`U+0332 COMBINING LOW LINE` renders too far upward.

[RokeJulianLockhart]

Defect Report

Title

As aforestated:

The U+0332 COMBINING LOW LINE renders too far upward.

Font

Full file name, for example NotoSansArmenian-Regular.ttf.

You can upload the problem font here unless it is a Chinese, Japanese or Korean font (these are large).

google-noto-sans-mono-fonts

Where the font came from, and when

/usr/share/fonts/google-noto/NotoSansMono-Regular.ttf, from google-noto-sans-mono-fonts-20240701-2.fc41.noarch, at +2025-04-07T15:56:09+00:00:

1. #!/usr/bin/env pwsh
   #Requires -PSEdition Core
   #Requires -Version 7.5.0
   $FontName = rpm -qa google-noto-sans-mono-fonts
   dnf --refresh repoquery -l $FontName | grep -E 'Regular'

2. - /etc/fonts/conf.d/57-google-noto-sans-mono.conf
   - /usr/share/fontconfig/conf.avail/57-google-noto-sans-mono.conf
   - /usr/share/fonts/google-noto
   - /usr/share/fonts/google-noto/NotoSansMono-Black.ttf
   - /usr/share/fonts/google-noto/NotoSansMono-Bold.ttf
   - /usr/share/fonts/google-noto/NotoSansMono-Condensed.ttf
   - /usr/share/fonts/google-noto/NotoSansMono-CondensedBlack.ttf
   - /usr/share/fonts/google-noto/NotoSansMono-CondensedBold.ttf
   - /usr/share/fonts/google-noto/NotoSansMono-CondensedExtraBold.ttf
   - /usr/share/fonts/google-noto/NotoSansMono-CondensedExtraLight.ttf
   - /usr/share/fonts/google-noto/NotoSansMono-CondensedLight.ttf
   - /usr/share/fonts/google-noto/NotoSansMono-CondensedMedium.ttf
   - /usr/share/fonts/google-noto/NotoSansMono-CondensedSemiBold.ttf
   - /usr/share/fonts/google-noto/NotoSansMono-CondensedThin.ttf
   - /usr/share/fonts/google-noto/NotoSansMono-ExtraBold.ttf
   - /usr/share/fonts/google-noto/NotoSansMono-ExtraCondensed.ttf
   - /usr/share/fonts/google-noto/NotoSansMono-ExtraCondensedBlack.ttf
   - /usr/share/fonts/google-noto/NotoSansMono-ExtraCondensedBold.ttf
   - /usr/share/fonts/google-noto/NotoSansMono-ExtraCondensedExtraBold.ttf
   - /usr/share/fonts/google-noto/NotoSansMono-ExtraCondensedExtraLight.ttf
   - /usr/share/fonts/google-noto/NotoSansMono-ExtraCondensedLight.ttf
   - /usr/share/fonts/google-noto/NotoSansMono-ExtraCondensedMedium.ttf
   - /usr/share/fonts/google-noto/NotoSansMono-ExtraCondensedSemiBold.ttf
   - /usr/share/fonts/google-noto/NotoSansMono-ExtraCondensedThin.ttf
   - /usr/share/fonts/google-noto/NotoSansMono-ExtraLight.ttf
   - /usr/share/fonts/google-noto/NotoSansMono-Light.ttf
   - /usr/share/fonts/google-noto/NotoSansMono-Medium.ttf
   + /usr/share/fonts/google-noto/NotoSansMono-Regular.ttf
   - /usr/share/fonts/google-noto/NotoSansMono-SemiBold.ttf
   - /usr/share/fonts/google-noto/NotoSansMono-SemiCondensed.ttf
   - /usr/share/fonts/google-noto/NotoSansMono-SemiCondensedBlack.ttf
   - /usr/share/fonts/google-noto/NotoSansMono-SemiCondensedBold.ttf
   - /usr/share/fonts/google-noto/NotoSansMono-SemiCondensedExtraBold.ttf
   - /usr/share/fonts/google-noto/NotoSansMono-SemiCondensedExtraLight.ttf
   - /usr/share/fonts/google-noto/NotoSansMono-SemiCondensedLight.ttf
   - /usr/share/fonts/google-noto/NotoSansMono-SemiCondensedMedium.ttf
   - /usr/share/fonts/google-noto/NotoSansMono-SemiCondensedSemiBold.ttf
   - /usr/share/fonts/google-noto/NotoSansMono-SemiCondensedThin.ttf
   - /usr/share/fonts/google-noto/NotoSansMono-Thin.ttf
   - /usr/share/metainfo/org.fedoraproject.google-noto-sans-mono-fonts.metainfo.xml

Font Version

1. #!/usr/bin/env sh
   dnf info --refresh google-noto-sans-mono-fonts

2. Installed packages
   Name            : google-noto-sans-mono-fonts
   Epoch           : 0
   Version         : 20240701
   Release         : 2.fc41
   Architecture    : noarch
   Installed size  : 20.5 MiB
   Source          : google-noto-fonts-20240701-2.fc41.src.rpm
   From repository : anaconda
   Vendor          : Fedora Project

OS name and version

This is especially important if the font came pre-installed.

