GF Check for same character set in all styles (especially Roman vs Italic)

[davelab6]

Observed behaviour

As we expand families without italics to have them, it is important that the character set be equal between them, so that text set in the Roman, when switched to Italic, doesn't then render in a fallback family.

Expected behaviour

Add a simple check that compares the characters in each file, and if the total is not equal for all, list the characters missing from each file that has less than the file with the max.

Resources and exact process needed to replicate

This could also be a sibling check.

[chrissimpkins]

There are examples where this is appropriate. Eg, Cyrillic with Macedonian and Serbian localization support will have italics only localized forms that make char counts/glyph names differ between roman/italic builds.

[punchcutter]

Small caps can also differ between upright and italic so the char count won't necessarily match there.

[davelab6]

Localized support and small caps are a difference in glyphs set but not character set?