MDEV-28769 Assertion `(m_ci->state & 32) || m_with_collate' failed in…

… Lex_exact_charset_opt_extended_collate::Lex_exact_charset_opt_extended_collate on SET NAMES

These system variables:
  @@character_set_client
  @@character_set_connection
  @@character_set_database
  @@character_set_filesystem
  @@character_set_results
  @@character_set_server

can now be set in numeric format only to IDs of default collations, e.g.:

SET @@character_set_xxx=9;  -- OK    (latin2_general_ci  is default)
SET @@character_set_xxx=2;  -- ERROR (latin2_czech_cs is not default)
SET @@character_set_xxx=21; -- ERROR (latin2_hungarian_ci is not default)

Before this change the server accepted IDs of non-default collations
so all three examples above worked without errors,
but this could lead to unexpected behavior in later statements.

mysql-test/suite/sys_vars/r/character_set_client_basic.result

@@ -383,10 +383,9 @@ SET @@character_set_client = 1;
 SELECT @@character_set_client;
 @@character_set_client
 big5
+# latin2_czech_cs is not a default collation
 SET @@character_set_client = 2;
-SELECT @@character_set_client;
-@@character_set_client
-latin2
+ERROR 42000: Unknown character set: '2'
 SET @@character_set_client = 3;
 SELECT @@character_set_client;
 @@character_set_client
@@ -395,20 +394,19 @@ SET @@character_set_client = 36;
 SELECT @@character_set_client;
 @@character_set_client
 cp866
+# cp1250_polish_ci is not a default collation
 SET @@character_set_client = 99;
-SELECT @@character_set_client;
-@@character_set_client
-cp1250
+ERROR 42000: Unknown character set: '99'
+# Collation ID 100 does not exist
 SET @@character_set_client = 100;
 ERROR 42000: Unknown character set: '100'
 SET @@global.character_set_client = 1;
 SELECT @@global.character_set_client;
 @@global.character_set_client
 big5
+# latin2_czech_cs is not a default collation
 SET @@global.character_set_client = 2;
-SELECT @@global.character_set_client;
-@@global.character_set_client
-latin2
+ERROR 42000: Unknown character set: '2'
 SET @@global.character_set_client = 3;
 SELECT @@global.character_set_client;
 @@global.character_set_client
@@ -417,10 +415,10 @@ SET @@global.character_set_client = 36;
 SELECT @@global.character_set_client;
 @@global.character_set_client
 cp866
+# cp1250_polish_ci is not a default collation
 SET @@global.character_set_client = 99;
-SELECT @@global.character_set_client;
-@@global.character_set_client
-cp1250
+ERROR 42000: Unknown character set: '99'
+# Collation ID 100 does not exist
 SET @@global.character_set_client = 100;
 ERROR 42000: Unknown character set: '100'
 SET @total_charset = (SELECT count(*) FROM INFORMATION_SCHEMA.CHARACTER_SETS);
@@ -497,5 +495,10 @@ SELECT @@session.character_set_client =
 WHERE VARIABLE_NAME='character_set_client') AS res;
 res
 1
+#
+# MDEV-28769 Assertion `(m_ci->state & 32) || m_with_collate' failed in Lex_exact_charset_opt_extended_collate::Lex_exact_charset_opt_extended_collate on SET NAMES
+#
+SET GLOBAL character_set_client=2;
+ERROR 42000: Unknown character set: '2'
 SET @@global.character_set_client = @global_start_value;
 SET @@session.character_set_client = @session_start_value;