It did.

1. #!/usr/bin/env pwsh
   #Requires -PSEdition Core
   #Requires -Version 7.5.0
   (Get-Content -LiteralPath '/etc/os-release' | ConvertFrom-StringData | Select-Object 'CPE_NAME').CPE_NAME

2. CPE_NAME="cpe:/o:fedoraproject:fedora:41"

Application name and version

If the issue is observed using a specific app.

I've confirmed this in firefox-137.0-2.fc41.x86_64.

Issue

Summarize the issue briefly -- one paragraph preferred:

1. Steps to reproduce
2. Observed results
3. Expected results
4. Additional information

Unicode chart, technical specs, shaping info, comparison with non-Noto fonts, comparison with earlier version of the same font (regression cases).

In order to use 2 characters inside a <th>, I utilised a combination of N, º, ¹ and ◌̲ in the stead of №. ² <u> was unsuitable for this, because it rendered at the typographic baseline. Unfortunately, although ◌̲ appeared to consider the actual placement of the character, the typeface misplaces it at ⪅ 13 px on a 2560 × 1440 px grid.

Character data

Please include real character data to illustrate your issue -- Unicode codepoints are helpful. This makes it possible for developers who don't know the language or script to copy/paste the text to reproduce the issue.

- Codepoint: U+00BA
  Symbol: º
- Codepoint: U+0332
  Symbol:  ̲
    # [^SUCSH3]

³

Screenshot

⁴

Footnotes

1. en.wikipedia.org/w/index.php?title=Numero_sign&oldid=1273237443#cite_ref-3 ↩

2. #issue-2512382473 ↩

3. stackoverflow.com/revisions/38135244/1 ↩

4. reddit.com/r/Unicode/comments/16lusdq/comment/mfltef5 ↩

[moyogo]

The U+0332 COMBINING LOW LINE renders too far upward

Can you provide an actual screenshot and an image or description of what you think would be better?

was unsuitable for this, because it rendered at the typographic baseline. Unfortunately, although ◌̲ appeared to consider the actual placement of the character, the typeface misplaces it at ⪅ 13 px on a 2560 × 1440 px grid.

Trying to emulate № U+2116 this way is likely bound to have issues. It’s not clear what you mean in any case.

[RokeJulianLockhart]

Can you provide an actual screenshot and an image or description of what you think would be better?

@moyogo, currently, there is no padding between the combining line and the (superscript-esque) character, giving the character the appearance of a "Ω", albeit with a filled base. Instead, I believe that it should have at least 1 px between them.

If I compare it to variable-with Roboto (on Fenix for AOSP), although the combining line inexplicably renders above the character, it does at least render with some space between it and the character it combines with:

Does that explain?

[moyogo]

Does that explain?

No, not at all. But it seems we get different results.

Here’s what I get for Nº̲ (004E, 00BA, 0332).

I’d strongly recommend not using this hack. U+0332 may be positioned under the normal baseline or just below the superscript letter, depending on the preference. Both positioning are attested. Noto is doing it reasonably. There is nothing to fix, this would just be another preference.

[RokeJulianLockhart]

But it seems we get different results.

@moyogo, my last example was lazy; I should have waited until I was at my PC. However, I also believe you might have missed part of my report. Specifically, you're looking at it at too great of a scale. If I zoom in, I see the same:

However, that isn't so at ⪅ 13 px on a 2560 × 1440 px at 100% scale (as aforementioned):

I would presume that there should always be at least 1 px of space, because for it to go from separate to combined with the character seems nonsensical to me.

[moyogo]

Thank you for the screenshot. It’s clear what you want.

Look at ª with pixels touching at sizes ⪅ 13 px, there are not enough pixels and the grays help identifying the shapes. This is no different. At those sizes, even normal sized letters have their pixels next to pixels of detached diacritics.

If Noto were manually hinted with emphasis on small sizes, this may be a valid problem, but that’s not the targeted use.

[RokeJulianLockhart]

@moyogo, thanks. Do you know what kind of size this font is designed for? I ask because 10 pt (which this appears to reproduce at 100% zoom at, on my 1440 px monitor) is the default font size for my desktop environment, and appears very similar to whatever Segoe UI is set to on Windows 11.