Taint in certain conditions

[p3lim]

1x [ADDON_ACTION_BLOCKED] AddOn 'WorldFlightMap' tried to call the protected function 'Frame:SetPassThroughButtons()'.
[string "@!BugGrabber/BugGrabber.lua"]:480: in function <!BugGrabber/BugGrabber.lua:480>
[string "=[C]"]: in function `SetPassThroughButtons'
[string "@Blizzard_MapCanvas/Blizzard_MapCanvas.lua"]:189: in function `AcquirePin'
[string "@Blizzard_SharedMapDataProviders/WorldQuestDataProvider.lua"]:320: in function `AddWorldQuest'
[string "@Blizzard_SharedMapDataProviders/WorldQuestDataProvider.lua"]:246: in function `RefreshAllData'
[string "@Blizzard_SharedMapDataProviders/WorldQuestDataProvider.lua"]:179: in function `OnEvent'
[string "@Blizzard_MapCanvas/MapCanvas_DataProviderBase.lua"]:99: in function `SignalEvent'
[string "@Blizzard_MapCanvas/Blizzard_MapCanvas.lua"]:106: in function <...aceBlizzard_MapCanvas/Blizzard_MapCanvas.lua:105>
[string "=[C]"]: in function `secureexecuterange'
[string "@Blizzard_MapCanvas/Blizzard_MapCanvas.lua"]:109: in function `OnEvent'
[string "@Blizzard_FlightMap/Blizzard_FlightMap.lua"]:116: in function <...aceBlizzard_FlightMap/Blizzard_FlightMap.lua:111>

Locals:
_ = Frame {
 RegisterEvent = <function> defined @!BugGrabber/BugGrabber.lua:486
 0 = <userdata>
 UnregisterEvent = <function> defined @!BugGrabber/BugGrabber.lua:486
 SetScript = <function> defined @!BugGrabber/BugGrabber.lua:486
}
event = "ADDON_ACTION_BLOCKED"
events = <table> {
 ADDON_ACTION_BLOCKED = <function> defined @!BugGrabber/BugGrabber.lua:552
 ADDON_ACTION_FORBIDDEN = <function> defined @!BugGrabber/BugGrabber.lua:552
 PLAYER_LOGIN = <function> defined @!BugGrabber/BugGrabber.lua:546
 LUA_WARNING = <function> defined @!BugGrabber/BugGrabber.lua:561
 ADDON_LOADED = <function> defined @!BugGrabber/BugGrabber.lua:506
}

"upstream" issue: Stanzilla/WoWUIBugs#453