https://bugzilla.redhat.com/show_bug.cgi?id=1531986
--- Comment #3 from Cheng-Chia Tseng pswo10680@gmail.com --- Since the rules in the fontconfig file of AR PL UMing package try to prepend itself in the generic Sans-serif and Monospace font candidate list besides Serif one, installing the package will definitely affect the default Chinese font behavior.
There three main thoughts on this issue: 1. UMing is a 明體/宋體 typeface which is grossly referred to the generic Serif font family. It must not claim itself as a candidate font to prepend to the generic "Sans-serif" or "Monospace" font family or it creates unexpected result for everyone who install the package.
The rules to claim AR PL UMing as a generic sans-serif or monospace font family should be removed
2. AR PL UMing provides AR PL UMing CN variant for China, although the glyph in TW, HK and CN are all the same. The project planned to support different variants of the glyph in different regions but failed to do so after the initial commit. The project latter stopped and is not maintained anymore.
However, we can still map AR PL UMing CN to map zh-cn language tag for the users to let applications using fontconfig technology can see AR PL UMing as a generic Serif font family.
3. As we are using Source Han Serif font as the default Chinese font candidate in the generic Serif font family, we should make sure that installing AR PL UMing package won't change the default Chinese font behavior.
In my f27 installation with traditional Chinese environment, I installed AR PL UMing package as well, and the output of fc-match -s Serif still see Source Han Serif TW font as the first Chinese candidate, so the Chinese font candidate list seems to work as expected.
$ fc-match -s Serif SourceHanSerifTW-Regular.otf: "思源宋體 TW" "Regular" DejaVuSerif.ttf: "DejaVu Serif" "Book" DejaVuSerif-Bold.ttf: "DejaVu Serif" "Bold" DejaVuSerif-Italic.ttf: "DejaVu Serif" "Italic" DejaVuSerif-BoldItalic.ttf: "DejaVu Serif" "Bold Italic" NimbusRoman-Regular.t1: "Nimbus Roman" "Regular" StandardSymbolsPS.t1: "Standard Symbols PS" "Regular" STIX-Regular.otf: "STIX" "Regular" STIX-Bold.otf: "STIX" "Bold" STIX-Italic.otf: "STIX" "Italic" STIX-BoldItalic.otf: "STIX" "Bold Italic" Caladea-Regular.ttf: "Caladea" "Regular" SourceHanSerifCN-Regular.otf: "思源宋体 CN" "Regular" Symbola.ttf: "Symbola" "Regular" mingliu.ttc: "新細明體" "Regular" Lohit-Bengali.ttf: "Lohit Bengali" "Regular" Lohit-Gujarati.ttf: "Lohit Gujarati" "Regular" Lohit-Tamil.ttf: "Lohit Tamil" "Regular" Meera.ttf: "Meera" "Regular" Lohit-Kannada.ttf: "Lohit Kannada" "Regular" Lohit-Telugu.ttf: "Lohit Telugu" "Regular" uming.ttc: "AR PL UMing TW" "Light"
In all, the rules of the fontconfig file provided by cjk-uming-fonts package should be modified to remove the "sans-serif" and "monospace" part. It would be better to add "AR PL UMing CN" for "zh-cn" language to let programs see it as a Serif font in zh-cn environment as well.