Bug#25511

  "Federated INSERT failures"
  Federated does not correctly handle "INSERT...ON DUPLICATE KEY UPDATE"
  However, implementing such support is not reasonably possible without
  increasing complexity of the storage engine: checking that constraints
  on remote server match local server and parsing error messages.
  This patch causes 'ON DUPLICATE KEY' to fail with ER_DUP_KEY message
  if a conflict occurs and not to fail silently.

include/my_base.h

@@ -168,7 +168,13 @@ enum ha_extra_function {
     These flags are reset by the handler::extra(HA_EXTRA_RESET) call.
   */
   HA_EXTRA_DELETE_CANNOT_BATCH,
-  HA_EXTRA_UPDATE_CANNOT_BATCH
+  HA_EXTRA_UPDATE_CANNOT_BATCH,
+  /*
+    Inform handler that write_row() should immediately report constraint
+    violations because a INSERT...ON DUPLICATE KEY UPDATE is in being
+    performed.
+  */
+  HA_EXTRA_INSERT_WITH_UPDATE
 };
 
 	/* The following is parameter to ha_panic() */

mysql-test/r/federated.result

@@ -1867,6 +1867,21 @@ a	b
 3	Curly
 drop table federated.t1;
 drop table federated.t1;
+create table federated.t1 (a int primary key, b varchar(64))
+DEFAULT CHARSET=utf8;
+create table federated.t1 (a int primary key, b varchar(64))
+ENGINE=FEDERATED
+connection='mysql://root@127.0.0.1:SLAVE_PORT/federated/t1'
+  DEFAULT CHARSET=utf8;
+insert into federated.t1 values (1,"Larry"), (2,"Curly"), (1,"Moe")
+on duplicate key update a=a+100;
+ERROR 23000: Can't write; duplicate key in table 't1'
+select * from federated.t1;
+a	b
+1	Larry
+2	Curly
+drop table federated.t1;
+drop table federated.t1;
 DROP TABLE IF EXISTS federated.t1;
 DROP DATABASE IF EXISTS federated;
 DROP TABLE IF EXISTS federated.t1;

mysql-test/t/federated.test

@@ -1603,4 +1603,30 @@ drop table federated.t1;
 connection slave;
 drop table federated.t1;
 
+#
+# BUG#25511 Federated Insert failures.
+#
+# When the user performs a INSERT...ON DUPLICATE KEY UPDATE, we want
+# it to fail if a duplicate key exists instead of ignoring it.
+#
+connection slave;
+create table federated.t1 (a int primary key, b varchar(64))
+  DEFAULT CHARSET=utf8;
+connection master;
+--replace_result $SLAVE_MYPORT SLAVE_PORT
+eval create table federated.t1 (a int primary key, b varchar(64))
+  ENGINE=FEDERATED
+  connection='mysql://root@127.0.0.1:$SLAVE_MYPORT/federated/t1'
+  DEFAULT CHARSET=utf8;
+
+--error ER_DUP_KEY
+insert into federated.t1 values (1,"Larry"), (2,"Curly"), (1,"Moe")
+on duplicate key update a=a+100;
+select * from federated.t1;
+
+drop table federated.t1;
+connection slave;
+drop table federated.t1;
+
+
 source include/federated_cleanup.inc;

