Bug#57306 SHOW PROCESSLIST does not display string literals well.

Problem: Extended characters outside of ASCII range where not displayed
properly in SHOW PROCESSLIST, because thd_info->query was always sent as 
system_character_set (utf8). This was wrong, because query buffer
is never converted to utf8 - it is always have client character set.

Fix: sending query buffer using query character set

  @ sql/sql_class.cc
  @ sql/sql_class.h
    Introducing a new class CSET_STRING, a LEX_STRING with character set.
    Adding set_query(&CSET_STRING)
    Adding reset_query(), to use instead of set_query(0, NULL).

  @ sql/event_data_objects.cc
    Using reset_query()

  @ sql/log_event.cc
    Using reset_query()
    Adding charset argument to set_query_and_id().

  @ sql/slave.cc
    Using reset_query().

  @ sql/sp_head.cc
    Changing backing up and restore code to use CSET_STRING.

  @ sql/sql_audit.h
    Using CSET_STRING.
    In the "else" branch it's OK not to use
    global_system_variables.character_set_client.
    &my_charset_latin1, which is set in constructor, is fine
    (verified with Sergey Vojtovich).

  @ sql/sql_insert.cc
    Using set_query() with proper character set: table_name is utf8.

  @ sql/sql_parse.cc
    Adding character set argument to set_query_and_id().
    (This is the main point where thd->charset() is stored
     into thd->query_string.cs, for use in "SHOW PROCESSLIST".)
    Using reset_query().
    
  @ sql/sql_prepare.cc
    Storing client character set into thd->query_string.cs.

  @ sql/sql_show.cc
    Using CSET_STRING to fetch and send charset-aware query information
    from threads.

  @ storage/myisam/ha_myisam.cc
    Using set_query() with proper character set: table_name is utf8.

  @ mysql-test/r/show_check.result
  @ mysql-test/t/show_check.test
    Adding tests

mysql-test/r/show_check.result

@@ -1514,3 +1514,27 @@ ALTER TABLE t1 CHARACTER SET = utf8;
 COMMIT;
 DROP TRIGGER t1_bi;
 DROP TABLE t1;
+#
+# Bug#57306 SHOW PROCESSLIST does not display string literals well.
+#
+SET NAMES latin1;
+SELECT GET_LOCK('t', 1000);
+GET_LOCK('t', 1000)
+1
+SET NAMES latin1;
+SELECT GET_LOCK('t',1000) AS 'óóóó';;
+SHOW PROCESSLIST;
+Id	User	Host	db	Command	Time	State	Info
+###	root	localhost	test	Query	###	###	SHOW PROCESSLIST
+###	root	localhost	test	Query	###	###	SELECT GET_LOCK('t',1000) AS 'óóóó'
+SET NAMES utf8;
+SHOW PROCESSLIST;
+Id	User	Host	db	Command	Time	State	Info
+###	root	localhost	test	Query	###	###	SHOW PROCESSLIST
+###	root	localhost	test	Query	###	###	SELECT GET_LOCK('t',1000) AS 'óóóó'
+SELECT RELEASE_LOCK('t');
+RELEASE_LOCK('t')
+1
+óóóó
+1
+SET NAMES latin1;

mysql-test/t/show_check.test

@@ -1328,3 +1328,30 @@ disconnect con1;
 # Wait till all disconnects are completed
 --source include/wait_until_count_sessions.inc
 
