Fix error when optional --ignore is not specified

Author: JanSharp

changelog.txt

@@ -1,5 +1,7 @@
 ---------------------------------------------------------------------------------------------------
 Version: 0.1.5
+  Bugfixes:
+    - Fix error when the optional '--ignore' argument was not specified
 ---------------------------------------------------------------------------------------------------
 Version: 0.1.4
 Date: 2023-02-10

src/main.lua

@@ -267,8 +267,10 @@ if output_dir ~= source_dir then
   ignore_path_lut[output_dir:str()] = true
 end
 
-for _, ignore_path in ipairs(args.ignore_paths) do
-  ignore_path_lut[ignore_path:to_fully_qualified(source_dir):normalize():str()] = true
+if args.ignore_paths then
+  for _, ignore_path in ipairs(args.ignore_paths) do
+    ignore_path_lut[ignore_path:to_fully_qualified(source_dir):normalize():str()] = true
+  end
 end
 
 local function warn_for_unhandled_entry(mode, entry_path)