gh-134064: Fix sys.remote_exec() error checking (GH-134067)

(cherry picked from commit 009e7b3)

Co-authored-by: Victor Stinner <[email protected]>

Author: vstinner

Lib/test/test_sys.py

@@ -2176,6 +2176,13 @@ def test_remote_exec_invalid_pid(self):
         with self.assertRaises(OSError):
             sys.remote_exec(99999, "print('should not run')")
 
+    def test_remote_exec_invalid_script(self):
+        """Test remote exec with invalid script type"""
+        with self.assertRaises(TypeError):
+            sys.remote_exec(0, None)
+        with self.assertRaises(TypeError):
+            sys.remote_exec(0, 123)
+
     def test_remote_exec_syntax_error(self):
         """Test remote exec with syntax error in script"""
         script = '''

Python/sysmodule.c

@@ -2484,7 +2484,7 @@ sys_remote_exec_impl(PyObject *module, int pid, PyObject *script)
     PyObject *path;
     const char *debugger_script_path;
 
-    if (PyUnicode_FSConverter(script, &path) < 0) {
+    if (PyUnicode_FSConverter(script, &path) == 0) {
         return NULL;
     }
     debugger_script_path = PyBytes_AS_STRING(path);