+--echo #
+--echo # Bug#57306 SHOW PROCESSLIST does not display string literals well.
+--echo #
+
+SET NAMES latin1;
+SELECT GET_LOCK('t', 1000);
+--connect (con1,localhost,root,,)
+--connection con1
+SET NAMES latin1;
+--send SELECT GET_LOCK('t',1000) AS 'óóóó';
+--connection default
+# Make sure con1 has switched from "SET NAMES" to "SELECT GET_LOCK"
+let $wait_timeout= 10;
+let $wait_condition= SELECT COUNT(*) FROM INFORMATION_SCHEMA.PROCESSLIST WHERE INFO LIKE '%GET_LOCK%' AND ID != CONNECTION_ID();
+--source include/wait_condition.inc
+--replace_column 1 ### 6 ### 7 ###
+SHOW PROCESSLIST;
+SET NAMES utf8;
+--replace_column 1 ### 6 ### 7 ###
+SHOW PROCESSLIST;
+SELECT RELEASE_LOCK('t');
+--connection con1
+--reap
+--disconnect con1
+--connection default
+SET NAMES latin1;
+

sql/event_data_objects.cc

@@ -1526,7 +1526,7 @@ end:
   thd->end_statement();
   thd->cleanup_after_query();
   /* Avoid races with SHOW PROCESSLIST */
-  thd->set_query(NULL, 0);
+  thd->reset_query();
 
   DBUG_PRINT("info", ("EXECUTED %s.%s  ret: %d", dbname.str, name.str, ret));
 

sql/log_event.cc

@@ -3241,7 +3241,8 @@ int Query_log_event::do_apply_event(Relay_log_info const *rli,
   if (is_trans_keyword() || rpl_filter->db_ok(thd->db))
   {
     thd->set_time((time_t)when);
-    thd->set_query_and_id((char*)query_arg, q_len_arg, next_query_id());
+    thd->set_query_and_id((char*)query_arg, q_len_arg,
+                          thd->charset(), next_query_id());
     thd->variables.pseudo_thread_id= thread_id;		// for temp tables
     DBUG_PRINT("query",("%s", thd->query()));
 
@@ -3293,6 +3294,18 @@ int Query_log_event::do_apply_event(Relay_log_info const *rli,
             goto compare_errors;
           }
           thd->update_charset(); // for the charset change to take effect
+          /*
+            Reset thd->query_string.cs to the newly set value.
+            Note, there is a small flaw here. For a very short time frame
+            if the new charset is different from the old charset and
+            if another thread executes "SHOW PROCESSLIST" after
+            the above thd->set_query_and_id() and before this thd->set_query(),
+            and if the current query has some non-ASCII characters,
+            the another thread may see some '?' marks in the PROCESSLIST
+            result. This should be acceptable now. This is a reminder
+            to fix this if any refactoring happens here sometime.
+          */
+          thd->set_query((char*) query_arg, q_len_arg, thd->charset());
         }
       }
       if (time_zone_len)
@@ -3513,7 +3526,7 @@ end:
   */
   thd->catalog= 0;
   thd->set_db(NULL, 0);                 /* will free the current database */
-  thd->set_query(NULL, 0);
+  thd->reset_query();
   DBUG_PRINT("info", ("end: query= 0"));
   /*
     As a disk space optimization, future masters will not log an event for
@@ -4750,7 +4763,7 @@ int Load_log_event::do_apply_event(NET* net, Relay_log_info const *rli,
   new_db.str= (char *) rpl_filter->get_rewrite_db(db, &new_db.length);
   thd->set_db(new_db.str, new_db.length);
   DBUG_ASSERT(thd->query() == 0);
-  thd->set_query_inner(NULL, 0);               // Should not be needed
+  thd->reset_query_inner();                    // Should not be needed
   thd->is_slave_error= 0;
   clear_all_errors(thd, const_cast<Relay_log_info*>(rli));
 
