MDEV-15477: SESSION_SYSVARS_TRACKER does not track last_gtid

register changes of last_gtid

mysql-test/r/mysqltest_tracking_info.result

-SELECT @@session.character_set_client, @@session.character_set_results, @@session.character_set_connection;
-@@session.character_set_client	@@session.character_set_results	@@session.character_set_connection
-latin1	latin1	latin1
-SET @@session.session_track_system_variables='character_set_client,character_set_results,character_set_connection';
+SELECT @@session.character_set_connection;
+@@session.character_set_connection
+latin1
+SET @@session.session_track_system_variables='character_set_connection';
 # tracking info on
 SET NAMES 'utf8';
 -- Tracker : SESSION_TRACK_SYSTEM_VARIABLES
--- character_set_client
--- utf8
 -- character_set_connection
 -- utf8
--- character_set_results
--- utf8
 
 SET NAMES 'big5';
 -- Tracker : SESSION_TRACK_SYSTEM_VARIABLES
--- character_set_client
--- big5
 -- character_set_connection
 -- big5
--- character_set_results
--- big5
 
 # tracking info on once
 SET NAMES 'utf8';
 -- Tracker : SESSION_TRACK_SYSTEM_VARIABLES
--- character_set_client
--- utf8
 -- character_set_connection
 -- utf8
--- character_set_results
--- utf8
 
 SET NAMES 'big5';
 # tracking info on
 SET NAMES 'utf8';
 -- Tracker : SESSION_TRACK_SYSTEM_VARIABLES
--- character_set_client
--- utf8
 -- character_set_connection
 -- utf8
--- character_set_results
--- utf8
 
 # tracking info off once
 SET NAMES 'big5';

mysql-test/r/session_tracker_last_gtid.result

+#
+# MDEV-15477: SESSION_SYSVARS_TRACKER does not track last_gtid
+#
+SET gtid_seq_no=1000;
+SET @@session.session_track_system_variables='last_gtid';
+create table t1 (a int) engine=innodb;
+-- Tracker : SESSION_TRACK_SYSTEM_VARIABLES
+-- last_gtid
+-- 0-1-1000
+
+select @@last_gtid;
+@@last_gtid
+0-1-1000
+-- Tracker : SESSION_TRACK_SYSTEM_VARIABLES
+-- last_gtid
+-- 0-1-1000
+
+insert into t1 values (1);
+-- Tracker : SESSION_TRACK_SYSTEM_VARIABLES
+-- last_gtid
+-- 0-1-1001
+
+select @@last_gtid;
+@@last_gtid
+0-1-1001
+-- Tracker : SESSION_TRACK_SYSTEM_VARIABLES
+-- last_gtid
+-- 0-1-1001
+
+drop table t1;
+-- Tracker : SESSION_TRACK_SYSTEM_VARIABLES
+-- last_gtid
+-- 0-1-1002
+

mysql-test/t/mysqltest_tracking_info.test

@@ -2,8 +2,8 @@
 --source include/no_protocol.inc
 --source include/not_embedded.inc
 
-SELECT @@session.character_set_client, @@session.character_set_results, @@session.character_set_connection;
-SET @@session.session_track_system_variables='character_set_client,character_set_results,character_set_connection';
+SELECT @@session.character_set_connection;
+SET @@session.session_track_system_variables='character_set_connection';
 
 --echo # tracking info on
 --enable_session_track_info

mysql-test/t/session_tracker_last_gtid.test

+--source include/not_embedded.inc
+--source include/have_innodb.inc
+--source include/have_binlog_format_statement.inc
+
+--enable_session_track_info
+
+--echo #
+--echo # MDEV-15477: SESSION_SYSVARS_TRACKER does not track last_gtid
+--echo #
+
+SET gtid_seq_no=1000;
+SET @@session.session_track_system_variables='last_gtid';
+create table t1 (a int) engine=innodb;
+select @@last_gtid;
+insert into t1 values (1);
+select @@last_gtid;
+drop table t1;
+
+--disable_session_track_info

sql/log.cc

@@ -46,6 +46,8 @@
 #include <stdarg.h>
 #include <m_ctype.h>				// For test_if_number
 
