1 files changed, 28 insertions, 6 deletions

diff --git a/sql/ha_federated.cc b/sql/ha_federated.cc
index ac1e0962ffb..d414dc34f02 100644
--- a/sql/ha_federated.cc
+++ b/sql/ha_federated.cc
@@ -643,13 +643,20 @@ static int parse_url(FEDERATED_SHARE *share, TABLE *table,
   if ((strchr(share->table_name, '/')))
     goto error;
 
+  /*
+    If hostname is omitted, we set it to NULL. According to
+    mysql_real_connect() manual:
+    The value of host may be either a hostname or an IP address.
+    If host is NULL or the string "localhost", a connection to the
+    local host is assumed.
+  */
   if (share->hostname[0] == '\0')
     share->hostname= NULL;
 
   if (!share->port)
   {
-    if (strcmp(share->hostname, my_localhost) == 0)
-      share->socket= my_strdup(MYSQL_UNIX_ADDR, MYF(0));
+    if (!share->hostname || strcmp(share->hostname, my_localhost) == 0)
+      share->socket= (char*) MYSQL_UNIX_ADDR;
     else
       share->port= MYSQL_PORT;
   }
@@ -1094,10 +1101,20 @@ bool ha_federated::create_where_from_key(String *to,
       {
         if (*ptr++)
         {
+          /*
+            We got "IS [NOT] NULL" condition against nullable column. We
+            distinguish between "IS NOT NULL" and "IS NULL" by flag. For
+            "IS NULL", flag is set to HA_READ_KEY_EXACT.
+          */
           if (emit_key_part_name(&tmp, key_part) ||
-              tmp.append(FEDERATED_ISNULL))
+              tmp.append(ranges[i]->flag == HA_READ_KEY_EXACT ?
+                         FEDERATED_ISNULL : " IS NOT NULL "))
             DBUG_RETURN(1);
-          continue;
+          /*
+            We need to adjust pointer and length to be prepared for next
+            key part. As well as check if this was last key part.
+          */
+          goto prepare_for_next_key_part;
         }
       }
 
@@ -1199,12 +1216,18 @@ bool ha_federated::create_where_from_key(String *to,
       if (tmp.append(FEDERATED_CLOSEPAREN))
         DBUG_RETURN(1);
 
+prepare_for_next_key_part:
       if (store_length >= length)
         break;
       DBUG_PRINT("info", ("remainder %d", remainder));
       DBUG_ASSERT(remainder > 1);
       length-= store_length;
-      ptr+= store_length;
+      /*
+        For nullable columns, null-byte is already skipped before, that is
+        ptr was incremented by 1. Since store_length still counts null-byte,
+        we need to subtract 1 from store_length.
+      */
+      ptr+= store_length - test(key_part->null_bit);
       if (tmp.append(FEDERATED_AND))
         DBUG_RETURN(1);
 
@@ -1319,7 +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));