WowAce

Attempting to roll over an icon on the World Map raises the following error:

Message: Interface\AddOns\GatherMate2\Display.lua:114: attempt to index local 'tooltip' (a nil value)
Time: Tue Mar 12 19:23:37 2019
Count: 18
Stack: Interface\AddOns\GatherMate2\Display.lua:114: attempt to index local 'tooltip' (a nil value)
[C]: ?
Interface\AddOns\GatherMate2\Display.lua:114: in function <Interface\AddOns\GatherMate2\Display.lua:99>
(tail call): ?

This is because WorldMapTooltip has been deprecated and merged into GameTooltip. So, the fix is to use GameTooltip going forward.

Same goes for the reference to WorldMapTooltip in the hidePin function.

Can confirm.  Removing the selection for world map vs GameTooltip removes the error and allows it continue without error.

local function showPin(self)
	if (self.title) then
		local tooltip, pinset


		tooltip = GameTooltip
		pinset = minimapPins
		local x, y = self:GetCenter()
		local parentX, parentY = UIParent:GetCenter()
		if ( x > parentX ) then
			tooltip:SetOwner(self, "ANCHOR_LEFT")
		else
			tooltip:SetOwner(self, "ANCHOR_RIGHT")
		end

		local t = db.trackColors
		local text = format(tooltip_template, t[self.nodeType].Alpha*255, t[self.nodeType].Red*255, t[self.nodeType].Green*255, t[self.nodeType].Blue*255, self.title)
		for id, pin in pairs(pinset) do
			if pin:IsMouseOver() and pin.title and pin ~= self then
				text = text .. "\n" .. format(tooltip_template, t[pin.nodeType].Alpha*255, t[pin.nodeType].Red*255, t[pin.nodeType].Green*255, t[pin.nodeType].Blue*255, pin.title)
			end
		end
		tooltip:SetText(text)
		tooltip:Show()
	end
end

local function hidePin(self)
		GameTooltip:Hide()
end