add select_layout with no args

Author: tony

libtmux/window.py

@@ -115,15 +115,21 @@ def select_layout(self, layout=None):
         custom: custom dimensions (see :term:`tmux(1)` manpages).
 
         :param layout: string of the layout, 'even-horizontal', 'tiled', etc.
+           Entering None (leaving this blank) is same as ``select-layout``
+           with no layout. In recent tmux versions, it picks the most recently
+           set layout.
         :type layout: str
 
         """
-
-        proc = self.cmd(
+        cmd = [
             'select-layout',
-            '-t%s:%s' % (self.get('session_id'), self.index),
-            layout
-        )
+            '-t%s:%s' % (self.get('session_id'), self.index)
+        ]
+
+        if layout:  # tmux allows select-layout without args
+            cmd.append(layout)
+
+        proc = self.cmd(*cmd)
 
         if proc.stderr:
             raise exc.LibTmuxException(proc.stderr)

tests/test_window.py

@@ -251,3 +251,10 @@ def test_move_window_to_other_session(server, session):
     new_session = server.new_session("test_move_window")
     window.move_window(session=new_session.get('session_id'))
     assert new_session.get_by_id(window.get("window_id")) == window
+
+
+def test_select_layout_accepts_no_arg(server, session):
+    """tmux allows select-layout with no arguments, so let's allow it here."""
+
+    window = session.new_window(window_name='test_window')
+    window.select_layout()