MDEV-21612 - remove COM_MULTI from server and C/C

The COM_MULTI did not take off. No connector is using it.
Remove related code from server, and client.
If anything it is a step simplification of already-bloated
dispatch_command(), and related code.

19 files changed, 59 insertions, 235 deletions

diff --git a/include/mysql.h.pp b/include/mysql.h.pp
index 4e6240a19ac..e906e4e1a86 100644
--- a/include/mysql.h.pp
+++ b/include/mysql.h.pp
@@ -18,7 +18,7 @@ enum enum_server_command
   COM_SLAVE_WORKER=251,
   COM_SLAVE_IO=252,
   COM_SLAVE_SQL=253,
-  COM_MULTI=254,
+  COM_RESERVED_1=254,
   COM_END=255
 };
 enum enum_indicator_type
diff --git a/include/mysql_com.h b/include/mysql_com.h
index fa5960a377b..b4f1a3c8f94 100644
--- a/include/mysql_com.h
+++ b/include/mysql_com.h
@@ -123,7 +123,7 @@ enum enum_server_command
   COM_SLAVE_WORKER=251,
   COM_SLAVE_IO=252,
   COM_SLAVE_SQL=253,
-  COM_MULTI=254,
+  COM_RESERVED_1=254, /* Old COM_MULTI, now removed */
   /* Must be last */
   COM_END=255
 };
@@ -296,8 +296,10 @@ enum enum_indicator_type
 #define MARIADB_CLIENT_FLAGS_MASK 0xffffffff00000000ULL
 /* Client support progress indicator */
 #define MARIADB_CLIENT_PROGRESS (1ULL << 32)
-/* support COM_MULTI */
-#define MARIADB_CLIENT_COM_MULTI (1ULL << 33)
+
+/* Old COM_MULTI experiment (functionality removed).*/
+#define MARIADB_CLIENT_RESERVED_1 (1ULL << 33)
+
 /* support of array binding */
 #define MARIADB_CLIENT_STMT_BULK_OPERATIONS (1ULL << 34)
 /* support of extended metadata (e.g. type/format information) */
@@ -341,7 +343,6 @@ enum enum_indicator_type
                            CLIENT_SESSION_TRACK |\
                            CLIENT_DEPRECATE_EOF |\
                            CLIENT_CONNECT_ATTRS |\
-                           MARIADB_CLIENT_COM_MULTI |\
                            MARIADB_CLIENT_STMT_BULK_OPERATIONS |\
                            MARIADB_CLIENT_EXTENDED_METADATA|\
                            CLIENT_CAN_HANDLE_EXPIRED_PASSWORDS)
diff --git a/libmysqld/lib_sql.cc b/libmysqld/lib_sql.cc
index b93cd85bfe8..eb3cf9cd8e3 100644
--- a/libmysqld/lib_sql.cc
+++ b/libmysqld/lib_sql.cc
@@ -168,8 +168,7 @@ emb_advanced_command(MYSQL *mysql, enum enum_server_command command,
     arg_length= header_length;
   }
 
-  result= dispatch_command(command, thd, (char *) arg, arg_length, FALSE,
-                           FALSE);
+  result= dispatch_command(command, thd, (char *) arg, arg_length);
   thd->cur_data= 0;
   thd->mysys_var= NULL;
 
@@ -1258,7 +1257,7 @@ bool
 net_send_ok(THD *thd,
             uint server_status, uint statement_warn_count,
             ulonglong affected_rows, ulonglong id, const char *message,
-            bool, bool)
+            bool)
 {
   DBUG_ENTER("emb_net_send_ok");
   MYSQL_DATA *data;
diff --git a/sql/log_event_server.cc b/sql/log_event_server.cc
index fb75bee9f21..a6e02413d4c 100644
--- a/sql/log_event_server.cc
+++ b/sql/log_event_server.cc
@@ -1900,8 +1900,7 @@ int Query_log_event::do_apply_event(rpl_group_info *rgi,
            thd->variables.sql_log_slow= !MY_TEST(global_system_variables.log_slow_disabled_statements & LOG_SLOW_DISABLE_SLAVE);
          }
 
