd: bool,
     ) void {
         const priv = self.private();
 
@@ -558,7 +559,7 @@ pub const Surface = extern struct {
             const config = config_obj.get();
 
             // Setup our pwd if configured to inherit
-            if (config.@"window-inherit-working-directory") {
+            if (config.@"window-inherit-working-directory" or force_inherit_pwd) {
                 if (parent.rt_surface.surface.getPwd()) |pwd| {
                     priv.pwd = glib.ext.dupeZ(u8, pwd);
                     self.as(gobject.Object).notifyByPspec(properties.pwd.impl.param_spec);

src/apprt/gtk/class/tab.zig

@@ -166,9 +166,9 @@ pub const Tab = extern struct {
     /// Set the parent of this tab page. This only affects the first surface
     /// ever created for a tab. If a surface was already created this does
     /// nothing.
-    pub fn setParent(self: *Self, parent: *CoreSurface) void {
+    pub fn setParent(self: *Self, parent: *CoreSurface, force_inherit_pwd: bool) void {
         if (self.getActiveSurface()) |surface| {
-            surface.setParent(parent);
+            surface.setParent(parent, force_inherit_pwd);
         }
     }