@@ -4944,7 +4957,7 @@ error:
   const char *remember_db= thd->db;
   thd->catalog= 0;
   thd->set_db(NULL, 0);                   /* will free the current database */
-  thd->set_query(NULL, 0);
+  thd->reset_query();
   thd->stmt_da->can_overwrite_status= TRUE;
   thd->is_error() ? trans_rollback_stmt(thd) : trans_commit_stmt(thd);
   thd->stmt_da->can_overwrite_status= FALSE;

sql/slave.cc

@@ -3011,7 +3011,7 @@ err:
   sql_print_information("Slave I/O thread exiting, read up to log '%s', position %s",
                   IO_RPL_LOG_NAME, llstr(mi->master_log_pos,llbuff));
   RUN_HOOK(binlog_relay_io, thread_stop, (thd, mi));
-  thd->set_query(NULL, 0);
+  thd->reset_query();
   thd->reset_db(NULL, 0);
   if (mysql)
   {
@@ -3401,7 +3401,7 @@ the slave SQL thread with \"SLAVE START\". We stopped at log \
     variables is supposed to set them to 0 before terminating)).
   */
   thd->catalog= 0;
-  thd->set_query(NULL, 0);
+  thd->reset_query();
   thd->reset_db(NULL, 0);
   thd_proc_info(thd, "Waiting for slave mutex on exit");
   mysql_mutex_lock(&rli->run_lock);

sql/sp_head.cc

@@ -3065,8 +3065,6 @@ int sp_instr::exec_core(THD *thd, uint *nextp)
 int
 sp_instr_stmt::execute(THD *thd, uint *nextp)
 {
-  char *query;
-  uint32 query_length;
   int res;
   DBUG_ENTER("sp_instr_stmt::execute");
   DBUG_PRINT("info", ("command: %d", m_lex_keeper.sql_command()));
@@ -3074,8 +3072,7 @@ sp_instr_stmt::execute(THD *thd, uint *nextp)
   if (check_stack_overrun(thd, STACK_MIN_SIZE, (uchar*)&res))
     DBUG_RETURN(TRUE);
 
-  query= thd->query();
+  const CSET_STRING query_backup= thd->query_string;
-  query_length= thd->query_length();
 #if defined(ENABLED_PROFILING)
   /* This s-p instr is profilable and will be captured. */
   thd->profiling.set_query_source(m_query.str, m_query.length);
@@ -3105,7 +3102,7 @@ sp_instr_stmt::execute(THD *thd, uint *nextp)
     }
     else
       *nextp= m_ip+1;
-    thd->set_query(query, query_length);
+    thd->set_query(query_backup);
     thd->query_name_consts= 0;
 
     if (!thd->is_error())

sql/sql_audit.h

@@ -99,32 +99,29 @@ void mysql_audit_general(THD *thd, uint event_subtype,
   {
     time_t time= my_time(0);
     uint msglen= msg ? strlen(msg) : 0;
-    const char *query, *user;
+    const char *user;
-    uint querylen, userlen;
+    uint userlen;
     char user_buff[MAX_USER_HOST_SIZE];
-    CHARSET_INFO *clientcs;
+    CSET_STRING query;
     ha_rows rows;
 
     if (thd)
     {
-      query= thd->query();
+      query= thd->query_string;
-      querylen= thd->query_length();
       user= user_buff;
       userlen= make_user_name(thd, user_buff);
-      clientcs= thd->variables.character_set_client;
       rows= thd->warning_info->current_row_for_warning();
     }
     else
     {
-      query= user= 0;
+      user= 0;
-      querylen= userlen= 0;
+      userlen= 0;
-      clientcs= global_system_variables.character_set_client;
       rows= 0;
     }
 
     mysql_audit_notify(thd, MYSQL_AUDIT_GENERAL_CLASS, event_subtype,
                        error_code, time, user, userlen, msg, msglen,
-                       query, querylen, clientcs, rows);
+                       query.str(), query.length(), query.charset(), rows);
   }
 #endif
 }

sql/sql_class.cc

@@ -2586,8 +2586,6 @@ Statement::Statement(LEX *lex_arg, MEM_ROOT *mem_root_arg,
   db(NULL),
   db_length(0)
 {
-  query_string.length= 0;
-  query_string.str= NULL;
   name.str= NULL;
 }
 
