按提示词结论补参数文件默认回落锁

core/tests/cnc_sim_api_smoke.cpp

@@ -6163,6 +6163,48 @@ int main() {
                      "expected LinuxCNC rotary/UVW persistent numbered parameters to reload from parameter file");
     }
 
+    const std::string parameter_env_leak_guard_var_path = temp_dir.file("parameter_env_leak_guard.var");
+    {
+        std::ofstream var_file(parameter_env_leak_guard_var_path);
+        var_file << "5001\t17.000000\n";
+    }
+    {
+        ScopedEnv var_env("CNC_SIM_RS274_VAR", parameter_env_leak_guard_var_path.c_str());
+        const char parameter_env_leak_guard_set_program[] =
+            "#5001 = 91\n"
+            "M30\n";
+        events.clear();
+        ok &= expect(cnc_sim_parse_program(sim,
+                                           parameter_env_leak_guard_set_program,
+                                           sizeof(parameter_env_leak_guard_set_program) - 1) == 0,
+                     cnc_sim_last_error(sim));
+    }
+    {
+        const char parameter_env_default_check_program[] =
+            "F100\n"
+            "O10 if [#5001 EQ 91]\n"
+            "G1 X1\n"
+            "O10 endif\n";
+        events.clear();
+        ok &= expect(cnc_sim_parse_program(sim,
+                                           parameter_env_default_check_program,
+                                           sizeof(parameter_env_default_check_program) - 1) == 0,
+                     cnc_sim_last_error(sim));
+        bool saw_stale_env_parameter = false;
+        for (const auto &event : events) {
+            saw_stale_env_parameter = saw_stale_env_parameter ||
+                                      (event.type == CNC_SIM_EVENT_LINEAR_FEED &&
+                                       event.line == 3 &&
+                                       near(event.end.x, 1.0));
+        }
+        // LinuxCNC source basis: rs274ngc_pre.cc rs274_ngc_init() falls back
+        // to RS274NGC_PARAMETER_FILE_NAME_DEFAULT when the external parameter
+        // file name is empty. The project env override must not persist after
+        // CNC_SIM_RS274_VAR is unset.
+        ok &= expect(!saw_stale_env_parameter,
+                     "expected LinuxCNC parameter env override not to leak into default parses");
+    }
+
     const char volatile_global_set_program[] =
         "#31 = 7\n"
         "M30\n";