[3.6] bpo-30876: Relative import from unloaded package now reimports the package (GH-2639) (#2676)

instead of failing with SystemError.

Relative import from non-package now fails with ImportError rather than
SystemError.
(cherry picked from commit 8a9cd20edca7d01b68292036029ae3735ce65edd)

1 files changed, 0 insertions, 4 deletions

diff --git a/Lib/importlib/_bootstrap.py b/Lib/importlib/_bootstrap.py
index f7790c1..bf13e2a 100644
--- a/Lib/importlib/_bootstrap.py
+++ b/Lib/importlib/_bootstrap.py
@@ -919,10 +919,6 @@ def _sanity_check(name, package, level):
         elif not package:
             raise ImportError('attempted relative import with no known parent '
                               'package')
-        elif package not in sys.modules:
-            msg = ('Parent module {!r} not loaded, cannot perform relative '
-                   'import')
-            raise SystemError(msg.format(package))
     if not name and level == 0:
         raise ValueError('Empty module name')