Cleanup SameEnvironment and use the same logic for creation in virtualenvs

jedi/api/environment.py

@@ -153,9 +153,9 @@ def _get_virtual_env_from_var():
     variable is considered to be safe / controlled by the user solely.
     """
     var = os.environ.get('VIRTUAL_ENV')
-    if var is not None:
+    if var:
         if var == sys.prefix:
-            return SameEnvironment()
+            return _try_get_same_env()
 
         try:
             return create_environment(var, safe=False)
@@ -184,6 +184,10 @@ def get_default_environment():
     if virtual_env is not None:
         return virtual_env
 
+    return _try_get_same_env()
+
+
+def _try_get_same_env():
     env = SameEnvironment()
     if not os.path.basename(env.executable).lower().startswith('python'):
         # This tries to counter issues with embedding. In some cases (e.g.

test/test_api/test_environment.py

@@ -131,11 +131,13 @@ def test_get_default_environment_from_env_does_not_use_safe(tmpdir, monkeypatch)
     assert env.path == 'fake'
 
 
-def test_get_default_environment_when_embedded(monkeypatch):
+@pytest.mark.parametrize('virtualenv', ['', 'fufuuuuu', sys.prefix])
+def test_get_default_environment_when_embedded(monkeypatch, virtualenv):
     # When using Python embedded, sometimes the executable is not a Python
     # executable.
     executable_name = 'RANDOM_EXE'
     monkeypatch.setattr(sys, 'executable', executable_name)
+    monkeypatch.setenv('VIRTUAL_ENV', virtualenv)
     env = get_default_environment()
     assert env.executable != executable_name