-        mysql_parse(thd, thd->query(), thd->query_length(), &parser_state,
-                    FALSE, FALSE);
+        mysql_parse(thd, thd->query(), thd->query_length(), &parser_state);
         /* Finalize server status flags after executing a statement. */
         thd->update_server_status();
         log_slow_statement(thd);
diff --git a/sql/mysqld.cc b/sql/mysqld.cc
index 63949c6a49c..d4341b17401 100644
--- a/sql/mysqld.cc
+++ b/sql/mysqld.cc
@@ -3330,7 +3330,6 @@ SHOW_VAR com_status_vars[]= {
   {"kill",                 STMT_STATUS(SQLCOM_KILL)},
   {"load",                 STMT_STATUS(SQLCOM_LOAD)},
   {"lock_tables",          STMT_STATUS(SQLCOM_LOCK_TABLES)},
-  {"multi",                COM_STATUS(com_multi)},
   {"optimize",             STMT_STATUS(SQLCOM_OPTIMIZE)},
   {"preload_keys",         STMT_STATUS(SQLCOM_PRELOAD_KEYS)},
   {"prepare_sql",          STMT_STATUS(SQLCOM_PREPARE)},
@@ -3842,7 +3841,7 @@ static int init_common_variables()
     of SQLCOM_ constants.
   */
   compile_time_assert(sizeof(com_status_vars)/sizeof(com_status_vars[0]) - 1 ==
-                     SQLCOM_END + 11);
+                     SQLCOM_END + 10);
 #endif
 
   if (get_options(&remaining_argc, &remaining_argv))
diff --git a/sql/protocol.cc b/sql/protocol.cc
index d565a818f31..ebc0c3815aa 100644
--- a/sql/protocol.cc
+++ b/sql/protocol.cc
@@ -36,7 +36,7 @@ static const unsigned int PACKET_BUFFER_EXTRA_ALLOC= 1024;
 bool net_send_error_packet(THD *, uint, const char *, const char *);
 /* Declared non-static only because of the embedded library. */
 bool net_send_ok(THD *, uint, uint, ulonglong, ulonglong, const char *,
-                 bool, bool);
+                 bool);
 /* Declared non-static only because of the embedded library. */
 bool net_send_eof(THD *thd, uint server_status, uint statement_warn_count);
 #ifndef EMBEDDED_LIBRARY
@@ -211,8 +211,7 @@ bool
 net_send_ok(THD *thd,
             uint server_status, uint statement_warn_count,
             ulonglong affected_rows, ulonglong id, const char *message,
-            bool is_eof,
-            bool skip_flush)
+            bool is_eof)
 {
   NET *net= &thd->net;
   StringBuffer<MYSQL_ERRMSG_SIZE + 10> store;
@@ -285,7 +284,7 @@ net_send_ok(THD *thd,
   DBUG_ASSERT(store.length() <= MAX_PACKET_LENGTH);
 
   error= my_net_write(net, (const unsigned char*)store.ptr(), store.length());
-  if (likely(!error) && (!skip_flush || is_eof))
+  if (likely(!error))
     error= net_flush(net);
 
   thd->server_status&= ~SERVER_SESSION_STATE_CHANGED;
@@ -340,7 +339,7 @@ net_send_eof(THD *thd, uint server_status, uint statement_warn_count)
       (thd->get_command() != COM_BINLOG_DUMP ))
   {
     error= net_send_ok(thd, server_status, statement_warn_count, 0, 0, NULL,
-                       true, false);
+                       true);
     DBUG_RETURN(error);
   }
 
@@ -607,16 +606,14 @@ void Protocol::end_statement()
                    thd->get_stmt_da()->statement_warn_count(),
                    thd->get_stmt_da()->affected_rows(),
                    thd->get_stmt_da()->last_insert_id(),
-                   thd->get_stmt_da()->message(),
-                   thd->get_stmt_da()->skip_flush());
+                   thd->get_stmt_da()->message());
     break;
   case Diagnostics_area::DA_DISABLED:
     break;
   case Diagnostics_area::DA_EMPTY:
   default:
     DBUG_ASSERT(0);
-    error= send_ok(thd->server_status, 0, 0, 0, NULL,
-                   thd->get_stmt_da()->skip_flush());
+    error= send_ok(thd->server_status, 0, 0, 0, NULL);
     break;
   }
   if (likely(!error))
@@ -635,12 +632,12 @@ void Protocol::end_statement()
 
