In GDI, Hanguls in font with a stub cmap4 are missing.

[CyanoHao]

It occurs in TTC, Mono/Term/Fixed Slab SC/TC/HC, any subfamily.

sarasa-regular.ttc v0.12.5, Windows 10.0.19041, Korean:

[CyanoHao]

Some test results:

otfccdump sarasa-gothic-cl-regular.ttf | otfccbuild --stub-cmap4 -O3 -o sarasa-nocmap4.ttf → Hanguls are missing. (sarasa-gothic-cl-regular.ttf is extracted from sarasa-gothic-ttf-0.12.5.7z.)

otfccdump SourceHanSansK-Regular.otf | otfccbuild --stub-cmap4 -O3 -o shs-nocmap4.otf → Good. (v2.001)

otfccdump SourceHanSansK-Regular.otf | otfcc-c2q | otfccbuild --stub-cmap4 -O3 -o shs-nocmap4.ttf → Good. (v2.001)

otfccdump shs-nocmap4.ttf --pretty -o shs.json, and then edit OS/2.ulCodePageRange1:

"ulCodePageRange1": {
    "latin1": true,
    "latin2": true,
    "cyrillic": true,
    "vietnamese": true,
    "jis": false,
    "gbk": false,
    "korean": true,
    "koreanJohab": false,
    "macRoman": true,
    "oem": true
},

and build with otfccbuild shs.json --stub-cmap4 -O3 -o cp949.ttf. → The icon is broken. (The font looks good in Windows Font Viewer.)

[be5invis]

Fixed in Dev by upgrading the dependency.