When shell is set to . respect the SHELL environment variable in the environment in which kitty is launched

Fixes #7714

docs/changelog.rst

@@ -134,6 +134,8 @@ Detailed list of changes
 
 - Wayland GNOME: Fix a small rendering artifact when docking a window at a screen edge or maximizing it (:iss:`7701`)
 
+- When :opt:`shell` is set to ``.`` respect the SHELL environment variable in the environment in which kitty is launched (:pull:`7714`)
+
 
 0.35.2 [2024-06-22]
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

docs/glossary.rst

@@ -98,6 +98,11 @@ Variables that influence kitty behavior
 
    Same as :envvar:`VISUAL`. Used if :envvar:`VISUAL` is not set.
 
+.. envvar:: SHELL
+
+   Specifies the default shell kitty will run when :opt:`shell` is set to
+   :code:`.`.
+
 .. envvar:: GLFW_IM_MODULE
 
    Set this to ``ibus`` to enable support for IME under X11.

kitty/constants.py

@@ -180,7 +180,7 @@ def wakeup_io_loop() -> None:
 shell_integration_dir = os.path.join(kitty_base_dir, 'shell-integration')
 fonts_dir = os.path.join(kitty_base_dir, 'fonts')
 try:
-    shell_path = pwd.getpwuid(os.geteuid()).pw_shell or '/bin/sh'
+    shell_path = os.environ.get('SHELL') or pwd.getpwuid(os.geteuid()).pw_shell or '/bin/sh'
 except KeyError:
     with suppress(Exception):
         print('Failed to read login shell via getpwuid() for current user, falling back to /bin/sh', file=sys.stderr)

kitty/options/definition.py

@@ -2909,6 +2909,7 @@
 opt('shell', '.',
     long_text='''
 The shell program to execute. The default value of :code:`.` means to use
+the value of of the :envvar:`SHELL` environment variable or if unset,
 whatever shell is set as the default shell for the current user. Note that on
 macOS if you change this, you might need to add :code:`--login` and
 :code:`--interactive` to ensure that the shell starts in interactive mode and