 bool Protocol::send_ok(uint server_status, uint statement_warn_count,
                        ulonglong affected_rows, ulonglong last_insert_id,
-                       const char *message, bool skip_flush)
+                       const char *message)
 {
   DBUG_ENTER("Protocol::send_ok");
   const bool retval=
     net_send_ok(thd, server_status, statement_warn_count,
-                affected_rows, last_insert_id, message, false, skip_flush);
+                affected_rows, last_insert_id, message, false);
   DBUG_RETURN(retval);
 }
 
diff --git a/sql/protocol.h b/sql/protocol.h
index 661ca11d3a1..22d7990a194 100644
--- a/sql/protocol.h
+++ b/sql/protocol.h
@@ -70,7 +70,7 @@ protected:
 
   virtual bool send_ok(uint server_status, uint statement_warn_count,
                        ulonglong affected_rows, ulonglong last_insert_id,
-                       const char *message, bool skip_flush);
+                       const char *message);
 
   virtual bool send_eof(uint server_status, uint statement_warn_count);
 
diff --git a/sql/share/errmsg-utf8.txt b/sql/share/errmsg-utf8.txt
index 275dc1605d8..8b180b466f8 100644
--- a/sql/share/errmsg-utf8.txt
+++ b/sql/share/errmsg-utf8.txt
@@ -7537,13 +7537,10 @@ ER_ALTER_OPERATION_NOT_SUPPORTED_REASON_GIS
 # MariaDB extra error numbers starts from 4000
 skip-to-error-number 4000
 
-ER_COMMULTI_BADCONTEXT 0A000
-        eng "COM_MULTI can't return a result set in the given context"
-        ger "COM_MULTI kann im gegebenen Kontext keine Ergebnismenge zurückgeben"
-        ukr "COM_MULTI не може повернути результати у цьому контексті"
-ER_BAD_COMMAND_IN_MULTI
-        eng "Command '%s' is not allowed for COM_MULTI"
-        ukr "Команда '%s' не дозволена для COM_MULTI"
+ER_UNUSED_26 0A000
+        eng "This error never happens"
+ER_UNUSED_27
+        eng "This error never happens"
 ER_WITH_COL_WRONG_LIST
         eng "WITH column list and SELECT field list have different column counts"
 ER_TOO_MANY_DEFINITIONS_IN_WITH_CLAUSE
diff --git a/sql/slave.cc b/sql/slave.cc
index bd3bab224d3..000900efe61 100644
--- a/sql/slave.cc
+++ b/sql/slave.cc
@@ -347,8 +347,7 @@ gtid_pos_table_creation(THD *thd, plugin_ref engine, LEX_CSTRING *table_name)
   err= parser_state.init(thd, thd->query(), thd->query_length());
   if (err)
     goto end;
-  mysql_parse(thd, thd->query(), thd->query_length(), &parser_state,
-              FALSE, FALSE);
+  mysql_parse(thd, thd->query(), thd->query_length(), &parser_state);
   if (unlikely(thd->is_error()))
     err= 1;
   /* The warning is relevant to 10.3 and earlier. */
diff --git a/sql/sql_class.h b/sql/sql_class.h
index 58a786ed33c..e13b896c820 100644
--- a/sql/sql_class.h
+++ b/sql/sql_class.h
@@ -826,7 +826,6 @@ typedef struct system_status_var
   ulong com_create_tmp_table;
   ulong com_drop_tmp_table;
   ulong com_other;
-  ulong com_multi;
 
   ulong com_stmt_prepare;
   ulong com_stmt_reprepare;
@@ -6902,10 +6901,6 @@ public:
 #define CF_SKIP_WSREP_CHECK     0
 #endif /* WITH_WSREP */
 
-/**
-  Do not allow it for COM_MULTI batch
-*/
-#define CF_NO_COM_MULTI         (1U << 3)
 
 /* Inline functions */
 
diff --git a/sql/sql_error.cc b/sql/sql_error.cc
index b3ef0d89a98..9af57ea6c01 100644
--- a/sql/sql_error.cc
+++ b/sql/sql_error.cc
@@ -302,7 +302,6 @@ void
 Diagnostics_area::reset_diagnostics_area()
 {
   DBUG_ENTER("reset_diagnostics_area");
-  m_skip_flush= FALSE;
 #ifdef DBUG_OFF
   m_can_overwrite_status= FALSE;
   /** Don't take chances in production */
diff --git a/sql/sql_error.h b/sql/sql_error.h
index a0497af78cb..318d5076534 100644
--- a/sql/sql_error.h
+++ b/sql/sql_error.h
@@ -1022,14 +1022,6 @@ public:
   { DBUG_ASSERT(m_status == DA_ERROR || m_status == DA_OK ||
                 m_status == DA_OK_BULK); return m_message; }
 
