bpo-43381: Add frozen module co_lines() test

Lib/test/test_frozen.py

@@ -7,23 +7,36 @@
 #
 # The test_importlib also tests this module but because those tests
 # are much more complicated, it might be unclear why they are failing.
-# Invalid marshalled data in frozen.c could case the interpreter to
-# crash when __hello__ is imported.
 
 import sys
 import unittest
-from test.support import captured_stdout
+from test.support import captured_stdout, impl_detail
 
 
 class TestFrozen(unittest.TestCase):
     def test_frozen(self):
         name = '__hello__'
         if name in sys.modules:
             del sys.modules[name]
+        # Invalid marshalled data in frozen.c could case the interpreter to
+        # crash when __hello__ is imported.  Ensure we can import the module
+        # and that it generates the correct output.
         with captured_stdout() as out:
             import __hello__
         self.assertEqual(out.getvalue(), 'Hello world!\n')
 
+    @impl_detail('code object line table', cpython=True)
+    def test_frozen_linetab(self):
+        with captured_stdout():
+            import __hello__
+            # get the code object for the module
+            co = __hello__.__spec__.loader.get_code('__hello__')
+        # verify that line number table is as expected.  This is intended to
+        # catch bugs like bpo-43372.  The __hello__ module would import
+        # successfully but the frozen code was out-of-date and co_lines()
+        # would cause a crash.
+        self.assertEqual(list(co.co_lines()), [(0, 4, 1), (4, 16, 2)])
+
 
 if __name__ == '__main__':
     unittest.main()

Misc/NEWS.d/next/Tests/2021-03-02-16-55-37.bpo-43381.45RrT9.rst

@@ -0,0 +1 @@
+Add a small test for frozen code co_lines().