restrict scope of eval parse result

src/server.c

@@ -237,10 +237,10 @@ void rest_start(void *arg) {
 
 }
 
-SEXP nano_eval_res;
+static SEXP nano_parse_eval_res;
 
 void parse_eval_safe(void *data) {
-  nano_eval_res = R_ParseEvalString((const char *) data, R_GlobalEnv);
+  nano_parse_eval_res = R_ParseEvalString((const char *) data, R_GlobalEnv);
 }
 
 void inproc_server(const char* url) {
@@ -252,27 +252,25 @@ void inproc_server(const char* url) {
   if ((xc = nng_rep0_open(&s)) || (xc = nng_listen(s, url, NULL, 0)))
     fatal("unable to set up inproc", xc);
 
-  nano_eval_res = R_BlankScalarString;
-
   for (;;) {
     if ((xc = nng_recvmsg(s, &msg, 0)))
       fatal("inproc recvmsg", xc);
 
     const char *body = nng_msg_body(msg);
     nano_buf buf;
 
+    nano_parse_eval_res = R_BlankScalarString;
     R_ToplevelExec(parse_eval_safe, (void *) body);
 
-    if (TYPEOF(nano_eval_res) == STRSXP) {
-      const char *string = NANO_STRING(nano_eval_res);
+    if (TYPEOF(nano_parse_eval_res) == STRSXP) {
+      const char *string = NANO_STRING(nano_parse_eval_res);
       buf.buf = (unsigned char *) string;
       buf.cur = strlen(string);
     } else {
-      nano_serialize(&buf, nano_eval_res, R_NilValue);
+      nano_serialize(&buf, nano_parse_eval_res, R_NilValue);
     }
     nng_msg_clear(msg);
     nng_msg_append(msg, buf.buf, buf.cur);
-    nano_eval_res = R_BlankScalarString;
     if ((xc = nng_sendmsg(s, msg, 0)))
       fatal("inproc sendmsg", xc);