-  bool skip_flush() const
-  {
-    DBUG_ASSERT(m_status == DA_OK || m_status == DA_OK_BULK);
-    return m_skip_flush;
-  }
-
-  void set_skip_flush()
-  { m_skip_flush= TRUE; }
 
   uint sql_errno() const
   {
@@ -1215,9 +1207,6 @@ private:
   /** Set to make set_error_status after set_{ok,eof}_status possible. */
   bool m_can_overwrite_status;
 
-  /** Skip flushing network buffer after writing OK (for COM_MULTI) */
-  bool m_skip_flush;
-
   /** Message buffer. Can be used by OK or ERROR status. */
   char m_message[MYSQL_ERRMSG_SIZE];
 
diff --git a/sql/sql_parse.cc b/sql/sql_parse.cc
index 8d074e13d1f..4f1b60e977f 100644
--- a/sql/sql_parse.cc
+++ b/sql/sql_parse.cc
@@ -111,9 +111,7 @@
 #include "wsrep_trans_observer.h" /* wsrep transaction hooks */
 
 static bool wsrep_mysql_parse(THD *thd, char *rawbuf, uint length,
-                              Parser_state *parser_state,
-                              bool is_com_multi,
-                              bool is_next_command);
+                              Parser_state *parser_state);
 
 #endif /* WITH_WSREP */
 /**
@@ -389,7 +387,7 @@ const LEX_CSTRING command_name[257]={
   { STRING_WITH_LEN("Slave_worker") }, //251
   { STRING_WITH_LEN("Slave_IO") }, //252
   { STRING_WITH_LEN("Slave_SQL") }, //253
-  { STRING_WITH_LEN("Com_multi") }, //254
+  { 0, 0},
   { STRING_WITH_LEN("Error") }  // Last command number 255
 };
 
@@ -488,7 +486,7 @@ void init_update_queries(void)
   memset(server_command_flags, 0, sizeof(server_command_flags));
 
   server_command_flags[COM_STATISTICS]= CF_SKIP_QUERY_ID | CF_SKIP_QUESTIONS | CF_SKIP_WSREP_CHECK;
-  server_command_flags[COM_PING]=       CF_SKIP_QUERY_ID | CF_SKIP_QUESTIONS | CF_SKIP_WSREP_CHECK | CF_NO_COM_MULTI;
+  server_command_flags[COM_PING]=       CF_SKIP_QUERY_ID | CF_SKIP_QUESTIONS | CF_SKIP_WSREP_CHECK;
 
   server_command_flags[COM_QUIT]= CF_SKIP_WSREP_CHECK;
   server_command_flags[COM_PROCESS_INFO]= CF_SKIP_WSREP_CHECK;
@@ -517,7 +515,6 @@ void init_update_queries(void)
   server_command_flags[COM_STMT_EXECUTE]= CF_SKIP_WSREP_CHECK;
   server_command_flags[COM_STMT_SEND_LONG_DATA]= CF_SKIP_WSREP_CHECK;
   server_command_flags[COM_REGISTER_SLAVE]= CF_SKIP_WSREP_CHECK;
-  server_command_flags[COM_MULTI]= CF_SKIP_WSREP_CHECK | CF_NO_COM_MULTI;
 
   /* Initialize the sql command flags array. */
   memset(sql_command_flags, 0, sizeof(sql_command_flags));
@@ -952,7 +949,7 @@ void execute_init_command(THD *thd, LEX_STRING *init_command,
   save_vio= thd->net.vio;
   thd->net.vio= 0;
   thd->clear_error(1);
-  dispatch_command(COM_QUERY, thd, buf, (uint)len, FALSE, FALSE);
+  dispatch_command(COM_QUERY, thd, buf, (uint)len);
   thd->client_capabilities= save_client_capabilities;
   thd->net.vio= save_vio;
 