sql/ha_federated.cc

@@ -1627,7 +1627,7 @@ int ha_federated::write_row(byte *buf)
   */
   if (replace_duplicates)
     insert_string.append(STRING_WITH_LEN("REPLACE INTO "));
-  else if (ignore_duplicates)
+  else if (ignore_duplicates && !insert_dup_update)
     insert_string.append(STRING_WITH_LEN("INSERT IGNORE INTO "));
   else
     insert_string.append(STRING_WITH_LEN("INSERT INTO "));
@@ -2548,6 +2548,7 @@ int ha_federated::extra(ha_extra_function operation)
     ignore_duplicates= TRUE;
     break;
   case HA_EXTRA_NO_IGNORE_DUP_KEY:
+    insert_dup_update= FALSE;
     ignore_duplicates= FALSE;
     break;
   case HA_EXTRA_WRITE_CAN_REPLACE:
@@ -2556,7 +2557,11 @@ int ha_federated::extra(ha_extra_function operation)
   case HA_EXTRA_WRITE_CANNOT_REPLACE:
     replace_duplicates= FALSE;
     break;
+  case HA_EXTRA_INSERT_WITH_UPDATE:
+    insert_dup_update= TRUE;
+    break;
   case HA_EXTRA_RESET:
+    insert_dup_update= FALSE;
     ignore_duplicates= FALSE;
     replace_duplicates= FALSE;
     break;
@@ -2699,6 +2704,9 @@ int ha_federated::stash_remote_error()
   DBUG_ENTER("ha_federated::stash_remote_error()");
   remote_error_number= mysql_errno(mysql);
   strmake(remote_error_buf, mysql_error(mysql), sizeof(remote_error_buf)-1);
+  if (remote_error_number == ER_DUP_ENTRY ||
+      remote_error_number == ER_DUP_KEY)
+    DBUG_RETURN(HA_ERR_FOUND_DUPP_KEY);
   DBUG_RETURN(HA_FEDERATED_ERROR_WITH_REMOTE_SYSTEM);
 }
 

sql/ha_federated.h

@@ -158,6 +158,7 @@ class ha_federated: public handler
   int remote_error_number;
   char remote_error_buf[FEDERATED_QUERY_BUFFER_SIZE];
   bool ignore_duplicates, replace_duplicates;
+  bool insert_dup_update;
 
 private:
   /*

sql/sql_insert.cc

@@ -715,6 +715,8 @@ bool mysql_insert(THD *thd,TABLE_LIST *table_list,
     */
     table->file->extra(HA_EXTRA_RETRIEVE_ALL_COLS);
   }
+  if (duplic == DUP_UPDATE)
+    table->file->extra(HA_EXTRA_INSERT_WITH_UPDATE);
   /*
     let's *try* to start bulk inserts. It won't necessary
     start them as values_list.elements should be greater than
@@ -2434,6 +2436,8 @@ bool Delayed_insert::handle_inserts(void)
       table->file->extra(HA_EXTRA_WRITE_CAN_REPLACE);
       using_opt_replace= 1;
     }
+    if (info.handle_duplicates == DUP_UPDATE)
+      table->file->extra(HA_EXTRA_INSERT_WITH_UPDATE);
     thd.clear_error(); // reset error for binlog
     if (write_record(&thd, table, &info))
     {
@@ -2761,6 +2765,8 @@ select_insert::prepare(List<Item> &values, SELECT_LEX_UNIT *u)
       table->file->extra(HA_EXTRA_WRITE_CAN_REPLACE);
     table->file->extra(HA_EXTRA_RETRIEVE_ALL_COLS);
   }
+  if (info.handle_duplicates == DUP_UPDATE)
+    table->file->extra(HA_EXTRA_INSERT_WITH_UPDATE);
   thd->no_trans_update.stmt= FALSE;
   thd->abort_on_warning= (!info.ignore &&
                           (thd->variables.sql_mode &
@@ -3218,6 +3224,8 @@ select_create::prepare(List<Item> &values, SELECT_LEX_UNIT *u)
       table->file->extra(HA_EXTRA_WRITE_CAN_REPLACE);
     table->file->extra(HA_EXTRA_RETRIEVE_ALL_COLS);
   }
+  if (info.handle_duplicates == DUP_UPDATE)
+    table->file->extra(HA_EXTRA_INSERT_WITH_UPDATE);
   if (!thd->prelocked_mode)
     table->file->start_bulk_insert((ha_rows) 0);
   thd->no_trans_update.stmt= FALSE;