Fixing hang in get_module_qualname_from_path

This commit fixes a possible hang in the get_module_qualname...
function.  When running against a '.' target, the while statement
would loop forever looking for a head of '/', when all it would
ever find was '.'.  Now either option is enough to break the loop.

A head of '.' already indicates we're as far down as we can get
since there is no non-file path left.

Closes-Bug: #1538633
Change-Id: I4aca741b816e4203d6b4da4e62c5edd37d553da4

bandit/core/utils.py

@@ -186,7 +186,7 @@ def get_module_qualname_from_path(path):
                                 ' Missing path or file name' % (path))
 
     qname = [os.path.splitext(tail)[0]]
-    while head != '/':
+    while head not in ['/', '.']:
         if os.path.isfile(os.path.join(head, '__init__.py')):
             (head, tail) = os.path.split(head)
             qname.insert(0, tail)

tests/unit/core/test_util.py

@@ -103,6 +103,14 @@ class UtilTests(testtools.TestCase):
             self.tempdir, 'good', 'a', 'b', 'c', 'test_typical.py'))
         self.assertEqual('good.a.b.c.test_typical', name)
 
+    def test_get_module_qualname_from_path_with_dot(self):
+        '''Test get_module_qualname_from_path with a "." .'''
+
+        name = b_utils.get_module_qualname_from_path(os.path.join(
+            '.', '__init__.py'))
+
+        self.assertEqual('__init__', name)
+
     def test_get_module_qualname_from_path_abs_missingmid(self):
         # Test get_module_qualname_from_path with missing module
         # __init__.py