@@ -2626,15 +2624,6 @@ void Statement::restore_backup_statement(Statement *stmt, Statement *backup)
 }
 
 
-/** Assign a new value to thd->query.  */
-
-void Statement::set_query_inner(char *query_arg, uint32 query_length_arg)
-{
-  query_string.str= query_arg;
-  query_string.length= query_length_arg;
-}
-
-
 void THD::end_statement()
 {
   /* Cleanup SQL processing state to reuse this statement in next query. */
@@ -3167,7 +3156,7 @@ extern "C" struct charset_info_st *thd_charset(MYSQL_THD thd)
 */
 extern "C" char **thd_query(MYSQL_THD thd)
 {
-  return(&thd->query_string.str);
+  return (&thd->query_string.string.str);
 }
 
 /**
@@ -3178,7 +3167,7 @@ extern "C" char **thd_query(MYSQL_THD thd)
 */
 extern "C" LEX_STRING * thd_query_string (MYSQL_THD thd)
 {
-  return(&thd->query_string);
+  return(&thd->query_string.string);
 }
 
 extern "C" int thd_slave_thread(const MYSQL_THD thd)
@@ -3423,20 +3412,21 @@ void THD::set_statement(Statement *stmt)
 
 /** Assign a new value to thd->query.  */
 
-void THD::set_query(char *query_arg, uint32 query_length_arg)
+void THD::set_query(const CSET_STRING &string_arg)
 {
   mysql_mutex_lock(&LOCK_thd_data);
-  set_query_inner(query_arg, query_length_arg);
+  set_query_inner(string_arg);
   mysql_mutex_unlock(&LOCK_thd_data);
 }
 
 /** Assign a new value to thd->query and thd->query_id.  */
 
 void THD::set_query_and_id(char *query_arg, uint32 query_length_arg,
+                           CHARSET_INFO *cs,
                            query_id_t new_query_id)
 {
   mysql_mutex_lock(&LOCK_thd_data);
-  set_query_inner(query_arg, query_length_arg);
+  set_query_inner(query_arg, query_length_arg, cs);
   query_id= new_query_id;
   mysql_mutex_unlock(&LOCK_thd_data);
 }

sql/sql_class.h

@@ -109,6 +109,41 @@ extern MYSQL_PLUGIN_IMPORT const char **errmesg;
 
 extern bool volatile shutdown_in_progress;
 
+extern "C" LEX_STRING * thd_query_string (MYSQL_THD thd);
+extern "C" char **thd_query(MYSQL_THD thd);
+
+/**
+  @class CSET_STRING
+  @brief Character set armed LEX_STRING
+*/
+class CSET_STRING
+{
+private:
+  LEX_STRING string;
+  CHARSET_INFO *cs;
+public:
+  CSET_STRING() : cs(&my_charset_bin)
+  {
+    string.str= NULL;
+    string.length= 0;
+  }
+  CSET_STRING(char *str_arg, size_t length_arg, CHARSET_INFO *cs_arg) :
+  cs(cs_arg)
+  {
+    DBUG_ASSERT(cs_arg != NULL);
+    string.str= str_arg;
+    string.length= length_arg;
+  }
+
+  inline char *str() const { return string.str; }
+  inline uint32 length() const { return string.length; }
+  CHARSET_INFO *charset() const { return cs; }
+
+  friend LEX_STRING * thd_query_string (MYSQL_THD thd);
+  friend char **thd_query(MYSQL_THD thd);
+};
+
+
 #define TC_LOG_PAGE_SIZE   8192
 #define TC_LOG_MIN_SIZE    (3*TC_LOG_PAGE_SIZE)
 
@@ -722,12 +757,24 @@ public:
     This printing is needed at least in SHOW PROCESSLIST and SHOW
     ENGINE INNODB STATUS.
   */
-  LEX_STRING query_string;
+  CSET_STRING query_string;
-
-  inline char *query() { return query_string.str; }
-  inline uint32 query_length() { return query_string.length; }
-  void set_query_inner(char *query_arg, uint32 query_length_arg);
 
