Treat return values from sm_eval as errors only if the

top-level property is "error" or the return value is
a list whose only entry is the tuple {"error":"notfound"}.

c_src/spidermonkey_drv.c

@@ -115,7 +115,7 @@ void run_js(void *jsargs) {
     char *filename = read_string(&data);
     char *code = read_string(&data);
     result = sm_eval(dd->vm, filename, code, 1);
-    if (strstr(result, "{\"error\"") != NULL) {
+    if ((strncmp(result, "[{\"error\":\"notfound\"}]", 22) == 0) || (strncmp(result, "{\"error\"", 8) == 0)) {
       send_error_string_response(dd, call_id, result);
     }
     else {