Stubs should not become stubs again in the conversion function, fixes #1475

jedi/inference/gradual/conversion.py

@@ -73,6 +73,12 @@ def _try_stub_to_python_names(names, prefer_stub_to_compiled=False):
                     converted_names = converted.goto(name.get_public_name())
                     if converted_names:
                         for n in converted_names:
+                            if n.get_root_context().is_stub():
+                                # If it's a stub again, it means we're going in
+                                # a circle. Probably some imports make it a
+                                # stub again.
+                                yield name
+                            else:
                                 yield n
                         continue
         yield name

test/test_api/test_completion.py

@@ -431,8 +431,9 @@ def test_completion_cache(Script, module_injector):
     assert cls.docstring() == 'foo()\n\ndoc2'
 
 
-def test_typing_module_completions(Script):
-    for c in Script('import typing; typing.').completions():
+@pytest.mark.parametrize('module', ['typing', 'os'])
+def test_module_completions(Script, module):
+    for c in Script('import {module}; {module}.'.format(module=module)).completions():
         # Just make sure that there are no errors
         c.type
         c.docstring()

test/test_inference/test_gradual/test_conversion.py

@@ -62,3 +62,11 @@ def test_goto_import(Script, skip_pre_python35):
     assert d.is_stub()
     d, = Script(code).goto()
     assert not d.is_stub()
+
+
+def test_os_stat_result(Script):
+    d, = Script('import os; os.stat_result').goto()
+    assert d.is_stub()
+    n = d._name
+    # This should not be a different stub name
+    assert convert_names([n]) == [n]