+  inline char *query() const { return query_string.str(); }
+  inline uint32 query_length() const { return query_string.length(); }
+  CHARSET_INFO *query_charset() const { return query_string.charset(); }
+  void set_query_inner(const CSET_STRING &string_arg)
+  {
+    query_string= string_arg;
+  }
+  void set_query_inner(char *query_arg, uint32 query_length_arg,
+                       CHARSET_INFO *cs_arg)
+  {
+    set_query_inner(CSET_STRING(query_arg, query_length_arg, cs_arg));
+  }
+  void reset_query_inner()
+  {
+    set_query_inner(CSET_STRING());
+  }
   /**
     Name of the current (default) database.
 
@@ -2676,9 +2723,20 @@ public:
     Assign a new value to thd->query and thd->query_id and mysys_var.
     Protected with LOCK_thd_data mutex.
   */
-  void set_query(char *query_arg, uint32 query_length_arg);
+  void set_query(char *query_arg, uint32 query_length_arg,
+                 CHARSET_INFO *cs_arg)
+  {
+    set_query(CSET_STRING(query_arg, query_length_arg, cs_arg));
+  }
+  void set_query(char *query_arg, uint32 query_length_arg) /*Mutex protected*/
+  {
+    set_query(CSET_STRING(query_arg, query_length_arg, charset()));
+  }
+  void set_query(const CSET_STRING &str); /* Mutex protected */
+  void reset_query()               /* Mutex protected */
+  { set_query(CSET_STRING()); }
   void set_query_and_id(char *query_arg, uint32 query_length_arg,
-                        query_id_t new_query_id);
+                        CHARSET_INFO *cs, query_id_t new_query_id);
   void set_query_id(query_id_t new_query_id);
   void set_open_tables(TABLE *open_tables_arg)
   {

sql/sql_insert.cc

@@ -2099,7 +2099,8 @@ bool delayed_get_table(THD *thd, TABLE_LIST *table_list)
       mysql_mutex_unlock(&LOCK_thread_count);
       di->thd.set_db(table_list->db, (uint) strlen(table_list->db));
       di->thd.set_query(my_strdup(table_list->table_name,
-                                  MYF(MY_WME | ME_FATALERROR)), 0);
+                                  MYF(MY_WME | ME_FATALERROR)),
+                        0, system_charset_info);
       if (di->thd.db == NULL || di->thd.query() == NULL)
       {
         /* The error is reported */

sql/sql_parse.cc

@@ -550,7 +550,7 @@ static void handle_bootstrap_impl(THD *thd)
     query= (char *) thd->memdup_w_gap(buff, length + 1,
                                       thd->db_length + 1 +
                                       QUERY_CACHE_FLAGS_SIZE);
-    thd->set_query_and_id(query, length, next_query_id());
+    thd->set_query_and_id(query, length, thd->charset(), next_query_id());
     DBUG_PRINT("query",("%-.4096s",thd->query()));
 #if defined(ENABLED_PROFILING)
     thd->profiling.start_new_query();
@@ -1065,7 +1065,8 @@ bool dispatch_command(enum enum_server_command command, THD *thd,
                         thd->security_ctx->priv_user,
                         (char *) thd->security_ctx->host_or_ip);
 
