fix a problem with dynamic flow information and usages

jedi/api.py

@@ -410,6 +410,8 @@ class Script(object):
 
         :rtype: list of :class:`api_classes.Usage`
         """
+        temp, settings.dynamic_flow_information = \
+            settings.dynamic_flow_information, False
         user_stmt = self._parser.user_stmt
         definitions, search_name = self._goto(add_import_name=True)
         if isinstance(user_stmt, pr.Statement):
@@ -433,6 +435,7 @@ class Script(object):
             else:
                 names.append(api_classes.Usage(d.names[-1], d))
 
+        settings.dynamic_flow_information = temp
         return self._sorted_defs(set(names))
 
     @api_classes._clear_caches_after_call

jedi/dynamic.py

@@ -505,22 +505,24 @@ def check_flow_information(flow, search_name, pos):
 
     ensures that `k` is a string.
     """
+    if not settings.dynamic_flow_information:
+        return None
     result = []
     if isinstance(flow, (pr.Scope, fast_parser.Module)) and not result:
         for ass in reversed(flow.asserts):
             if pos is None or ass.start_pos > pos:
                 continue
-            result = check_statement_information(ass, search_name)
+            result = _check_isinstance_type(ass, search_name)
             if result:
                 break
 
     if isinstance(flow, pr.Flow) and not result:
         if flow.command in ['if', 'while'] and len(flow.inputs) == 1:
-            result = check_statement_information(flow.inputs[0], search_name)
+            result = _check_isinstance_type(flow.inputs[0], search_name)
     return result
 
 
-def check_statement_information(stmt, search_name):
+def _check_isinstance_type(stmt, search_name):
     try:
         commands = stmt.get_commands()
         # this might be removed if we analyze and, etc

jedi/settings.py

@@ -175,6 +175,11 @@ Additional modules in which |jedi| checks if statements are to be found. This
 is practical for IDEs, that want to administrate their modules themselves.
 """
 
+dynamic_flow_information = True
+"""
+Check for `isinstance` and other information to infer a type.
+"""
+
 # ----------------
 # recursions
 # ----------------

test/completion/renaming.py

@@ -213,3 +213,11 @@ class TestProperty:
 #< 11 (1,11), (0,8)
 def f(**kwargs):
     return kwargs
+
+
+# -----------------
+# No result
+# -----------------
+if isinstance(j, int):
+    #< 
+    j