Segmentation fault when using window decorations (CSD) with GNOME wayland fractional scaling

[vandalt]

Describe the bug
A clear and concise description of what the bug is.

To Reproduce
Steps to reproduce the behavior:

1. Open kitty with hide_window_decorations no (CSD enabled) on GNOME wayland with two monitors with fractional scaling enabled, one with 100% scaling and one with > 100% scaling
2. If kitty is on the 100% scaling, it crashed direct.
3. If kitty starts on the >100% scaling monitor, it crashed when moved to the 100% scaling
4. See error

Environment details

Environment details

kitty 0.36.2 (100f472a08) created by Kovid Goyal
Linux yoga 6.10.10-arch1-1 #1 SMP PREEMPT_DYNAMIC Thu, 12 Sep 2024 17:21:02 +0000 x86_64
Arch Linux 6.10.10-arch1-1 (/dev/tty)

Running under: Wayland (GNOME Shell 47.0) missing: layer_shell
OpenGL: '4.6 (Core Profile) Mesa 24.2.3-arch1.1' Detected version: 4.6
Frozen: False
Fonts:
  medium: JetBrainsMonoNF-Regular: /usr/share/fonts/TTF/JetBrainsMonoNerdFont-Regular.ttf:0
          Features: ()
    bold: JetBrainsMonoNF-SemiBold: /usr/share/fonts/TTF/JetBrainsMonoNerdFont-SemiBold.ttf:0
          Features: ()
  italic: JetBrainsMonoNF-Italic: /usr/share/fonts/TTF/JetBrainsMonoNerdFont-Italic.ttf:0
          Features: ()
      bi: JetBrainsMonoNF-SemiBoldItalic: /usr/share/fonts/TTF/JetBrainsMonoNerdFont-SemiBoldItalic.ttf:0
          Features: ()
Paths:
  kitty: /usr/bin/kitty
  base dir: /usr/lib/kitty
  extensions dir: /usr/lib/kitty/kitty
  system shell: /usr/bin/zsh
Loaded config files:
  /home/vandal/.config/kitty/kitty.conf

Config options different from defaults:
allow_remote_control    yes
disable_ligatures       1
enable_audio_bell       False
font_family             JetBrainsMono Nerd Font
font_size               10.0
listen_on               unix:/tmp/mykitty
mouse_hide_wait         0.0
remember_window_size    False
shell_integration       frozenset({'no-cursor'})
Changed mouse actions:
	ctrl+shift+right press ungrabbed →  combine : mouse_select_command_output : kitty_scrollback_nvim --config ksb_builtin_last_visited_cmd_output
Added shortcuts:
	ctrl+alt+enter →  launch --cwd=current
	kitty_mod+alt+w →  set_window_title
	kitty_mod+m →  new_os_window_with_cwd
Changed shortcuts:
	kitty_mod+g →  kitty_scrollback_nvim --config ksb_builtin_last_cmd_output
	kitty_mod+h →  kitty_scrollback_nvim
Colors:
	active_border_color     #82aaff   
	active_tab_background   #82aaff   
	active_tab_foreground   #1e2030   
	background              #222436   
	color0                  #1b1d2b   
	color1                  #ff757f   
	color10                 #c3e88d   
	color11                 #ffc777   
	color12                 #82aaff   
	color13                 #c099ff   
	color14                 #86e1fc   
	color15                 #c8d3f5   
	color16                 #ff966c   
	color17                 #c53b53   
	color2                  #c3e88d   
	color3                  #ffc777   
	color4                  #82aaff   
	color5                  #c099ff   
	color6                  #86e1fc   
	color7                  #828bb8   
	color8                  #444a73   
	color9                  #ff757f   
	cursor                  #c8d3f5   
	cursor_text_color       #222436   
	foreground              #c8d3f5   
	inactive_border_color   #2f334d   
	inactive_tab_background #2f334d   
	inactive_tab_foreground #545c7e   
	selection_background    #3654a7   
	selection_foreground    #c8d3f5   
	url_color               #4fd6be   

Important environment variables seen by the kitty process:
	PATH                                /home/vandal/.local/bin:/home/vandal/bin:/usr/local/bin:/usr/bin:/usr/local/sbin:/var/lib/flatpak/exports/bin:/opt/fv:/usr/lib/jvm/default/bin:/usr/bin/site_perl:/usr/bin/vendor_perl:/usr/bin/core_perl
	LANG                                en_CA.UTF-8
	EDITOR                              nvim
	SHELL                               /usr/bin/zsh
	DISPLAY                             :0
	WAYLAND_DISPLAY                     wayland-0
	USER                                vandal
	XDG_DATA_DIRS                       /home/vandal/.local/share/flatpak/exports/share:/var/lib/flatpak/exports/share:/usr/local/share/:/usr/share/
	XDG_RUNTIME_DIR                     /run/user/1000
	XDG_CURRENT_DESKTOP                 GNOME
	XDG_MENU_PREFIX                     gnome-
	XDG_SESSION_CLASS                   user
	XDG_SESSION_DESKTOP                 gnome
	XDG_SESSION_TYPE                    wayland

Additional context
I can reproduce the problem with kitty --config NONE, but not when setting hide_window_decorations yes.

