What you are seeing is indeed a problem of the way text is rendered in Plasma. Some text (for example in the taskbar) is first rendered to an image to apply shadow and halo effects on it. Since with an image you do not know where it is displayed, and Qt cannot apply sub pixel hinting to text.
This bug, however, is about a completely unrelated issue. The first application(s) that uses text (usually the Plasma Workspace or KWin) completely ignores font related settings from .fonts.conf file, such as anti aliasing settings or font sizes. As the title says, it is therefor even possible that those applications _have_ sub pixel hinting enabled, while it is disabled in System Settings. I still think it is an upstream bug, see comment #10.
Re comment #19 and comment #20:
What you are seeing is indeed a problem of the way text is rendered in Plasma. Some text (for example in the taskbar) is first rendered to an image to apply shadow and halo effects on it. Since with an image you do not know where it is displayed, and Qt cannot apply sub pixel hinting to text.
This bug, however, is about a completely unrelated issue. The first application(s) that uses text (usually the Plasma Workspace or KWin) completely ignores font related settings from .fonts.conf file, such as anti aliasing settings or font sizes. As the title says, it is therefor even possible that those applications _have_ sub pixel hinting enabled, while it is disabled in System Settings. I still think it is an upstream bug, see comment #10.