[siweia]

I just came up with an idea, the code below does fix the override buttons update as well. (for rActionbar)
Not sure whether it taints or not.

local updater = CreateFrame("Frame")
updater:RegisterEvent("UPDATE_VEHICLE_ACTIONBAR")
updater:SetScript("OnEvent", function()
    for i = 1, 12 do
        local button = _G["ActionButton"..i]
        local texture = GetActionTexture(button.action)
        if texture then
            button.icon:SetTexture(texture)
            button.icon:Show()
        else
            button.icon:Hide()
        end
    end
end)