Sessions: Fix os_window_size and os_window_class not applying to the first OS Window

Fixes #4957

docs/changelog.rst

@@ -39,6 +39,9 @@ Detailed list of changes
 
 - Remote control: Allow using :ref:`Boolean operators <search_syntax>` when constructing queries to match windows or tabs
 
+- Sessions: Fix :code:`os_window_size` and :code:`os_window_class` not applying to the first OS Window (:iss:`4957`)
+
+
 0.25.0 [2022-04-11]
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 

docs/overview.rst

@@ -149,7 +149,7 @@ For example:
 
     # Create a new OS window
     new_os_window
-    # set new window size to 80x25 cells
+    # set new window size to 80x25 cells (if specifed before new_os_window will apply to first OS window)
     os_window_size 80c 25c
     # set the --class for the new OS window
     os_window_class mywindow

kitty/boss.py

@@ -11,8 +11,8 @@ from functools import partial
 from gettext import gettext as _
 from time import monotonic
 from typing import (
-    Any, Callable, Container, Dict, Iterable, Iterator, List, Optional,
-    Sequence, Set, Tuple, Union
+    Any, Callable, Container, Dict, Iterable, Iterator, List, Optional, Set,
+    Tuple, Union
 )
 from weakref import WeakValueDictionary
 
@@ -274,7 +274,7 @@ class Boss:
         for sc in self.global_shortcuts.values():
             self.keymap.pop(sc, None)
 
-    def startup_first_child(self, os_window_id: Optional[int], startup_sessions: Sequence[Optional[Session]] = ()) -> None:
+    def startup_first_child(self, os_window_id: Optional[int], startup_sessions: Iterable[Session] = ()) -> None:
         si = startup_sessions or create_sessions(get_options(), self.args, default_session=get_options().startup_session)
         for startup_session in si:
             self.add_os_window(startup_session, os_window_id=os_window_id)
@@ -723,7 +723,7 @@ class Boss:
     def toggle_macos_secure_keyboard_entry(self) -> None:
         toggle_secure_input()
 
-    def start(self, first_os_window_id: int) -> None:
+    def start(self, first_os_window_id: int, startup_sessions: Iterable[Session]) -> None:
         if not getattr(self, 'io_thread_started', False):
             self.child_monitor.start()
             self.io_thread_started = True
@@ -734,7 +734,7 @@ class Boss:
                 self.startup_first_child(first_os_window_id, startup_sessions=tuple(sess))
                 self.launch_urls(*urls)
             else:
-                self.startup_first_child(first_os_window_id)
+                self.startup_first_child(first_os_window_id, startup_sessions=startup_sessions)
 
         if get_options().update_check_interval > 0 and not self.update_check_started and getattr(sys, 'frozen', False):
             from .update_check import run_update_check

kitty/main.py

@@ -29,7 +29,7 @@ from .fonts.render import set_font_family
 from .options.types import Options
 from .options.utils import DELETE_ENV_VAR
 from .os_window_size import initial_window_size_func
-from .session import get_os_window_sizing_data
+from .session import create_sessions, get_os_window_sizing_data
 from .types import SingleKey
 from .utils import (
     cleanup_ssh_control_masters, detach, expandvars, log_error,
@@ -168,14 +168,16 @@ def _run_app(opts: Options, args: CLIOptions, bad_lines: Sequence[BadLine] = ())
     if not is_wayland() and not is_macos:  # no window icons on wayland
         set_x11_window_icon()
     with cached_values_for(run_app.cached_values_name) as cached_values:
+        startup_sessions = tuple(create_sessions(opts, args, default_session=opts.startup_session))
+        wincls = (startup_sessions[0].os_window_class if startup_sessions else '') or args.cls or appname
         with startup_notification_handler(extra_callback=run_app.first_window_callback) as pre_show_callback:
             window_id = create_os_window(
-                    run_app.initial_window_size_func(get_os_window_sizing_data(opts), cached_values),
+                    run_app.initial_window_size_func(get_os_window_sizing_data(opts, startup_sessions[0] if startup_sessions else None), cached_values),
                     pre_show_callback,
                     args.title or appname, args.name or args.cls or appname,
-                    args.cls or appname, load_all_shaders, disallow_override_title=bool(args.title))
+                    wincls, load_all_shaders, disallow_override_title=bool(args.title))
         boss = Boss(opts, args, cached_values, global_shortcuts)
-        boss.start(window_id)
+        boss.start(window_id, startup_sessions)
         if bad_lines:
             boss.show_bad_config_lines(bad_lines)
         try:

kitty/session.py

@@ -3,18 +3,17 @@
 
 import shlex
 import sys
-from typing import Generator, List, Optional, Union, TYPE_CHECKING
+from typing import TYPE_CHECKING, Generator, Iterator, List, Optional, Union
 
 from .cli_stub import CLIOptions
-from .options.utils import to_layout_names, window_size
 from .constants import kitty_exe
 from .layout.interface import all_layouts
 from .options.types import Options
+from .options.utils import to_layout_names, window_size
 from .os_window_size import WindowSize, WindowSizeData, WindowSizes
 from .typing import SpecialWindowInstance
 from .utils import log_error, resolved_shell
 
-
 if TYPE_CHECKING:
     from .window import CwdRequest
 
@@ -153,7 +152,7 @@ def create_sessions(
     cwd_from: Optional['CwdRequest'] = None,
     respect_cwd: bool = False,
     default_session: Optional[str] = None
-) -> Generator[Session, None, None]:
+) -> Iterator[Session]:
     if args and args.session:
         if isinstance(args.session, PreReadSession):
             session_data = '' + str(args.session)