Merge pull request #4119 from myk002/myk_autochop

[autochop] better error output on malformed command

docs/changelog.txt

@@ -62,6 +62,7 @@ Template for new versions:
 - `misery`: fix error when changing the misery factor
 
 ## Misc Improvements
+- `autochop`: better error output when target burrows are not specified on the commandline
 - wherever units are listed in DFHack tools, properties like "agitated" or (-trained-) are now shown
 - `work-now`: now saves its enabled status with the fort
 

library/lua/argparse.lua

@@ -130,7 +130,7 @@ end
 
 function stringList(arg, arg_name, list_length)
     if not list_length then list_length = 0 end
-    local list = arg:split(',')
+    local list = arg and (arg):split(',') or {}
     if list_length > 0 and #list ~= list_length then
         arg_error(arg_name,
                   'expected %d elements; found %d', list_length, #list)

plugins/lua/autochop.lua

@@ -32,7 +32,11 @@ function setTargets(max, min)
 end
 
 local function do_set_burrow_config(var_name, val, burrows)
-    for _,bspec in ipairs(argparse.stringList(burrows)) do
+    burrows = argparse.stringList(burrows)
+    if #burrows == 0 then
+        qerror('no target burrows specified')
+    end
+    for _,bspec in ipairs(burrows) do
         local config = autochop_getBurrowConfig(bspec)
         config[var_name] = val
         autochop_setBurrowConfig(config.id, config.chop, config.clearcut,