Fix attempt to index field 'target' (a nil value)

Author: Quezler

mods/se-interstellar-construction-requests-fulfillment/info.json

@@ -2,7 +2,7 @@
     "name": "se-interstellar-construction-requests-fulfillment",
     "title": "Space Exploration - interstellar construction requests fulfillment",
     "description": "Keeping building equipment stocked at every planet is tedious, just shoot it there from nauvis.",
-    "version": "1.0.2",
+    "version": "1.0.3",
     "author": "Quezler",
     "factorio_version": "1.1",
     "dependencies": [

mods/se-interstellar-construction-requests-fulfillment/scripts/handler.lua

@@ -98,6 +98,7 @@ function Handler.shoot(struct)
 end
 
 function Handler.handle_construction_alert(alert)
+  if not alert.target then return end -- attempt to index field 'target' (a nil value)
   if not alert.target.valid then return end -- ghost might have been removed or revived already
   if alert.target.name ~= "entity-ghost" then return end -- can be "item-request-proxy" or "tile-ghost"