I could only test on GNOME wayland. It occurs only with two monitors, one with 100% scaling and one with > 100% scaling with fractional scaling (gsettings set org.gnome.mutter experimental-features "['scale-monitor-framebuffer']"). When both are at 100% scaling or both at >100% scaling, the error does not occur.

kitty --debug-gl Output

[0.048] Compositor missing capabilities: layer_shell
[0.063] Creating window 1 at size: 640x400 and scale 1
[0.063] CSD: old.size: 0x0 new.size: 640x400 needs_update: 1 size_changed: 1 state_changed: 0 buffer_destroyed: 0
[0.063] Created decoration buffers at scale: 1.000000
[0.071] Fractional scale requested: 240/120 = 2.00 for window 1
[0.072] Resizing framebuffer of window: 1 to: 1280x800 window size: 640x400 at scale: 2.000
[0.072] Waiting for swap to commit Wayland surface for window: 1
[0.072] CSD: old.size: 640x400 new.size: 640x400 needs_update: 1 size_changed: 1 state_changed: 0 buffer_destroyed: 0
[0.072] Created decoration buffers at scale: 2.000000
[0.072] Preferred integer buffer scale changed to: 2 for window 1
[0.072] Compositor set top-level bounds of: 1920x1048 for window 1
[0.072] Compositor top-level capabilities: maximize=1 minimize=1 window_menu=1 fullscreen=1
[0.073] XDG top-level configure event for window 1: size: 0x0 states: 
[0.073] XDG surface configure event received and acknowledged for window 1
[0.073] Waiting for swap to commit Wayland surface for window: 1
[0.073] CSD: old.size: 640x400 new.size: 640x400 needs_update: 0 size_changed: 0 state_changed: 0 buffer_destroyed: 0
[0.073] Final window 1 content size: 640x400 resized: 0
[0.073] Setting window 1 "visible area" geometry in configure event: x=0 y=-24 640x424 viewport: 640x400
[0.073] Creating OpenGL context and attaching it to window
[0.093] Window 1 swapped committing surface
[0.117] CSD: old.size: 640x400 new.size: 640x400 needs_update: 0 size_changed: 0 state_changed: 0 buffer_destroyed: 0
[0.120] OS Window created
[0.135] Child launched
[0.135] CSD: old.size: 640x400 new.size: 640x400 needs_update: 0 size_changed: 0 state_changed: 0 buffer_destroyed: 0
[0.137] Compositor set top-level bounds of: 1920x1048 for window 1
[0.137] XDG top-level configure event for window 1: size: 640x424 states: TOPLEVEL_STATE_ACTIVATED 
[0.137] XDG surface configure event received and acknowledged for window 1
[0.137] CSD: old.size: 640x400 new.size: 640x400 needs_update: 1 size_changed: 0 state_changed: 1 buffer_destroyed: 1
[0.140] Created decoration buffers at scale: 2.000000
[0.140] Final window 1 content size: 640x400 resized: 0
[0.140] Setting window 1 "visible area" geometry in configure event: x=0 y=-24 640x424 viewport: 640x400
[0.165] Calling wl_pointer_set_cursor in setCursorImage with surface: 0x64b011540f10 and serial: 0
[0.165] Got notification server capabilities: frozenset({'body', 'body-markup', 'sound', 'icon-static', 'actions', 'persistence'})
[0.252] CSD: old.size: 640x400 new.size: 640x400 needs_update: 1 size_changed: 0 state_changed: 0 buffer_destroyed: 1
[0.253] Created decoration buffers at scale: 2.000000
[1.331] Fractional scale requested: 120/120 = 1.00 for window 1
[1.331] Resizing framebuffer of window: 1 to: 640x400 window size: 640x400 at scale: 1.000
[1.331] Waiting for swap to commit Wayland surface for window: 1
[1.331] CSD: old.size: 640x400 new.size: 640x400 needs_update: 1 size_changed: 1 state_changed: 0 buffer_destroyed: 1

zsh: segmentation fault (core dumped)  kitty --debug-gl

[kovidgoyal]

Post the backtrace from the segfault.