Fix crash on missing dat file

When opening the exporter and missing a dat file, the exporter would crash trying to run rawFile:read on a nil entry
It now also tells you in client if you are missing a dat

Author: LocalIdentity

src/Export/Classes/GGPKData.lua

@@ -127,14 +127,22 @@ end
 
 function GGPKClass:AddDat64Files()
 	local datFiles = self:GetNeededFiles()
+	local missingCount = 0
 	table.sort(datFiles, function(a, b) return a:lower() < b:lower() end)
 	for _, fname in ipairs(datFiles) do
 		local record = { }
 		record.name = fname:match("([^/\\]+)$") .. "c64"
 		local rawFile = io.open(self.oozPath .. fname:gsub("/", "\\") .. "c64", 'rb')
-		record.data = rawFile:read("*all")
-		rawFile:close()
-		t_insert(self.dat, record)
+		if rawFile then
+			record.data = rawFile:read("*all")
+			rawFile:close()
+			t_insert(self.dat, record)
+		else
+			missingCount = missingCount + 1
+		end
+	end
+	if missingCount > 0 then
+		t_insert(main.scriptOutput, { "^7"..string.format("Skipped %d missing cached GGPK data files. Press Ctrl+F5 to refresh GGPK data.", missingCount), height = 14 })
 	end
 end
 

src/Export/Main.lua

@@ -67,6 +67,7 @@ local remainingScripts = { }
 function main:Init()
 	self.inputEvents = { }
 	self.popups = { }
+	self.scriptOutput = { }
 
 	self.datSpecs = LoadModule("spec")
 
@@ -98,7 +99,6 @@ function main:Init()
 			break
 		end
 	end
-	self.scriptOutput = { }
 
 	function print(text)
 		for line in text:gmatch("[^\r\n]+") do