@@ -1078,7 +1075,7 @@ int bootstrap(MYSQL_FILE *file)
       break;
     }
 
-    mysql_parse(thd, thd->query(), length, &parser_state, FALSE, FALSE);
+    mysql_parse(thd, thd->query(), length, &parser_state);
 
     bootstrap_error= thd->is_error();
     thd->protocol->end_statement();
@@ -1345,7 +1342,7 @@ bool do_command(THD *thd)
   DBUG_ASSERT(packet_length);
   DBUG_ASSERT(!thd->apc_target.is_enabled());
   return_value= dispatch_command(command, thd, packet+1,
-                                 (uint) (packet_length-1), FALSE, FALSE);
+                                 (uint) (packet_length-1));
   DBUG_ASSERT(!thd->apc_target.is_enabled());
 
 out:
@@ -1456,45 +1453,6 @@ static void wsrep_copy_query(THD *thd)
 }
 #endif /* WITH_WSREP */
 
-/**
-  check COM_MULTI packet
-
-  @param thd             thread handle
-  @param packet          pointer on the packet of commands
-  @param packet_length   length of this packet
-
-  @retval 0 - Error
-  @retval # - Number of commands in the batch
-*/
-
-uint maria_multi_check(THD *thd, char *packet, size_t packet_length)
-{
-  uint counter= 0;
-  DBUG_ENTER("maria_multi_check");
-  while (packet_length)
-  {
-    char *packet_start= packet;
-    size_t subpacket_length= net_field_length((uchar **)&packet_start);
-    size_t length_length= packet_start - packet;
-    // length of command + 3 bytes where that length was stored
-    DBUG_PRINT("info", ("sub-packet length: %zu + %zu  command: %x",
-                        subpacket_length, length_length,
-                        packet_start[3]));
-
-    if (subpacket_length == 0 ||
-        (subpacket_length + length_length) > packet_length)
-    {
-      my_message(ER_UNKNOWN_COM_ERROR, ER_THD(thd, ER_UNKNOWN_COM_ERROR),
-                 MYF(0));
-      DBUG_RETURN(0);
-    }
-
-    counter++;
-    packet= packet_start + subpacket_length;
-    packet_length-= (subpacket_length + length_length);
-  }
-  DBUG_RETURN(counter);
-}
 
 
 #if defined(WITH_ARIA_STORAGE_ENGINE)
@@ -1531,8 +1489,6 @@ public:
   @param packet_length   length of packet + 1 (to show that data is
                          null-terminated) except for COM_SLEEP, where it
                          can be zero.
-  @param is_com_multi    recursive call from COM_MULTI
-  @param is_next_command there will be more command in the COM_MULTI batch
 
   @todo
     set thd->lex->sql_command to SQLCOM_END here.
@@ -1546,8 +1502,7 @@ public:
         COM_QUIT/COM_SHUTDOWN
 */
 bool dispatch_command(enum enum_server_command command, THD *thd,
-		      char* packet, uint packet_length, bool is_com_multi,
-                      bool is_next_command)
+		      char* packet, uint packet_length)
 {
   NET *net= &thd->net;
   bool error= 0;
@@ -1628,14 +1583,6 @@ bool dispatch_command(enum enum_server_command command, THD *thd,
     beginning of each command.
   */
   thd->server_status&= ~SERVER_STATUS_CLEAR_SET;
-  if (is_next_command)
-  {
-    drop_more_results= !MY_TEST(thd->server_status &
-                                SERVER_MORE_RESULTS_EXISTS);
-    thd->server_status|= SERVER_MORE_RESULTS_EXISTS;
-    if (is_com_multi)
-      thd->get_stmt_da()->set_skip_flush();
-  }
 
   if (unlikely(thd->security_ctx->password_expired &&
                command != COM_QUERY &&
@@ -1850,8 +1797,7 @@ bool dispatch_command(enum enum_server_command command, THD *thd,
     if (WSREP(thd))
     {
       if (wsrep_mysql_parse(thd, thd->query(), thd->query_length(),
-                            &parser_state,
-                            is_com_multi, is_next_command))
+                            &parser_state))
       {
         WSREP_DEBUG("Deadlock error for: %s", thd->query());
         mysql_mutex_lock(&thd->LOCK_thd_data);
@@ -1863,8 +1809,7 @@ bool dispatch_command(enum enum_server_command command, THD *thd,
     }
     else
 #endif /* WITH_WSREP */
-      mysql_parse(thd, thd->query(), thd->query_length(), &parser_state,
-                  is_com_multi, is_next_command);
+      mysql_parse(thd, thd->query(), thd->query_length(), &parser_state);
 
