wolfssl: fix error check in shutdown

When trying to send the TLS shutdown, use the return code
to check for the cause.

Reported in Joshua's sarif data

Closes #18729

diff --git a/lib/vtls/wolfssl.c b/lib/vtls/wolfssl.c
index 0cf6e0e4a57a68c80010b1b9a4de3b7c3218f707..ed024356766e79607a7089452c9d64448e4fafcd 100644 (file)
--- a/lib/vtls/wolfssl.c
+++ b/lib/vtls/wolfssl.c
@@ -1921,7 +1921,8 @@ static CURLcode wssl_shutdown(struct Curl_cfilter *cf,
    * was not complete, we are lacking the close notify from the server. */
   if(send_shutdown) {
     wolfSSL_ERR_clear_error();
-    if(wolfSSL_shutdown(wctx->ssl) == 1) {
+    nread = wolfSSL_shutdown(wctx->ssl);
+    if(nread == 1) {
       CURL_TRC_CF(data, cf, "SSL shutdown finished");
       *done = TRUE;
       goto out;