Prevent populating the checklist with empty data

kconfig_hardened_check/engine.py

@@ -254,6 +254,8 @@ def populate_simple_opt_with_data(opt, data, data_type):
            f'invalid opt type "{opt.type}"'
     assert(data_type in SIMPLE_OPTION_TYPES), \
            f'invalid data type "{data_type}"'
+    assert(data), \
+           f'empty data'
 
     if data_type != opt.type:
         return

kconfig_hardened_check/test_engine.py

@@ -53,8 +53,11 @@ class TestEngine(unittest.TestCase):
                    parsed_kconfig_options, parsed_cmdline_options, kernel_version,
                    result):
         # populate the checklist with data
+        if parsed_kconfig_options:
             populate_with_data(checklist, parsed_kconfig_options, 'kconfig')
+        if parsed_cmdline_options:
             populate_with_data(checklist, parsed_cmdline_options, 'cmdline')
+        if kernel_version:
             populate_with_data(checklist, kernel_version, 'version')
 
         # now everything is ready, perform the checks