Don't follow builtin imports anymore by default when follow_imports is on (goto)

CHANGELOG.rst

@@ -7,6 +7,8 @@ Changelog
 +++++++++++++++++++
 
 - Added ``include_builtins`` as a parameter to usages.
+- ``goto_assignments`` has a new ``follow_builtin_imports`` parameter that
+  changes the previous behavior slightly.
 
 0.12.1 (2018-06-30)
 +++++++++++++++++++

jedi/api/__init__.py

@@ -204,20 +204,33 @@ class Script(object):
         # the API.
         return helpers.sorted_definitions(set(defs))
 
-    def goto_assignments(self, follow_imports=False):
+    def goto_assignments(self, follow_imports=False, follow_builtin_imports=False):
         """
         Return the first definition found, while optionally following imports.
         Multiple objects may be returned, because Python itself is a
         dynamic language, which means depending on an option you can have two
         different versions of a function.
 
+        :param follow_imports: The goto call will follow imports.
+        :param follow_builtin_imports: If follow_imports is True will decide if
+            it follow builtin imports.
         :rtype: list of :class:`classes.Definition`
         """
         def filter_follow_imports(names, check):
             for name in names:
                 if check(name):
-                    for result in filter_follow_imports(name.goto(), check):
-                        yield result
+                    new_names = list(filter_follow_imports(name.goto(), check))
+                    found_builtin = False
+                    if follow_builtin_imports:
+                        for new_name in new_names:
+                            if new_name.start_pos is None:
+                                found_builtin = True
+
+                    if found_builtin and not isinstance(name, imports.SubModuleName):
+                        yield name
+                    else:
+                        for new_name in new_names:
+                            yield new_name
                 else:
                     yield name
 

test/test_api/test_api.py

@@ -285,3 +285,11 @@ def test_backslash_continuation_and_bracket(Script):
     column = lines[-1].index('(')
     def_, = Script(code, line=len(lines), column=column).goto_definitions()
     assert def_.name == 'int'
+
+
+def test_goto_follow_builtin_imports(Script):
+    s = Script('import sys; sys')
+    d, = s.goto_assignments(follow_imports=True)
+    assert d.in_builtin_module() is True
+    d, = s.goto_assignments(follow_imports=True, follow_builtin_imports=True)
+    assert d.in_builtin_module() is False