mysql-test/suite/sys_vars/r/character_set_connection_basic.result

@@ -378,10 +378,9 @@ SET @@character_set_connection = 1;
 SELECT @@character_set_connection;
 @@character_set_connection
 big5
+# latin2_czech_cs is not a default collation
 SET @@character_set_connection = 2;
-SELECT @@character_set_connection;
-@@character_set_connection
-latin2
+ERROR 42000: Unknown character set: '2'
 SET @@character_set_connection = 3;
 SELECT @@character_set_connection;
 @@character_set_connection
@@ -390,20 +389,19 @@ SET @@character_set_connection = 36;
 SELECT @@character_set_connection;
 @@character_set_connection
 cp866
+# cp1250_polish_ci is not a default collation
 SET @@character_set_connection = 99;
-SELECT @@character_set_connection;
-@@character_set_connection
-cp1250
+ERROR 42000: Unknown character set: '99'
+# Collation ID 100 does not exist
 SET @@character_set_connection = 100;
 ERROR 42000: Unknown character set: '100'
 SET @@global.character_set_connection = 1;
 SELECT @@global.character_set_connection;
 @@global.character_set_connection
 big5
+# latin2_czech_cs is not a default collation
 SET @@global.character_set_connection = 2;
-SELECT @@global.character_set_connection;
-@@global.character_set_connection
-latin2
+ERROR 42000: Unknown character set: '2'
 SET @@global.character_set_connection = 3;
 SELECT @@global.character_set_connection;
 @@global.character_set_connection
@@ -412,10 +410,10 @@ SET @@global.character_set_connection = 36;
 SELECT @@global.character_set_connection;
 @@global.character_set_connection
 cp866
+# cp1250_polish_ci is not a default collation
 SET @@global.character_set_connection = 99;
-SELECT @@global.character_set_connection;
-@@global.character_set_connection
-cp1250
+ERROR 42000: Unknown character set: '99'
+# Collation ID 100 does not exist
 SET @@global.character_set_connection = 100;
 ERROR 42000: Unknown character set: '100'
 SET @total_charset = (SELECT count(*) FROM INFORMATION_SCHEMA.CHARACTER_SETS);
@@ -435,8 +433,12 @@ SET @@character_set_connection = -1;
 ERROR 42000: Unknown character set: '-1'
 SET @@character_set_connection = 'utf8 ';
 ERROR 42000: Unknown character set: 'utf8 '
+SET @@character_set_connection=cp1250;
 SET @@character_set_connection = 'l�tin2';
 ERROR 42000: Unknown character set: 'l�tin2'
+SET @@character_set_connection=cp866;
+SET @@character_set_connection = 'l�tin2';
+ERROR 42000: Unknown character set: 'l?tin2'
 SET @@character_set_connection = true;
 SELECT @@character_set_connection AS res_with_true;
 res_with_true

mysql-test/suite/sys_vars/r/character_set_database_basic.result

@@ -380,10 +380,9 @@ SET @@character_set_database = 1;
 SELECT @@character_set_database;
 @@character_set_database
 big5
+# latin2_czech_cs is not a default collation
 SET @@character_set_database = 2;
-SELECT @@character_set_database;
-@@character_set_database
-latin2
+ERROR 42000: Unknown character set: '2'
 SET @@character_set_database = 3;
 SELECT @@character_set_database;
 @@character_set_database
@@ -392,20 +391,19 @@ SET @@character_set_database = 36;
 SELECT @@character_set_database;
 @@character_set_database
 cp866
+# cp1250_polish_ci is not a default collation
 SET @@character_set_database = 99;
-SELECT @@character_set_database;
-@@character_set_database
-cp1250
+ERROR 42000: Unknown character set: '99'
+# Collation ID 100 does not exist
 SET @@character_set_database = 100;
 ERROR 42000: Unknown character set: '100'
 SET @@global.character_set_database = 1;
 SELECT @@global.character_set_database;
 @@global.character_set_database
 big5
+# latin2_czech_cs is not a default collation
 SET @@global.character_set_database = 2;
-SELECT @@global.character_set_database;
-@@global.character_set_database
-latin2
+ERROR 42000: Unknown character set: '2'
 SET @@global.character_set_database = 3;
 SELECT @@global.character_set_database;
 @@global.character_set_database
@@ -414,10 +412,10 @@ SET @@global.character_set_database = 36;
 SELECT @@global.character_set_database;
 @@global.character_set_database
 cp866
+# cp1250_polish_ci is not a default collation
 SET @@global.character_set_database = 99;
-SELECT @@global.character_set_database;
-@@global.character_set_database
-cp1250
+ERROR 42000: Unknown character set: '99'
+# Collation ID 100 does not exist
 SET @@global.character_set_database = 100;
 ERROR 42000: Unknown character set: '100'
 SET @total_charset = (SELECT count(*) FROM INFORMATION_SCHEMA.CHARACTER_SETS);