+#include <set_var.h> // for Sys_last_gtid_ptr
+
 #ifdef _WIN32
 #include "message.h"
 #endif
@@ -5945,7 +5947,8 @@ MYSQL_BIN_LOG::write_gtid_event(THD *thd, bool standalone,
   }
   if (err)
     DBUG_RETURN(true);
-  thd->last_commit_gtid= gtid;
+
+  thd->set_last_commit_gtid(gtid);
 
   Gtid_log_event gtid_event(thd, seq_no, domain_id, standalone,
                             LOG_EVENT_SUPPRESS_USE_F, is_transactional,

sql/set_var.h

@@ -430,7 +430,7 @@ sql_mode_t expand_sql_mode(sql_mode_t sql_mode);
 bool sql_mode_string_representation(THD *thd, sql_mode_t sql_mode, LEX_STRING *ls);
 int default_regex_flags_pcre(const THD *thd);
 
-extern sys_var *Sys_autocommit_ptr;
+extern sys_var *Sys_autocommit_ptr, *Sys_last_gtid_ptr;
 
 CHARSET_INFO *get_old_charset_by_name(const char *old_name);
 

sql/sql_class.cc

@@ -1190,7 +1190,7 @@ void THD::init(void)
   bzero((char *) &org_status_var, sizeof(org_status_var));
   status_in_global= 0;
   start_bytes_received= 0;
-  last_commit_gtid.seq_no= 0;
+  m_last_commit_gtid.seq_no= 0;
   last_stmt= NULL;
   /* Reset status of last insert id */
   arg_of_last_insert_id_function= FALSE;
@@ -6972,6 +6972,21 @@ THD::signal_wakeup_ready()
   mysql_cond_signal(&COND_wakeup_ready);
 }
 
+void THD::set_last_commit_gtid(rpl_gtid &gtid)
+{
+#ifndef EMBEDDED_LIBRARY
+  bool changed_gtid= (m_last_commit_gtid.seq_no != gtid.seq_no);
+#endif
+  m_last_commit_gtid= gtid;
+#ifndef EMBEDDED_LIBRARY
+  if (changed_gtid &&
+      session_tracker.get_tracker(SESSION_SYSVARS_TRACKER)->is_enabled())
+  {
+    session_tracker.get_tracker(SESSION_SYSVARS_TRACKER)->
+      mark_as_changed(this, (LEX_CSTRING*)Sys_last_gtid_ptr);
+ }
+#endif
+}
 
 void
 wait_for_commit::reinit()

sql/sql_class.h

@@ -4255,7 +4255,13 @@ class THD :public Statement,
     The GTID assigned to the last commit. If no GTID was assigned to any commit
     so far, this is indicated by last_commit_gtid.seq_no == 0.
   */
-  rpl_gtid last_commit_gtid;
+private:
+  rpl_gtid m_last_commit_gtid;
+
+public:
+  rpl_gtid get_last_commit_gtid() { return m_last_commit_gtid; }
+  void set_last_commit_gtid(rpl_gtid &gtid);
+
 
   LF_PINS *tdc_hash_pins;
   LF_PINS *xid_hash_pins;

sql/sys_vars.cc

@@ -1828,6 +1828,8 @@ static Sys_var_last_gtid Sys_last_gtid(
        "or the empty string if none.",
        READ_ONLY sys_var::ONLY_SESSION, NO_CMD_LINE);
 
+export sys_var *Sys_last_gtid_ptr= &Sys_last_gtid; // for check changing
+
 
 uchar *
 Sys_var_last_gtid::session_value_ptr(THD *thd, const LEX_STRING *base)
@@ -1838,8 +1840,9 @@ Sys_var_last_gtid::session_value_ptr(THD *thd, const LEX_STRING *base)
   bool first= true;
 
   str.length(0);
-  if ((thd->last_commit_gtid.seq_no > 0 &&
-       rpl_slave_state_tostring_helper(&str, &thd->last_commit_gtid, &first)) ||
+  rpl_gtid gtid= thd->get_last_commit_gtid();
+  if ((gtid.seq_no > 0 &&
+       rpl_slave_state_tostring_helper(&str, &gtid, &first)) ||
       !(p= thd->strmake(str.ptr(), str.length())))
   {
     my_error(ER_OUT_OF_RESOURCES, MYF(0));