BUG#35509 - Federated leaks memory when connecting to

            localhost/default port

When creating federated table that points to unspecified host or
localhost on unspecified port or port is 0, small memory leak occurs.

This happens because we make a copy of unix socket path, which is
never freed.

With this fix we do not make a copy of unix socket path, instead
share->socket points to MYSQL_UNIX_ADDR constant directly.

This fix is covered by a test case for BUG34788.

Affects 5.0 only.


mysql-test/t/federated.test:
  A test case for BUG#35509.
sql/ha_federated.cc:
  When creating federated table we call parse_url() to check if connect
  string is correct. parse_url() may make a copy of unix socket path if
  port is not specified or 0 and host is not specified or 'localhost'.
  This copy is never freed.
  
  As there is no need to make a copy of unix socket path, let
  share->socket point to MYSQL_UNIX_ADDR directly.

mysql-test/t/federated.test

@@ -1742,6 +1742,11 @@ DROP TABLE t1;
 # BUG#34788 - malformed federated connection url is not handled correctly -
 #             crashes server !
 #
+# also tests
+#
+# BUG#35509 - Federated leaks memory when connecting to localhost/default
+#             port
+#
 CREATE TABLE t1 (a INT) ENGINE=federated CONNECTION='mysql://@:://';
 DROP TABLE t1;
 

sql/ha_federated.cc

@@ -656,7 +656,7 @@ static int parse_url(FEDERATED_SHARE *share, TABLE *table,
   if (!share->port)
   {
     if (!share->hostname || strcmp(share->hostname, my_localhost) == 0)
-      share->socket= my_strdup(MYSQL_UNIX_ADDR, MYF(0));
+      share->socket= (char*) MYSQL_UNIX_ADDR;
     else
       share->port= MYSQL_PORT;
   }
@@ -1342,7 +1342,6 @@ static int free_share(FEDERATED_SHARE *share)
   {
     hash_delete(&federated_open_tables, (byte*) share);
     my_free((gptr) share->scheme, MYF(MY_ALLOW_ZERO_PTR));
-    my_free((gptr) share->socket, MYF(MY_ALLOW_ZERO_PTR));
     thr_lock_delete(&share->lock);
     VOID(pthread_mutex_destroy(&share->mutex));
     my_free((gptr) share, MYF(0));