generator.insert no longer throws if slot was empty (never should have); cleaned and patched up refuel.lua a little

src/main/java/li/cil/oc/server/component/UpgradeGenerator.scala

@@ -29,7 +29,7 @@ class UpgradeGenerator(val owner: TileEntity) extends ManagedComponent {
     val count = if (args.count > 0) args.checkInteger(0) else 64
     val player = context.player
     val stack = player.inventory.getStackInSlot(context.selectedSlot)
-    if (stack == null) throw new IllegalArgumentException("selected slot is empty")
+    if (stack == null) return result(Unit, "selected slot is empty")
     if (!TileEntityFurnace.isItemFuel(stack)) {
       return result(Unit, "selected slot does not contain fuel")
     }

src/main/resources/assets/opencomputers/lua/component/generator/bin/refuel.lua

@@ -4,49 +4,54 @@ local component = require("component")
 local robot = require("robot")
 local shell = require("shell")
 
-local args = shell.parse(...)
+-- Not using shell.parse to allow `refuel 1 -10`, the -10 would be
+-- parsed as an option otherwise.
+local args = {...}
 
 local function printUsage()
   print("Usages:")
-  print("'refuel' to get the current fuel count")
+  print("refuel")
-  print("'refuel <slot> [amount]' to refuel [amount] from that specific slot,\n  or try to completely fill it")
+  print("  Gets the current fuel count.")
-  print("'refuel all' to refuel from all slots")
+  print("refuel <slot> [amount]")
+  print("  Refuel the specified number of items (default")
+  print("  as many as possible) from the specified slot.")
+  print("refuel all")
+  print("  Refuel from all slots.")
 end
 
 if component.isAvailable("generator") then
   local g = component.generator
   if #args == 0 then
-    print("Current Number of items in generator: "..g.count())
+    print("Current number of items in generator: "..g.count())
   elseif tonumber(args[1]) ~= nil then
-    print("Refuelling from slot"..args[1].."...")
+    local slot = tonumber(args[1])
-    robot.select(tonumber(args[1]))
+    local count = tonumber(args[2]) or 64
-    local success, msg
+    robot.select(slot)
-    if tonumber(args[2]) ~= nil then
+    if count > 0 then
-      if tonumber(args[2]) > 0 then
+      io.write("Refueling from slot "..slot.."... ")
-        success, msg = g.insert(tonumber(args[2]))
+      local success, msg = g.insert(count)
-      elseif tonumber(args[2]) < 0 then
-        success = g.remove(math.abs(tonumber(args[2])))
-        if not (success == true) then msg = "Could not remove item, generator is empty" end
-      else
-        msg = "You can't insert 0 of an item!"
-      end
-    else
-      success, msg = g.insert()
-    end
       if success then
-      print("Success.")
+        print("success.")
       else
-      print("Error: "..msg)
+        print("failed: "..msg)
       end
+    elseif count < 0 then
+      io.write("Ejecting into slot "..slot.."... ")
+      if g.remove(-count) then
+        print("success.")
+      else
+        print("failed.")
+      end
+    end -- else: ignore zero
     robot.select(1)
   elseif string.lower(args[1]) == "all" then
-    io.write("Refuelling from all slots...")
+    io.write("Refueling from all slots... ")
     for i = 1, 16 do
       robot.select(i)
       g.insert()
     end
     robot.select(1)
-    print("Done.")
+    print("done.")
   else
     printUsage()
   end