Crash: attempt to compare nil with number in clear_items (job.lua:879)

[ILLISIS]

Error

Error while running event level::on_nth_tick(90)
__level__/modules/ctron_plugin/script/job.lua:879: attempt to compare nil with number
stack traceback:
  job.lua:879: in function 'clear_items'
  job.lua:1187: in function '?'
  job.lua:1055: in function 'execute'
  job_processor.lua:26: in function 'process_job_queue'
  control.lua:39: in function 'handler'
  lualib/event_handler.lua:81: in function
  lualib/event_handler.lua:79

Root Cause

In job.lua:879, logistic_network is accessed without a nil check:

local logistic_network = self.station.logistic_network  -- can be nil
if (logistic_network.all_logistic_robots <= 0) then     -- crashes if nil

If the station has no logistic network (e.g. the network was removed or the station is not inside one), self.station.logistic_network returns nil, and the comparison on line 879 throws a non-recoverable error.

Expected Behavior

A nil check on logistic_network before accessing its fields, similar to the existing check on line 882 (if not next(logistic_network.storages)), should guard line 879 as well.

Suggested Fix

local logistic_network = self.station.logistic_network
if not logistic_network then
    debug_lib.VisualDebugText({"ctron_status.no_logi_robots"}, worker, -0.5, 3)
elseif (logistic_network.all_logistic_robots <= 0) then
    debug_lib.VisualDebugText({"ctron_status.no_logi_robots"}, worker, -0.5, 3)
end

[ILLISIS]

Constructron found its way outside the playable boundary to where the station was supposed to be.
It also walked in to the diagonal space where edge transfer will not pick it up.