Issue #14285: Do not catch exceptions initializing any ancestor package

The previous fix only handled the case of the parent package of __main__
failing to initialize.

Also make the "Error while finding spec" formatting slightly more appealing,
and document and test that the module name must be absolute.

1 files changed, 9 insertions, 0 deletions

diff --git a/Lib/test/test_runpy.py b/Lib/test/test_runpy.py
index 01f6abd8c5..87c83ecfae 100644
--- a/Lib/test/test_runpy.py
+++ b/Lib/test/test_runpy.py
@@ -197,8 +197,11 @@ class RunModuleTestCase(unittest.TestCase, CodeExecutionMixin):
         self.expect_import_error("sys.imp.eric")
         self.expect_import_error("os.path.half")
         self.expect_import_error("a.bee")
+        # Relative names not allowed
         self.expect_import_error(".howard")
         self.expect_import_error("..eaten")
+        self.expect_import_error(".test_runpy")
+        self.expect_import_error(".unittest")
         # Package without __main__.py
         self.expect_import_error("multiprocessing")
 
@@ -460,6 +463,12 @@ from ..uncle.cousin import nephew
                     self.assertNotIn("finding spec", format(err))
                 else:
                     self.fail("Nothing raised; expected {}".format(name))
+                try:
+                    run_module(mod_name + ".submodule")
+                except exception as err:
+                    self.assertNotIn("finding spec", format(err))
+                else:
+                    self.fail("Nothing raised; expected {}".format(name))
 
     def test_run_package_in_namespace_package(self):
         for depth in range(1, 4):