-      thd->set_query_and_id(beginning_of_next_stmt, length, next_query_id());
+      thd->set_query_and_id(beginning_of_next_stmt, length,
+                            thd->charset(), next_query_id());
       /*
         Count each statement from the client.
       */
@@ -1390,7 +1391,7 @@ bool dispatch_command(enum enum_server_command command, THD *thd,
   log_slow_statement(thd);
 
   thd_proc_info(thd, "cleaning up");
-  thd->set_query(NULL, 0);
+  thd->reset_query();
   thd->command=COM_SLEEP;
   dec_thread_running();
   thd_proc_info(thd, 0);
@@ -5494,7 +5495,8 @@ void mysql_parse(THD *thd, char *rawbuf, uint length,
           if (found_semicolon && (ulong) (found_semicolon - thd->query()))
             thd->set_query_inner(thd->query(),
                                  (uint32) (found_semicolon -
-                                           thd->query() - 1));
+                                           thd->query() - 1),
+                                 thd->charset());
           /* Actually execute the query */
           if (found_semicolon)
           {

sql/sql_prepare.cc

@@ -3742,7 +3742,7 @@ bool Prepared_statement::execute(String *expanded_query, bool open_cursor)
     to point at it even after we restore from backup. This is ok, as
     expanded query was allocated in thd->mem_root.
   */
-  stmt_backup.set_query_inner(thd->query(), thd->query_length());
+  stmt_backup.set_query_inner(thd->query_string);
 
   /*
     At first execution of prepared statement we may perform logical

sql/sql_show.cc

@@ -1727,7 +1727,7 @@ public:
   time_t start_time;
   uint   command;
   const char *user,*host,*db,*proc_info,*state_info;
-  char *query;
+  CSET_STRING query_string;
 };
 
 #ifdef HAVE_EXPLICIT_TEMPLATE_INSTANTIATION
@@ -1824,12 +1824,14 @@ void mysqld_list_processes(THD *thd,const char *user, bool verbose)
         if (mysys_var)
           mysql_mutex_unlock(&mysys_var->mutex);
 
-        thd_info->query=0;
         /* Lock THD mutex that protects its data when looking at it. */
         if (tmp->query())
         {
           uint length= min(max_query_length, tmp->query_length());
-          thd_info->query= (char*) thd->strmake(tmp->query(),length);
+          char *q= thd->strmake(tmp->query(),length);
+          /* Safety: in case strmake failed, we set length to 0. */
+          thd_info->query_string=
+            CSET_STRING(q, q ? length : 0, tmp->query_charset());
         }
         mysql_mutex_unlock(&tmp->LOCK_thd_data);
         thd_info->start_time= tmp->start_time;
@@ -1857,7 +1859,8 @@ void mysqld_list_processes(THD *thd,const char *user, bool verbose)
     else
       protocol->store_null();
     protocol->store(thd_info->state_info, system_charset_info);
-    protocol->store(thd_info->query, system_charset_info);
+    protocol->store(thd_info->query_string.str(),
+                    thd_info->query_string.charset());
     if (protocol->write())
       break; /* purecov: inspected */
   }

storage/myisam/ha_myisam.cc

@@ -1499,8 +1499,6 @@ bool ha_myisam::check_and_repair(THD *thd)
 {
   int error=0;
   int marked_crashed;
-  char *old_query;
-  uint old_query_length;
   HA_CHECK_OPT check_opt;
   DBUG_ENTER("ha_myisam::check_and_repair");
 
@@ -1511,10 +1509,9 @@ bool ha_myisam::check_and_repair(THD *thd)
     check_opt.flags|=T_QUICK;
   sql_print_warning("Checking table:   '%s'",table->s->path.str);
 
-  old_query= thd->query();
+  const CSET_STRING query_backup= thd->query_string;
-  old_query_length= thd->query_length();
   thd->set_query(table->s->table_name.str,
-                 (uint) table->s->table_name.length);
+                 (uint) table->s->table_name.length, system_charset_info);
 
   if ((marked_crashed= mi_is_crashed(file)) || check(thd, &check_opt))
   {
@@ -1527,7 +1524,7 @@ bool ha_myisam::check_and_repair(THD *thd)
     if (repair(thd, &check_opt))
       error=1;
   }
-  thd->set_query(old_query, old_query_length);
+  thd->set_query(query_backup);
   DBUG_RETURN(error);
 }