     while (!thd->killed && (parser_state.m_lip.found_semicolon != NULL) &&
            ! thd->is_error())
@@ -1948,8 +1893,7 @@ bool dispatch_command(enum enum_server_command command, THD *thd,
       if (WSREP(thd))
       {
         if (wsrep_mysql_parse(thd, beginning_of_next_stmt,
-                              length, &parser_state,
-                              is_com_multi, is_next_command))
+                              length, &parser_state))
         {
           WSREP_DEBUG("Deadlock error for: %s", thd->query());
           mysql_mutex_lock(&thd->LOCK_thd_data);
@@ -1962,8 +1906,7 @@ bool dispatch_command(enum enum_server_command command, THD *thd,
       }
       else
 #endif /* WITH_WSREP */
-      mysql_parse(thd, beginning_of_next_stmt, length, &parser_state,
-                  is_com_multi, is_next_command);
+      mysql_parse(thd, beginning_of_next_stmt, length, &parser_state);
 
     }
 
@@ -2014,13 +1957,6 @@ bool dispatch_command(enum enum_server_command command, THD *thd,
       break;
     }
     packet= arg_end + 1;
-    // thd->reset_for_next_command reset state => restore it
-    if (is_next_command)
-    {
-      thd->server_status|= SERVER_MORE_RESULTS_EXISTS;
-      if (is_com_multi)
-        thd->get_stmt_da()->set_skip_flush();
-    }
 
     lex_start(thd);
     /* Must be before we init the table list. */
@@ -2308,84 +2244,6 @@ bool dispatch_command(enum enum_server_command command, THD *thd,
     general_log_print(thd, command, NullS);
     my_eof(thd);
     break;
-  case COM_MULTI:
-  {
-    uint counter;
-    uint current_com= 0;
-    DBUG_ASSERT(!is_com_multi);
-    if (!(thd->client_capabilities & CLIENT_MULTI_RESULTS))
-    {
-      /* The client does not support multiple result sets being sent back */
-      my_error(ER_COMMULTI_BADCONTEXT, MYF(0));
-      break;
-    }
-
-    if (!(counter= maria_multi_check(thd, packet, packet_length)))
-      break;
-
-    {
-      char *packet_start= packet;
-      /* We have to store next length because it will be destroyed by '\0' */
-      size_t next_subpacket_length= net_field_length((uchar **)&packet_start);
-      size_t next_length_length= packet_start - packet;
-      unsigned char *readbuff= net->buff;
-
-      if (net_allocate_new_packet(net, thd, MYF(0)))
-        break;
-
-      PSI_statement_locker *save_locker= thd->m_statement_psi;
-      sql_digest_state *save_digest= thd->m_digest;
-      thd->m_statement_psi= NULL;
-      thd->m_digest= NULL;
-
-      while (packet_length)
-      {
-        current_com++;
-        size_t subpacket_length= next_subpacket_length + next_length_length;
-        size_t length_length= next_length_length;
-        if (subpacket_length < packet_length)
-        {
-          packet_start= packet + subpacket_length;
-          next_subpacket_length= net_field_length((uchar**)&packet_start);
-          next_length_length= packet_start - (packet + subpacket_length);
-        }
-        /* safety like in do_command() */
-        packet[subpacket_length]= '\0';
-
-        enum enum_server_command subcommand=
-          fetch_command(thd, (packet + length_length));
-
-        if (server_command_flags[subcommand] & CF_NO_COM_MULTI)
-        {
-          my_error(ER_BAD_COMMAND_IN_MULTI, MYF(0),
-                   command_name[subcommand].str);
-          goto com_multi_end;
-        }
-
-        if (dispatch_command(subcommand, thd, packet + (1 + length_length),
-                             (uint)(subpacket_length - (1 + length_length)), TRUE,
-                             (current_com != counter)))
-        {
-          DBUG_ASSERT(thd->is_error());
-          goto com_multi_end;
-        }
-
-        DBUG_ASSERT(subpacket_length <= packet_length);
-        packet+= subpacket_length;
-        packet_length-= (uint)subpacket_length;
-      }
-
-com_multi_end:
-      thd->m_statement_psi= save_locker;
-      thd->m_digest= save_digest;
-
-      /* release old buffer */
-      net_flush(net);
-      DBUG_ASSERT(net->buff == net->write_pos); // nothing to send
-      my_free(readbuff);
-    }
-    break;
-  }
   case COM_SLEEP:
   case COM_CONNECT:				// Impossible here
   case COM_TIME:				// Impossible from client
@@ -2454,11 +2312,8 @@ dispatch_end:
     thd_proc_info(thd, "Updating status");
     /* Finalize server status flags after executing a command. */
     thd->update_server_status();
-    if (command != COM_MULTI)
-    {
-      thd->protocol->end_statement();
-      query_cache_end_of_result(thd);
-    }
+    thd->protocol->end_statement();
+    query_cache_end_of_result(thd);
   }
   if (drop_more_results)
     thd->server_status&= ~SERVER_MORE_RESULTS_EXISTS;
@@ -2486,8 +2341,7 @@ dispatch_end:
   thd->m_statement_psi= NULL;
   thd->m_digest= NULL;
 
