Merriweather Sans: inconsistent OS/2 achVendID between upright and italic variable fonts

[stream-enterer]

Summary

The upright and italic variable font files for Merriweather Sans have inconsistent OS/2.achVendID values, causing Qt/KDE to split the family into two separate entries.

Details

• Upright (MerriweatherSans-VariableFont_wght.ttf): achVendID = "STC\x00" (null-padded)
• Italic (MerriweatherSans-Italic-VariableFont_wght.ttf): achVendID = "STC " (space-padded)

Qt uses the vendor ID to disambiguate font families. Because the padding differs, Qt treats them as two separate families:

• Merriweather Sans [STC] — only upright styles (Regular, Bold, Light, ExtraBold)
• Merriweather Sans [STC ] — only italic styles (Italic, Bold Italic, Light Italic, ExtraBold Italic)

This means in KDE System Settings (and any Qt-based font picker), users cannot select both upright and italic variants of Merriweather Sans as a single family.

fontconfig handles this fine — the issue is specifically in how Qt's QFontDatabase interprets the vendor ID.

Fix

Set achVendID to the same value in both files. Null-padding ("STC\x00") is the conventional approach per the OpenType spec.

Reproduction

from fontTools.ttLib import TTFont

upright = TTFont("MerriweatherSans-VariableFont_wght.ttf")
italic = TTFont("MerriweatherSans-Italic-VariableFont_wght.ttf")

print(repr(upright["OS/2"].achVendID))  # 'STC\x00'
print(repr(italic["OS/2"].achVendID))   # 'STC '

Environment

• Font source: https://github.com/SorkinType/Merriweather-Sans (issues disabled there)
• Qt 6.10.2, KDE Plasma on Linux
• Fonts downloaded from Google Fonts

[emmamarichal]

@m4rc1e could you have a look?