Save split window targetting for later

Author: tony

tmuxp/window.py

@@ -328,7 +328,7 @@ def split_window(self, target=None, attach=True):
         if target:
             tmux_args += ('-t%s' % target,)
         else:
-            tmux_args += ('-t%s' % self.panes[-1].get('pane_index'),)
+            tmux_args += ('-t%s' % self.panes[0].get('pane_id'),)
 
         tmux_args += (
             '-P', '-F%s' % ''.join(tmux_formats)     # output