-  if (!is_com_multi)
-    thd->packet.shrink(thd->variables.net_buffer_length); // Reclaim some memory
+  thd->packet.shrink(thd->variables.net_buffer_length); // Reclaim some memory
 
   thd->reset_kill_query();  /* Ensure that killed_errmsg is released */
   /*
@@ -7782,9 +7636,7 @@ static void wsrep_prepare_for_autocommit_retry(THD* thd,
 }
 
 static bool wsrep_mysql_parse(THD *thd, char *rawbuf, uint length,
-                              Parser_state *parser_state,
-                              bool is_com_multi,
-                              bool is_next_command)
+                              Parser_state *parser_state)
 {
   bool is_autocommit=
     !thd->in_multi_stmt_transaction_mode()                  &&
@@ -7793,7 +7645,7 @@ static bool wsrep_mysql_parse(THD *thd, char *rawbuf, uint length,
   do
   {
     retry_autocommit= false;
-    mysql_parse(thd, rawbuf, length, parser_state, is_com_multi, is_next_command);
+    mysql_parse(thd, rawbuf, length, parser_state);
 
     /*
       Convert all ER_QUERY_INTERRUPTED errors to ER_LOCK_DEADLOCK
@@ -7899,15 +7751,10 @@ static bool wsrep_mysql_parse(THD *thd, char *rawbuf, uint length,
   @param       thd     Current thread
   @param       rawbuf  Begining of the query text
   @param       length  Length of the query text
-  @param[out]  found_semicolon For multi queries, position of the character of
-                               the next query in the query text.
-  @param is_next_command there will be more command in the COM_MULTI batch
 */
 
 void mysql_parse(THD *thd, char *rawbuf, uint length,
-                 Parser_state *parser_state,
-                 bool is_com_multi,
-                 bool is_next_command)
+                 Parser_state *parser_state)
 {
   int error __attribute__((unused));
   DBUG_ENTER("mysql_parse");
@@ -7932,12 +7779,6 @@ void mysql_parse(THD *thd, char *rawbuf, uint length,
   */
   lex_start(thd);
   thd->reset_for_next_command();
-  if (is_next_command)
-  {
-    thd->server_status|= SERVER_MORE_RESULTS_EXISTS;
-    if (is_com_multi)
-      thd->get_stmt_da()->set_skip_flush();
-  }
 
   if (query_cache_send_result_to_client(thd, rawbuf, length) <= 0)
   {
diff --git a/sql/sql_parse.h b/sql/sql_parse.h
index 6b0ee75b57b..36dc68c292c 100644
--- a/sql/sql_parse.h
+++ b/sql/sql_parse.h
@@ -91,8 +91,7 @@ bool is_log_table_write_query(enum enum_sql_command command);
 bool alloc_query(THD *thd, const char *packet, size_t packet_length);
 void mysql_init_select(LEX *lex);
 void mysql_parse(THD *thd, char *rawbuf, uint length,
-                 Parser_state *parser_state, bool is_com_multi,
-                 bool is_next_command);
+                 Parser_state *parser_state);
 bool mysql_new_select(LEX *lex, bool move_down, SELECT_LEX *sel);
 void create_select_for_variable(THD *thd, LEX_CSTRING *var_name);
 void create_table_set_open_action_and_adjust_tables(LEX *lex);
@@ -103,8 +102,7 @@ int bootstrap(MYSQL_FILE *file);
 int mysql_execute_command(THD *thd);
 bool do_command(THD *thd);
 bool dispatch_command(enum enum_server_command command, THD *thd,
-		      char* packet, uint packet_length,
-                      bool is_com_multi, bool is_next_command);
+		      char* packet, uint packet_length);
 void log_slow_statement(THD *thd);
 bool append_file_to_dir(THD *thd, const char **filename_ptr,
                         const LEX_CSTRING *table_name);
diff --git a/sql/sql_prepare.cc b/sql/sql_prepare.cc
index 93bef049d28..75c3bcd2083 100644
--- a/sql/sql_prepare.cc
+++ b/sql/sql_prepare.cc
@@ -281,7 +281,7 @@ protected:
 
