Do not crash when running AST checks and the document contains null bytes

Author: florentx

CHANGES.txt

@@ -17,6 +17,9 @@ Changelog
 
 * Correctly report other E12 errors when E123 is ignored. (Issue #103)
 
+* Do not crash when running AST checks and the document contains null bytes.
+  (Issue #184)
+
 
 1.4.5 (2013-03-06)
 ------------------

pep8.py

@@ -1205,9 +1205,12 @@ def __init__(self, filename=None, lines=None,
 
     def report_invalid_syntax(self):
         exc_type, exc = sys.exc_info()[:2]
-        offset = exc.args[1]
-        if len(offset) > 2:
-            offset = offset[1:3]
+        if len(exc.args) > 1:
+            offset = exc.args[1]
+            if len(offset) > 2:
+                offset = offset[1:3]
+        else:
+            offset = (1, 0)
         self.report_error(offset[0], offset[1] or 0,
                           'E901 %s: %s' % (exc_type.__name__, exc.args[0]),
                           self.report_invalid_syntax)
@@ -1324,7 +1327,7 @@ def check_logical(self):
     def check_ast(self):
         try:
             tree = compile(''.join(self.lines), '', 'exec', PyCF_ONLY_AST)
-        except SyntaxError:
+        except (SyntaxError, TypeError):
             return self.report_invalid_syntax()
         for name, cls, _ in self._ast_checks:
             checker = cls(tree, self.filename)

testsuite/test_api.py

@@ -10,6 +10,15 @@
 E11 = os.path.join(ROOT_DIR, 'testsuite', 'E11.py')
 
 
+class DummyChecker(object):
+    def __init__(self, tree, filename):
+        pass
+
+    def run(self):
+        if False:
+            yield
+
+
 class APITestCase(unittest.TestCase):
     """Test the public methods."""
 
@@ -68,13 +77,6 @@ def check_dummy(logical_line, tokens):
                             for name, func, args in options.logical_checks))
 
     def test_register_ast_check(self):
-        class DummyChecker(object):
-            def __init__(self, tree, filename):
-                pass
-
-            def run(self):
-                if False:
-                    yield
         pep8.register_check(DummyChecker, ['Z701'])
 
         self.assertTrue(DummyChecker in pep8._checks['tree'])
@@ -87,18 +89,14 @@ def run(self):
                             for name, cls, args in options.ast_checks))
 
     def test_register_invalid_check(self):
-        class DummyChecker(object):
+        class InvalidChecker(DummyChecker):
             def __init__(self, filename):
                 pass
 
-            def run(self):
-                if False:
-                    yield
-
         def check_dummy(logical, tokens):
             if False:
                 yield
-        pep8.register_check(DummyChecker, ['Z741'])
+        pep8.register_check(InvalidChecker, ['Z741'])
         pep8.register_check(check_dummy, ['Z441'])
 
         for checkers in pep8._checks.values():
@@ -306,3 +304,13 @@ def test_styleguide_check_files(self):
         self.assertRaises(Exception, pep8style.check_files, [42])
         # TODO: runner
         # TODO: input_file
+
+    def test_check_nullbytes(self):
+        pep8.register_check(DummyChecker, ['Z701'])
+
+        pep8style = pep8.StyleGuide()
+        count_errors = pep8style.input_file('stdin', lines=['\x00\n'])
+
+        self.assertTrue(sys.stdout[0].startswith("stdin:1:1: E901 TypeError"))
+        self.assertFalse(sys.stderr)
+        self.assertEqual(count_errors, 1)