Variation selector U+FE0F rendered as a space

[neurocyte]

Describe the bug
Kitty renders the follow code point sequence as a no entry sign followed by a space:

U+26D4 NO ENTRY character (⛔)
U+FE0F VARIATION SELECTOR-16 character (️)

This takes three columns in kitty. Every other terminal renders this in two columns.

To Reproduce

printf '\xe2\x9b\x94\xef\xb8\x8f'

Environment details

kitty 0.37.0 (abe411ce40) created by Kovid Goyal
Linux dent 6.12.1-arch1-1 #1 SMP PREEMPT_DYNAMIC Fri, 22 Nov 2024 16:04:27 +0000 x86_64
S{PRETTY_NAME} 6.12.1-arch1-1 (/dev/tty)

DISTRIB_ID="Arch"
DISTRIB_RELEASE="rolling"
DISTRIB_DESCRIPTION="Arch Linux"
Running under: Wayland (niri 0.1.10-1 (unknown commit)) missing: single_pixel_buffer
OpenGL: '3.1.0 NVIDIA 565.57.01' Detected version: 3.1
Frozen: False
Fonts:
  medium: NotoSansMono-Regular: /usr/share/fonts/noto/NotoSansMono-Regular.ttf:0
          Features: ()
    bold: NotoSansMono-Bold: /usr/share/fonts/noto/NotoSansMono-Bold.ttf:0
          Features: ()
  italic: NotoSansMono-Regular: /usr/share/fonts/noto/NotoSansMono-Regular.ttf:0
          Features: ()
      bi: NotoSansMono-Bold: /usr/share/fonts/noto/NotoSansMono-Bold.ttf:0
          Features: ()
Paths:
  kitty: /home/cjv/pkgs/kitty/kitty/launcher/kitty
  base dir: /home/cjv/pkgs/kitty
  extensions dir: /home/cjv/pkgs/kitty/kitty
  system shell: /usr/bin/fishenv
System color scheme: dark. Applied color theme type: none

Config options different from defaults:

Important environment variables seen by the kitty process:
	PATH                                /home/cjv/pkgs/kitty/kitty/launcher:/home/cjv/.local/share/bob/nvim-bin:/home/cjv/pkgs/zls/zig-out/bin:/home/cjv/.dotnet/tools:/home/cjv/.nimble/bin:/home/cjv/go:/home/cjv/.ghcup/bin:/home/cjv/src/flow/zig-out/bin:/home/cjv/.cargo/bin:/home/cjv/.local/bin:/home/cjv/.cabal/bin:/home/cjv/.local/lib/node_modules/.bin:/home/cjv/.nix-profile/bin:/nix/var/nix/profiles/default/bin:/home/cjv/pkgs/kitty/kitty/launcher:/home/cjv/.local/share/bob/nvim-bin:/home/cjv/pkgs/zls/zig-out/bin:/home/cjv/.dotnet/tools:/home/cjv/.nimble/bin:/home/cjv/go:/home/cjv/.ghcup/bin:/home/cjv/src/flow/zig-out/bin:/home/cjv/.cargo/bin:/home/cjv/.local/bin:/home/cjv/.cabal/bin:/home/cjv/.local/lib/node_modules/.bin:/home/cjv/.nix-profile/bin:/nix/var/nix/profiles/default/bin:/usr/local/bin:/usr/bin:/usr/local/sbin:/opt/cuda/bin:/opt/cuda/nsight_compute:/opt/cuda/nsight_systems/bin:/var/lib/flatpak/exports/bin:/usr/lib/jvm/default/bin:/usr/bin/site_perl:/usr/bin/vendor_perl:/usr/bin/core_perl:/usr/lib/rustup/bin:/usr/local/bin:/home/cjv/.dapr/bin:/usr/local/bin:/home/cjv/.dapr/bin
	LANG                                en_DK.UTF-8
	EDITOR                              edit
	SHELL                               /usr/bin/fishenv
	WAYLAND_DISPLAY                     wayland-1
	USER                                cjv
	XCURSOR_SIZE                        24
	XDG_SEAT                            seat0
	XDG_SESSION_ID                      3
	XDG_VTNR                            2
	XDG_SESSION_CLASS                   user
	XDG_DATA_DIRS                       /home/cjv/.local/share/flatpak/exports/share:/var/lib/flatpak/exports/share:/usr/local/share/:/usr/share/:/home/cjv/.nix-profile/share:/nix/var/nix/profiles/default/share:/home/cjv/.nix-profile/share:/nix/var/nix/profiles/default/share
	XDG_RUNTIME_DIR                     /run/user/1000
	XDG_CURRENT_DESKTOP                 niri
	XDG_SESSION_TYPE                    wayland
	XDG_SESSION_DESKTOP                 niri

Additional context
I also tried kitty --config NONE and switching to en_US.UTF-8, but this did not make a difference.

[neurocyte]

I guess this may be related to 3810?

[neurocyte]

For some background - this is an issue for me in flow because these code points are returned in diagnostic messages from an LSP and I do not define them myself. I could sanitize them from the messages, but that would be a kitty specific workaround (my very first!) because they display correctly everywhere else.

[trygveaa]

This looks like a regression introduced in commit cabd6c0 (found with a bisect). It renders correctly in the latest release (0.37.0).

I guess this may be related to 3810?

No, not really. There's no ZWJ characters in your string.

[neurocyte]

It renders correctly in the latest release (0.37.0).

Yes, you are correct, it's a regression. It renders fine in 0.37.0.

I've just double checked the latest master commit too, and it still has this issue.

I also checked the cell branch, and it does not have this issue. But it's a bit unstable so I'll stick to master.