   virtual bool send_ok(uint server_status, uint statement_warn_count,
                        ulonglong affected_rows, ulonglong last_insert_id,
-                       const char *message, bool skip_flush);
+                       const char *message);
 
   virtual bool send_eof(uint server_status, uint statement_warn_count);
   virtual bool send_error(uint sql_errno, const char *err_msg, const char* sqlstate);
@@ -5444,7 +5444,7 @@ bool Protocol_local::send_out_parameters(List<Item_param> *sp_params)
 bool
 Protocol_local::send_ok(uint server_status, uint statement_warn_count,
                         ulonglong affected_rows, ulonglong last_insert_id,
-                        const char *message, bool skip_flush)
+                        const char *message)
 {
   /*
     Just make sure nothing is sent to the client, we have grabbed
diff --git a/sql/wsrep_schema.cc b/sql/wsrep_schema.cc
index 80bc53b1790..08c90e488bd 100644
--- a/sql/wsrep_schema.cc
+++ b/sql/wsrep_schema.cc
@@ -196,7 +196,7 @@ static int execute_SQL(THD* thd, const char* sql, uint length) {
     thd->set_query((char*)sql, length);
     thd->set_query_id(next_query_id());
 
-    mysql_parse(thd, (char*)sql, length, & parser_state, FALSE, FALSE);
+    mysql_parse(thd, (char*)sql, length, & parser_state);
 
     if (thd->is_error()) {
       WSREP_WARN("Wsrep_schema::execute_sql() failed, %d %s\nSQL: %s",
diff --git a/sql/wsrep_sst.cc b/sql/wsrep_sst.cc
index 93b7bc74489..54bb9aa9889 100644
--- a/sql/wsrep_sst.cc
+++ b/sql/wsrep_sst.cc
@@ -1460,7 +1460,7 @@ static int run_sql_command(THD *thd, const char *query)
     return -1;
   }
 
-  mysql_parse(thd, thd->query(), thd->query_length(), &ps, FALSE, FALSE);
+  mysql_parse(thd, thd->query(), thd->query_length(), &ps);
   if (thd->is_error())
   {
     int const err= thd->get_stmt_da()->sql_errno();
diff --git a/storage/spider/spd_table.cc b/storage/spider/spd_table.cc
index e77e1a9261b..835ecbb899a 100644
--- a/storage/spider/spd_table.cc
+++ b/storage/spider/spd_table.cc
@@ -10342,7 +10342,7 @@ void *spider_table_bg_sts_action(
     while (spider_init_queries[i].length && !thd->killed && !thread->killed)
     {
       dispatch_command(COM_QUERY, thd, spider_init_queries[i].str,
-        (uint) spider_init_queries[i].length, FALSE, FALSE);
+        (uint) spider_init_queries[i].length);
       if (unlikely(thd->is_error()))
       {
         fprintf(stderr, "[ERROR] %s\n", spider_stmt_da_message(thd));
diff --git a/tests/mysql_client_test.c b/tests/mysql_client_test.c
index 6a6f626ae8c..e656b85ab65 100644
--- a/tests/mysql_client_test.c
+++ b/tests/mysql_client_test.c
@@ -20986,6 +20986,16 @@ static void test_mdev20261()
 }
 
 
+static void test_execute_direct()
+{
+#ifndef EMBEDDED_LIBRARY
+  MYSQL_STMT* stmt= mysql_stmt_init(mysql);
+  int rc= mariadb_stmt_execute_direct(stmt,"do 1",-1);
+  myquery(rc);
+  mysql_stmt_close(stmt);
+#endif
+}
+
 static struct my_tests_st my_tests[]= {
   { "disable_query_logs", disable_query_logs },
   { "test_view_sp_list_fields", test_view_sp_list_fields },
@@ -21281,6 +21291,7 @@ static struct my_tests_st my_tests[]= {
   { "test_explain_meta", test_explain_meta },
   { "test_mdev18408", test_mdev18408 },
   { "test_mdev20261", test_mdev20261 },
+  { "test_execute_direct", test_execute_direct },
   { 0, 0 }
 };