fix(split): Passthrough target correctly

Author: tony

src/libtmux/pane.py

@@ -491,6 +491,7 @@ def select_pane(self) -> "Pane":
     def split(
         self,
         /,
+        target: t.Optional[t.Union[int, str]] = None,
         start_directory: t.Optional[str] = None,
         attach: bool = False,
         direction: t.Optional[PaneDirection] = None,
@@ -504,6 +505,8 @@ def split(
 
         Parameters
         ----------
+        target : optional
+            Optional, custom *target-pane*, used by :meth:`Window.split`.
         attach : bool, optional
             make new window the current window after creating it, default
             True.
@@ -617,6 +620,9 @@ def split(
         if not attach:
             tmux_args += ("-d",)
 
+        if target is not None:
+            tmux_args += (f"-t{target}",)
+
         if environment:
             if has_gte_version("3.0"):
                 for k, v in environment.items():
@@ -807,6 +813,7 @@ def at_right(self) -> bool:
     #
     def split_window(
         self,
+        target: t.Optional[t.Union[int, str]] = None,
         attach: bool = False,
         start_directory: t.Optional[str] = None,
         vertical: bool = True,
@@ -844,6 +851,7 @@ def split_window(
         if size is None and percent is not None:
             size = f'{str(percent).rstrip("%")}%'
         return self.split(
+            target=target,
             attach=attach,
             start_directory=start_directory,
             direction=PaneDirection.Below if vertical else PaneDirection.Right,

src/libtmux/window.py

@@ -239,6 +239,7 @@ def split(
         """
         active_pane = self.active_pane or self.panes[0]
         return active_pane.split(
+            target=target,
             start_directory=start_directory,
             attach=attach,
             direction=direction,