Apostrophe fixes for 2015 theme

[peterwilsoncc]

https://core.trac.wordpress.org/ticket/59693

Apostrophe fixes for 2015 theme, including font files.

@karmatosed @sabernhardt I'm a little confused about which files from the zip are meant to be included, could you please clarify?

For now I've included the files from the Google Fonts zip but the file sizes are roughly double for each of the files which seems a lot.

[github-actions]

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[sabernhardt]

• Google Fonts uses the variable font, and Fontsource did/does not, so that could easily explain the larger file size.
• If we replace only the WOFF2 format, all of the woff?ver=23 updates would need to return to woff?ver=21. (The ticket has WOFF files, though I do not know their source.)

[peterwilsoncc]

Thank you. For this ticket I think it's better to use the non-variable fonts to keep the fix as simple as possible.

In the future, if there is a switch to variable fonts in older themes, they can be wrapped in @supports queries to allow for fallbacks.

I've pushed up the files in the Fontsouce zip on the ticket -- the files are now substantially smaller so it would be good to test they contain the expected glyphs

[sabernhardt]

The font stylesheet identifies 385 Unicode values for the Latin subset, and the newer Fontsource WOFF2 files are quite different. You could copy the tables I used to check them, but switch to the code editor view before pasting the HTML.

Already with Twenty Fifteen 3.7, Firefox told me it used Times New Roman instead of Noto Serif for 63 of the 112 glyphs within the U+2000-206F range. The newer Fontsource files in the patch also fall back for three more glyphs:

• 2191 Upwards Arrow
• 2193 Downwards Arrow
• 2215 Division Slash

Nine glyphs significantly changed the amount of space between them and other characters (including the U+02BC apostrophe) since the previous font version:

• 0060 Grave Accent
• 00A8 Diaeresis
• 00B4 Acute Accent
• 00B8 Cedilla
• 02BB Modifier Letter Turned Comma
• 02BC Modifier Letter Apostrophe
• 02C6 Modifier Letter Circumflex Accent
• 02DA Ring Above
• 02DC Small Tilde

separation with version 21:

separation with version 23:

Additionally, the newer font has noticeably thicker line glyphs such as dashes, and the uppercase letters are shorter now. For comparison, I made images of 83 glyphs with some considerable changes from version 21 to version 23.