bugfix: fixed keepalive error in cosocket.

Go to openresty/lua-nginx-module#2347 for more details.

Author: zhuizhuhaomeng

src/ngx_stream_lua_socket_tcp.c

@@ -5618,6 +5618,16 @@ ngx_stream_lua_socket_keepalive_close_handler(ngx_event_t *ev)
                    "check stale events");
 
     n = recv(c->fd, buf, 1, MSG_PEEK);
+#if (NGX_STREAM_SSL)
+    /* ignore ssl protocol data like change cipher spec */
+    if (n == 1 && c->ssl != NULL) {
+        n = c->recv(c, (unsigned char *) buf, 1);
+        if (n == NGX_AGAIN) {
+            n = -1;
+            ngx_socket_errno = NGX_EAGAIN;
+        }
+    }
+#endif  /* NGX_STREAM_SSL */
 
     if (n == -1 && ngx_socket_errno == NGX_EAGAIN) {
         /* stale event */

t/129-ssl-socket.t

@@ -1533,11 +1533,11 @@ set keepalive: 1 nil
 --- grep_error_log eval: qr/stream lua ssl (?:set|save|free) session: [0-9A-F]+/
 --- grep_error_log_out eval
 qr/^stream lua ssl save session: ([0-9A-F]+)
-stream lua ssl save session: \1
-stream lua ssl save session: \1
-stream lua ssl free session: \1
-stream lua ssl free session: \1
-stream lua ssl free session: \1
+stream lua ssl save session: ([0-9A-F]+)
+stream lua ssl save session: ([0-9A-F]+)
+stream lua ssl free session: ([0-9A-F]+)
+stream lua ssl free session: ([0-9A-F]+)
+stream lua ssl free session: ([0-9A-F]+)
 $/
 
 --- error_log