Battleground Context

[CaptainBlagbird]

Can someone explain the battleground query context to me better? This is what I found out so far:

Corresponding campaigns:

Player in AvA Zone (Home)
	BGQUERY_UNKNOWN:            -
	BGQUERY_LOCAL:              Home
	BGQUERY_ASSIGNED_CAMPAIGN:  Home
	BGQUERY_ASSIGNED_AND_LOCAL: Home
	GetCurrentCampaignId():     Home
	
Player in AvA Zone (Guest)
	BGQUERY_UNKNOWN:            -
	BGQUERY_LOCAL:              Guest
	BGQUERY_ASSIGNED_CAMPAIGN:  Guest
	BGQUERY_ASSIGNED_AND_LOCAL: Guest
	GetCurrentCampaignId():     Guest
	
Player in PvE Zone (Map displaying Home)
	BGQUERY_UNKNOWN:            -
	BGQUERY_LOCAL:              -
	BGQUERY_ASSIGNED_CAMPAIGN:  Home
	BGQUERY_ASSIGNED_AND_LOCAL: -
	GetCurrentCampaignId():     -
	
Player in PvE Zone (All keeps white on map)
	BGQUERY_UNKNOWN:            -
	BGQUERY_LOCAL:              -
	BGQUERY_ASSIGNED_CAMPAIGN:  -
	BGQUERY_ASSIGNED_AND_LOCAL: -
	GetCurrentCampaignId():     -
	
Player in PvE Zone (Map displaying no keeps because no home/guest campaign set yet)
	BGQUERY_UNKNOWN:            -
	BGQUERY_LOCAL:              -
	BGQUERY_ASSIGNED_CAMPAIGN:  -
	BGQUERY_ASSIGNED_AND_LOCAL: -
	GetCurrentCampaignId():     -

(Tested with GetKeepAlliance(keepId, bgContext) in API 100013; keepId being a keep that belongs to a different alliance in home/guest campaign, bgContext being the listed BattlegroundQueryContextType number)

So I have 2 (actually 3) concrete questions:

1. What is BGQUERY_ASSIGNED_AND_LOCAL? It doesn't seem to be different from BGQUERY_LOCAL
2. When does the map display white keeps (instead of the home campaign), and how can I detect it in lua?

With question 2 I'd like to complete this function:

-- Get the battleground context that matches the displayed AvA map
local function GetDisplayedBattlegroundContext()
    local bgQuery = BGQUERY_UNKNOWN
    if IsPlayerInAvAWorld() then
        bgQuery = BGQUERY_LOCAL
    elseif false then  -- TODO: Is map displaying white keeps
        bgQuery = BGQUERY_UNKNOWN
    elseif GetAssignedCampaignId() ~= NONE then
        bgQuery = BGQUERY_ASSIGNED_CAMPAIGN
    end
    return bgQuery
end