dns: release sharelock as soon as possible

There is no benefit to holding the data sharelock when freeing the
addrinfo in case it fails, so ensure releaseing it as soon as we can
rather than holding on to it. This also aligns the code with other
consumers of sharelocks.

Closes #3516
Reviewed-by: Daniel Stenberg <daniel@haxx.se>

diff --git a/lib/hostasyn.c b/lib/hostasyn.c
index 6ff60ba61ac14c4ea816c433d1f47e445712c38d..99d872b3525e63eb768ea89c471ea0b878eab5ce 100644 (file)
--- a/lib/hostasyn.c
+++ b/lib/hostasyn.c
@@ -5,7 +5,7 @@
  *                            | (__| |_| |  _ <| |___
  *                             \___|\___/|_| \_\_____|
  *
- * Copyright (C) 1998 - 2018, Daniel Stenberg, <daniel@haxx.se>, et al.
+ * Copyright (C) 1998 - 2019, Daniel Stenberg, <daniel@haxx.se>, et al.
  *
  * This software is licensed as described in the file COPYING, which
  * you should have received as part of this distribution. The terms
@@ -85,14 +85,14 @@ CURLcode Curl_addrinfo_callback(struct connectdata *conn,
       dns = Curl_cache_addr(data, ai,
                             conn->async.hostname,
                             conn->async.port);
+      if(data->share)
+        Curl_share_unlock(data, CURL_LOCK_DATA_DNS);
+
       if(!dns) {
         /* failed to store, cleanup and return error */
         Curl_freeaddrinfo(ai);
         result = CURLE_OUT_OF_MEMORY;
       }
-
-      if(data->share)
-        Curl_share_unlock(data, CURL_LOCK_DATA_DNS);
     }
     else {
       result = CURLE_OUT_OF_MEMORY;