diff --git a/parso/python/normalizer.py b/parso/python/normalizer.py
index 993848f..c32bb97 100644
--- a/parso/python/normalizer.py
+++ b/parso/python/normalizer.py
@@ -430,7 +430,7 @@ class ErrorFinder(Normalizer):
                     self._add_syntax_error(message % p.name.value, p.name)
                 param_names.add(p.name.value)
 
-                if p.default is None:
+                if p.default is None and not p.star_count:
                     if default_only:
                         # def f(x=3, y): pass
                         message = "non-default argument follows default argument"
@@ -510,6 +510,9 @@ class ErrorFinder(Normalizer):
 
         yield
 
+        if node.type == 'suite':
+            self._indentation_count -= 1
+
     def visit_leaf(self, leaf):
         if leaf.type == 'error_leaf':
             if leaf.original_type in ('indent', 'error_dedent'):
@@ -597,7 +600,7 @@ class ErrorFinder(Normalizer):
         elif leaf.value == 'break':
             in_loop = False
             for block in self._context.blocks:
-                if block.type == 'for_stmt':
+                if block.type in ('for_stmt', 'while_stmt'):
                     in_loop = True
             if not in_loop:
                 self._add_syntax_error("'break' outside loop", leaf)
diff --git a/test/test_file_python_errors.py b/test/test_file_python_errors.py
new file mode 100644
index 0000000..6c733a2
--- /dev/null
+++ b/test/test_file_python_errors.py
@@ -0,0 +1,23 @@
+import os
+
+import parso
+
+
+def get_python_files(path):
+    for dir_path, dir_names, file_names in os.walk(path):
+        for file_name in file_names:
+            if file_name.endswith('.py'):
+                yield os.path.join(dir_path, file_name)
+
+
+def test_parso_files(each_version):
+    """
+    There are obviously no syntax erros in the Python code of parso. However
+    parso should output the same for all versions.
+    """
+    grammar = parso.load_grammar(version=each_version)
+    path = os.path.dirname(os.path.dirname(__file__)) + '/parso'
+    for file in get_python_files(path):
+        tree = grammar.parse(path=file)
+        errors = list(tree._iter_errors(grammar))
+        assert not errors