Add combine_profname() to combine profile name parts into joint name

... and add some tests for it.

utils/test/test-common.py

@@ -11,8 +11,9 @@
 
 import unittest
 from common_test import AATest, setup_all_loops
+from apparmor.common import AppArmorBug
 
-from apparmor.common import type_is_str, split_name
+from apparmor.common import type_is_str, split_name, combine_profname
 
 class TestIs_str_type(AATest):
     tests = [
@@ -37,6 +38,23 @@ class AaTest_split_name(AATest):
     def _run_test(self, params, expected):
         self.assertEqual(split_name(params), expected)
 
+class AaTest_combine_profname(AATest):
+    tests = [
+        # name parts                        expected full profile name
+        (['foo'],                           'foo'),
+        (['foo', 'bar'],                    'foo//bar'),
+        (['foo', 'bar', 'baz'],             'foo//bar//baz'),
+        (['foo', 'bar', None],              'foo//bar'),
+        (['foo', 'bar', 'baz', None],       'foo//bar//baz'),
+    ]
+
+    def _run_test(self, params, expected):
+        self.assertEqual(combine_profname(params), expected)
+
+    def test_wrong_type(self):
+        with self.assertRaises(AppArmorBug):
+            combine_profname('foo')
+
 
 setup_all_loops(__name__)
 if __name__ == '__main__':