Bugzilla

(In reply to Kagami Rosylight [:saschanaz] (they/them) from comment #46)
> Somehow the `overrides` pref we are talking about is changing as this thread goes on... per comment #20 I tested with `-AllTargets,+FontVisibilityLangPack` but per comment #43 it's `+AllTargets,-FontVisibilityBaseSystem`?

Yeah hahaha, it is because of +/-AllTargets. FontVisibilityBaseSystem and FontVisibilityLangPack are used as a level of protection. Having +AllTargets in overrides enables both FontVisibilityBaseSystem and FontVisibilityLangPack, and FontVisibilityBaseSystem takes precedence over FontVisibilityLangPack. So, if you have +AllTargets, you have to disable FontVisibilityBaseSystem to set the protection level to FontVisibilityLangPack, but if you have -AllTargets, then both FontVisibilityBaseSystem and FontVisibilityLangPack gets disabled. Then we put +FontVisibilityLangPack to set the protection level to FontVisibilityLangPack.

(In reply to Fatih Kilic from comment #39)
> I think the issue is the way the font protection level is set. When you enable AllTargets, the FontVisibilityBaseSystem RFPTarget becomes active too, and [here](https://searchfox.org/mozilla-central/source/layout/base/nsPresContext.cpp#768) we return the font level as BaseSystem, hence not allowing the fonts in LangPack list. If you want to use fonts in LangPack (which is only `One UI Sans KR VF` for Android), then you would have to set your overrides as +AllTargets,-FontVisibilityBaseSystem. What this would essentially do is, set the level to LangPack by skipping BaseSystem check.

(In reply to Kagami Rosylight [:saschanaz] (they/them) from comment #46)
> Somehow the `overrides` pref we are talking about is changing as this thread goes on... per comment #20 I tested with `-AllTargets,+FontVisibilityLangPack` but per comment #43 it's `+AllTargets,-FontVisibilityBaseSystem`?

Yeah hahaha, it is because of +/-AllTargets. FontVisibilityBaseSystem and FontVisibilityLangPack are used as a level of protection. Having +AllTargets in overrides enables both FontVisibilityBaseSystem and FontVisibilityLangPack, and FontVisibilityBaseSystem takes precedence over FontVisibilityLangPack. So, if you have +AllTargets, you have to disable FontVisibilityBaseSystem to set the protection level to FontVisibilityLangPack, but if you have -AllTargets, then both FontVisibilityBaseSystem and FontVisibilityLangPack gets disabled. Then we put +FontVisibilityLangPack to set the protection level to FontVisibilityLangPack. 

Both achieve the same thing for font protection, but `-AllTargets,+FontVisibilityLangPack` is more isolated/specific because it only enables a single protection while `+AllTargets,-FontVisibilityBaseSystem` enables all protections available but sets the fontvisibility level to langpack.

(In reply to Fatih Kilic from comment #39)
> I think the issue is the way the font protection level is set. When you enable AllTargets, the FontVisibilityBaseSystem RFPTarget becomes active too, and [here](https://searchfox.org/mozilla-central/source/layout/base/nsPresContext.cpp#768) we return the font level as BaseSystem, hence not allowing the fonts in LangPack list. If you want to use fonts in LangPack (which is only `One UI Sans KR VF` for Android), then you would have to set your overrides as +AllTargets,-FontVisibilityBaseSystem. What this would essentially do is, set the level to LangPack by skipping BaseSystem check.

(In reply to Kagami Rosylight [:saschanaz] (they/them) from comment #46)
> Somehow the `overrides` pref we are talking about is changing as this thread goes on... per comment #20 I tested with `-AllTargets,+FontVisibilityLangPack` but per comment #43 it's `+AllTargets,-FontVisibilityBaseSystem`?

Yeah hahaha, it is because of +/-`AllTargets`. (I'm omitting FontVisibility part for better readability) `BaseSystem` and `LangPack` are used as a level of protection. Having `+AllTargets` in overrides enables both `BaseSystem` and `LangPack`, and `BaseSystem` takes precedence over `LangPack`. So, if you have `+AllTargets`, you have to disable `BaseSystem` to set the protection level to `LangPack`, but if you have `-AllTargets`, then both `BaseSystem` and `LangPack` gets disabled. Then we put `+LangPack` to set the protection level to `LangPack`. 

Both achieve the same thing for font protection, but `-AllTargets,+FontVisibilityLangPack` is more isolated/specific because it only enables a single protection while `+AllTargets,-FontVisibilityBaseSystem` enables all protections available but sets the fontvisibility level to langpack.

(In reply to Fatih Kilic from comment #39)
> I think the issue is the way the font protection level is set. When you enable AllTargets, the FontVisibilityBaseSystem RFPTarget becomes active too, and [here](https://searchfox.org/mozilla-central/source/layout/base/nsPresContext.cpp#768) we return the font level as BaseSystem, hence not allowing the fonts in LangPack list. If you want to use fonts in LangPack (which is only `One UI Sans KR VF` for Android), then you would have to set your overrides as +AllTargets,-FontVisibilityBaseSystem. What this would essentially do is, set the level to LangPack by skipping BaseSystem check.