Non-PUA symbol is rendered too big if followed by space

[mkrieger1]

I suppose this might be similar to #3501 or #1903, however, this time the problem is that a symbol is rendered too big. It's also not generally rendered too big, but only (this is the pattern I found) if it is followed by a space or "nothing".

To demonstrate, in Ghostty started with --config-default-files=false, running bash, execute:

+$ printf "\u2714\n"
✔
+$ printf "\u2714'\n"
✔'
+$ printf "'\u2714'\n"
'✔'
+$ printf "'\u2714 '\n"
'✔ '

The first time and last time, the checkmark is way too big:

Notice also how in the last example the total width is correct (i.e, the second ' is still in the 4th column), but the 3rd column is occupied by the right half of the checkmark instead of a space.

Here is how the same is rendered in the preview of this post in my browser, which looks like I expect:

Ghostty version info

Ghostty 1.0.2-main+29c2f095

Version
  - version: 1.0.2-main+29c2f095
  - channel: tip
Build Config
  - Zig version: 0.13.0
  - build mode : builtin.OptimizeMode.ReleaseFast
  - app runtime: apprt.Runtime.gtk
  - font engine: font.main.Backend.fontconfig_freetype
  - renderer   : renderer.OpenGL
  - libxev     : main.Backend.io_uring
  - desktop env: gnome
  - GTK version:
    build      : 4.8.3
    runtime    : 4.8.3
  - libadwaita : enabled
    build      : 1.2.2
    runtime    : 1.2.2
  - libX11     : enabled
  - libwayland : enabled

[mitchellh]

This is done on purpose, search "PUA" and you'll find a lot of discussion on the reasoning.

[mkrieger1]

I think I understand the reasoning now (mainly from #1071), but to clarify: Is it that the checkmark is normally big and Ghostty scales it down if it is not followed by a space, or is it normally small and Ghostty scales it up if it is followed by a space?

Am I correct to believe that the checkmark should be small?

[mitchellh]

That's a good question. Let me look at U+2714 Unicode properties and make sure.

[mkrieger1]

I received a notification that this was closed as a duplicate. I can't see anywhere, a duplicate of what? I would like to follow this.

[pluiedev]

It's like what Mitchell says — there's already loads of issues and discussions about this (keyword: PUA/Private Use Area), e.g. #4029, #1110

[mkrieger1]

I understand, however, U+2714 is not in any PUA (U+E000…U+F8FF, U+F0000…U+FFFFD, U+100000…U+10FFFD).

[pluiedev]

Hm. This discussion may be mislabelled then. Sorry about that!