macos_option_as_alt is not honored when CAPS_LOCK is ON

[vkz]

Describe the bug
kitty.conf has macos_option_as_alt left to ensure Opt+b et al behave like Alt+b et al on Mac OS. And they do work as expected unless CAPS_LOCK is on. In which case they behave as if the setting is macos_option_as_alt no i.e. you get diacritics as output.

To confirm I'm not expecting anything out of the ordinary here, I tried in iTerm 2 and it behaved as I would've expected, so I'm guessing it is a bug with how kitty handles CAPS_LOCK mod.

To Reproduce
Steps to reproduce the behavior:

1. macos_option_as_alt left on OSX in your kitty.conf
2. try Opt+b or Opt+f and confirm they move cursor by word back and forth
3. toggle CAPS_LOCK to ON
4. try Opt+b or Opt+f and see diacritic chars printed out to terminal

To confirm that is indeed what's happening here's the output of kitty --debug-keyboard that captures both cases with CAPS_LOCK on and off and the output does appear to confirm the claim above. Compare and contrast:

kitty --debug-keyboard without CAPS_LOCK

-------------- flags changed -----------------
NSEvent: type=FlagsChanged loc=(451.203,684.398) time=1017786.9 flags=0x80120 win=0x121294cc0 winNum=322576 ctxt=0x0 keyCode=58
flagsChanged: modifier: alt native_key: 0x3a (<noname>) glfw_key: 0xe063 mods: alt 
[132.663] on_key_input: glfw key: 0xe063 native_code: 0x3a action: PRESS mods: alt text: '' state: 0 ignoring as keyboard mode does not support encoding this event
---------------- key down -------------------
NSEvent: type=KeyDown loc=(451.203,684.398) time=1017798.0 flags=0x80120 win=0x121294cc0 winNum=322576 ctxt=0x0 chars="b" unmodchars="b" repeat=0 keyCode=45
Press: native_key: 0x2d (b) glfw_key: 0x62 mods: alt char_count: 1 deadKeyState: 0 repeat: 0 text: <none> glfw_key: b marked_text: ()
[143.780] on_key_input: glfw key: 0x62 native_code: 0x2d action: PRESS mods: alt text: '' state: 0 sent encoded key to child: ^[ b 

kitty --debug-keybeard with CAPS_LOCK

-------------- flags changed -----------------
NSEvent: type=FlagsChanged loc=(40.0938,881.328) time=1018389.5 flags=0x10100 win=0x140f67fc0 winNum=322703 ctxt=0x0 keyCode=57
flagsChanged: modifier: capslock native_key: 0x39 (<noname>) glfw_key: 0xe00e mods: capslock 
[16.808] on_key_input: glfw key: 0xe00e native_code: 0x39 action: PRESS mods: capslock text: '' state: 0 ignoring as keyboard mode does not support encoding this event
-------------- flags changed -----------------
NSEvent: type=FlagsChanged loc=(40.0938,881.328) time=1018393.3 flags=0x90120 win=0x140f67fc0 winNum=322703 ctxt=0x0 keyCode=58
flagsChanged: modifier: alt native_key: 0x3a (<noname>) glfw_key: 0xe063 mods: alt+capslock 
[20.674] on_key_input: glfw key: 0xe063 native_code: 0x3a action: PRESS mods: alt+capslock text: '' state: 0 ignoring as keyboard mode does not support encoding this event
---------------- key down -------------------
NSEvent: type=KeyDown loc=(40.0938,881.328) time=1018393.3 flags=0x90120 win=0x140f67fc0 winNum=322703 ctxt=0x0 chars="ı" unmodchars="b" repeat=0 keyCode=45
Press: native_key: 0x2d (b) glfw_key: 0x62 mods: alt+capslock char_count: 1 deadKeyState: 0 repeat: 0 
	insertText: ı replacementRange: (9223372036854775807, 0)
text: 0xc4 0xb1 glfw_key: b marked_text: ()
[20.704] on_key_input: glfw key: 0x62 native_code: 0x2d action: PRESS mods: alt+capslock text: 'ı' state: 0 sent key as text to child:  ı

Environment details

kitty 0.34.1 (7f61f1f9f3) created by Kovid Goyal
Darwin  23.6.0 Darwin Kernel Version 23.6.0: Mon Jul 29 21:14:46 PDT 2024; root:xnu-10063.141.2~1/RELEASE_ARM64_T6031 arm64
ProductName:		macOS ProductVersion:		14.6.1 BuildVersion:		23G93
Frozen: True
Paths:
  kitty: /Applications/kitty.app/Contents/MacOS/kitty
  base dir: /Applications/kitty.app/Contents/Resources/kitty
  extensions dir: /Applications/kitty.app/Contents/Resources/Python/lib/kitty-extensions
  system shell: /bin/zsh
Loaded config files:
  /Users/user/.config/kitty/kitty.conf

Config options different from defaults:
bold_font            Source Code Pro Medium
bold_italic_font     Source Code Pro Medium Italic
clipboard_max_size   0
enable_audio_bell    False
font_family          Source Code Pro Light
font_size            12.0
italic_font          Source Code Pro Light Italic
macos_option_as_alt  2
tab_title_template   {fmt.bold}{sup.index}{fmt.nobold}{fmt.fg.red}{bell_symbol}{activity_symbol}{fmt.fg.tab}{title}
visual_bell_duration 0.1
Added shortcuts:
	ctrl+m →  send_key ctrl+@
Removed shortcuts:
	cmd+, →  edit_config_file
	cmd+enter →  new_window
	cmd+h →  hide_macos_app
	cmd+k →  clear_terminal to_cursor active
	cmd+m →  minimize_macos_window
	cmd+n →  new_os_window
	cmd+q →  quit
	cmd+t →  new_tab
	cmd+w →  close_tab
	ctrl+cmd+, →  load_config_file
	ctrl+cmd+f →  toggle_fullscreen
	opt+cmd+h →  hide_macos_other_apps
	opt+cmd+r →  clear_terminal reset active
	opt+cmd+s →  toggle_macos_secure_keyboard_entry
	shift+cmd+/ →  open_url https://sw.kovidgoyal.net/kitty/
	shift+cmd+[ →  previous_tab
	shift+cmd+] →  next_tab
	shift+cmd+d →  close_window
	shift+cmd+w →  close_os_window
Changed shortcuts:
	kitty_mod+1 →  goto_tab 1
	kitty_mod+2 →  goto_tab 2
	kitty_mod+3 →  goto_tab 3
	kitty_mod+4 →  goto_tab 4
	kitty_mod+5 →  goto_tab 5
	kitty_mod+6 →  goto_tab 6
	kitty_mod+7 →  goto_tab 7
	kitty_mod+8 →  goto_tab 8
	kitty_mod+9 →  goto_tab 9

Important environment variables seen by the kitty process:
	PATH                                /Applications/kitty.app/Contents/MacOS:/usr/bin:/bin:/usr/sbin:/sbin
	LANG                                en_GB.UTF-8
	SHELL                               /bin/zsh
	USER                                user

Additional context
Try to reproduce the problem with kitty --config NONE if you cannot then post a minimal kitty.conf that reproduces the problem. If the problem involves interaction with some other terminal program post a minimal config for that program to reproduce the problem as well.