gh-152132: Add embed tests for -m and message SystemExit paths

Add test_run_main_system_exit_module and test_run_main_system_exit_command_message
to _testembed.c and test_embed.py, covering the remaining sys.exit() paths
mentioned in the review feedback (-m module and string message variants).

Author: tangyuan0821

Lib/test/test_embed.py

@@ -439,6 +439,25 @@ def test_run_main_system_exit_file(self):
         finally:
             os.unlink(filename)
 
+    def test_run_main_system_exit_module(self):
+        # gh-152132: same as above, but for the run_module code path.
+        with tempfile.TemporaryDirectory() as tmpdir:
+            mod = os.path.join(tmpdir, "exit_mod.py")
+            with open(mod, "w", encoding="utf-8") as f:
+                f.write("import sys; sys.exit(42)\n")
+            env = dict(os.environ, PYTHONPATH=tmpdir)
+            out, err = self.run_embedded_interpreter(
+                "test_run_main_system_exit_module", env=env)
+            self.assertEqual(out, '')
+            self.assertEqual(err, '')
+
+    def test_run_main_system_exit_command_message(self):
+        # gh-152132: same as above, but with a string exit message.
+        out, err = self.run_embedded_interpreter(
+            "test_run_main_system_exit_command_message")
+        self.assertEqual(out, '')
+        self.assertIn('error message', err)
+
     def test_finalize_structseq(self):
         # bpo-46417: Py_Finalize() clears structseq static types. Check that
         # sys attributes using struct types still work when

Programs/_testembed.c

@@ -2112,6 +2112,50 @@ static int test_run_main_system_exit_file(void)
 }
 
 
+static int test_run_main_system_exit_module(void)
+{
+    // gh-152132: Py_RunMain() must return the SystemExit code instead of
+    // calling exit() directly. The module under -m is resolved from PYTHONPATH
+    // set by the test harness.
+    PyConfig config;
+    PyConfig_InitPythonConfig(&config);
+
+    wchar_t *argv[] = {L"python3", L"-m", L"exit_mod"};
+    config_set_argv(&config, Py_ARRAY_LENGTH(argv), argv);
+    config_set_string(&config, &config.program_name, L"./python3");
+    init_from_config_clear(&config);
+
+    int exitcode = Py_RunMain();
+    if (exitcode != 42) {
+        fprintf(stderr, "expected exit code 42, got %d\n", exitcode);
+        return 1;
+    }
+    return 0;
+}
+
+
+static int test_run_main_system_exit_command_message(void)
+{
+    // gh-152132: Py_RunMain() must return the SystemExit code instead of
+    // calling exit() directly.
+    PyConfig config;
+    PyConfig_InitPythonConfig(&config);
+
+    wchar_t *argv[] = {L"python3", L"-c",
+                       L"import sys; sys.exit('error message')"};
+    config_set_argv(&config, Py_ARRAY_LENGTH(argv), argv);
+    config_set_string(&config, &config.program_name, L"./python3");
+    init_from_config_clear(&config);
+
+    int exitcode = Py_RunMain();
+    if (exitcode != 1) {
+        fprintf(stderr, "expected exit code 1, got %d\n", exitcode);
+        return 1;
+    }
+    return 0;
+}
+
+
 static int test_get_argc_argv(void)
 {
     PyConfig config;
@@ -3008,6 +3052,8 @@ static struct TestCase TestCases[] = {
     {"test_run_main_loop", test_run_main_loop},
     {"test_run_main_system_exit_command", test_run_main_system_exit_command},
     {"test_run_main_system_exit_file", test_run_main_system_exit_file},
+    {"test_run_main_system_exit_module", test_run_main_system_exit_module},
+    {"test_run_main_system_exit_command_message", test_run_main_system_exit_command_message},
     {"test_get_argc_argv", test_get_argc_argv},
     {"test_init_use_frozen_modules", test_init_use_frozen_modules},
     {"test_init_main_interpreter_settings", test_init_main_interpreter_settings},