fix: Allow empty window name in tmuxp (#444)

#445 will address and additional issue where formats of empty
strings are potentially being filtered out as if they held no value.

In re: tmux-python/tmuxp#822

CHANGES

@@ -12,6 +12,10 @@ $ pip install --user --upgrade --pre libtmux
 
 - _Insert changes/features/fixes for next release here_
 
+### Bug fixes
+
+- `Session.new_window()`: Improve support for `window_name: ''` downstream in tmuxp (#444, credit: @trankchung)
+
 ## libtmux 0.15.7 (2022-09-23)
 
 - Move `.coveragerc` -> `pyproject.toml` (#443)

src/libtmux/session.py

@@ -250,8 +250,8 @@ def new_window(
         window_args += (
             '-F"%s"' % formats.FORMAT_SEPARATOR.join(tmux_formats),
         )  # output
-        if window_name:
-            window_args += ("-n%s" % window_name,)
+        if window_name is not None and isinstance(window_name, str):
+            window_args += ("-n", window_name)
 
         window_args += (
             # empty string for window_index will use the first one available

tests/test_window.py

@@ -5,7 +5,7 @@
 import pytest
 
 from libtmux import exc
-from libtmux.common import has_gte_version
+from libtmux.common import has_gte_version, has_lt_version
 from libtmux.pane import Pane
 from libtmux.server import Server
 from libtmux.session import Session
@@ -290,3 +290,23 @@ def test_select_layout_accepts_no_arg(server: Server, session: Session) -> None:
 
     window = session.new_window(window_name="test_window")
     window.select_layout()
+
+
+@pytest.mark.skipif(
+    has_lt_version("3.2"), reason="needs filter introduced in tmux >= 3.2"
+)
+def test_empty_window_name(session: Session) -> None:
+    session.set_option("automatic-rename", "off")
+    window = session.new_window(window_name="''", attach=True)
+
+    assert window == session.attached_window
+    assert window.get("window_name") == "''"
+
+    cmd = session.cmd(
+        "list-windows",
+        "-F",
+        "#{window_name}",
+        "-f",
+        "#{==:#{session_name}," + session.name + "}",
+    )
+    assert "''" in cmd.stdout