mysql-test/suite/sys_vars/r/character_set_filesystem_basic.result

@@ -379,10 +379,9 @@ SET @@character_set_filesystem = 1;
 SELECT @@character_set_filesystem;
 @@character_set_filesystem
 big5
+# latin2_czech_cs is not a default collation
 SET @@character_set_filesystem = 2;
-SELECT @@character_set_filesystem;
-@@character_set_filesystem
-latin2
+ERROR 42000: Unknown character set: '2'
 SET @@character_set_filesystem = 3;
 SELECT @@character_set_filesystem;
 @@character_set_filesystem
@@ -391,10 +390,10 @@ SET @@character_set_filesystem = 36;
 SELECT @@character_set_filesystem;
 @@character_set_filesystem
 cp866
+# cp1250_polish_ci is not a default collation
 SET @@character_set_filesystem = 99;
-SELECT @@character_set_filesystem;
-@@character_set_filesystem
-cp1250
+ERROR 42000: Unknown character set: '99'
+# Collation ID 100 does not exist
 SET @@character_set_filesystem = 100;
 ERROR 42000: Unknown character set: '100'
 SET @total_charset = (SELECT count(*) FROM INFORMATION_SCHEMA.CHARACTER_SETS);

mysql-test/suite/sys_vars/r/character_set_server_basic.result

@@ -382,10 +382,9 @@ SET @@character_set_server = 1;
 SELECT @@character_set_server;
 @@character_set_server
 big5
+# latin2_czech_cs is not a default collation
 SET @@character_set_server = 2;
-SELECT @@character_set_server;
-@@character_set_server
-latin2
+ERROR 42000: Unknown character set: '2'
 SET @@character_set_server = 3;
 SELECT @@character_set_server;
 @@character_set_server
@@ -394,28 +393,27 @@ SET @@character_set_server = 36;
 SELECT @@character_set_server;
 @@character_set_server
 cp866
+# cp1250_polish_ci is not a default collation
 SET @@character_set_server = 99;
-SELECT @@character_set_server;
-@@character_set_server
-cp1250
+ERROR 42000: Unknown character set: '99'
+# Collation ID 100 does not exist
 SET @@character_set_server = 100;
 ERROR 42000: Unknown character set: '100'
 SET @@global.character_set_server = 1;
 SELECT @@global.character_set_server;
 @@global.character_set_server
 big5
+# latin2_czech_cs is not a default collation
 SET @@global.character_set_server = 2;
-SELECT @@global.character_set_server;
-@@global.character_set_server
-latin2
+ERROR 42000: Unknown character set: '2'
 SET @@global.character_set_server = 36;
 SELECT @@global.character_set_server;
 @@global.character_set_server
 cp866
+# cp1250_polish_ci is not a default collation
 SET @@global.character_set_server = 99;
-SELECT @@global.character_set_server;
-@@global.character_set_server
-cp1250
+ERROR 42000: Unknown character set: '99'
+# Collation ID 100 does not exist
 SET @@global.character_set_server = 100;
 ERROR 42000: Unknown character set: '100'
 '#--------------------FN_DYNVARS_009_10-------------------------#'

mysql-test/suite/sys_vars/t/character_set_client_basic.test

@@ -229,33 +229,44 @@ SELECT @@global.character_set_client;
 ##############################################################
 SET @@character_set_client = 1;
 SELECT @@character_set_client;
+
+--echo # latin2_czech_cs is not a default collation
+--error ER_UNKNOWN_CHARACTER_SET
 SET @@character_set_client = 2;
-SELECT @@character_set_client;
+
 SET @@character_set_client = 3;
 SELECT @@character_set_client;
 SET @@character_set_client = 36;
 SELECT @@character_set_client;
+
+--echo # cp1250_polish_ci is not a default collation
+--error ER_UNKNOWN_CHARACTER_SET
 SET @@character_set_client = 99;
-SELECT @@character_set_client;
 
+--echo # Collation ID 100 does not exist
 --Error ER_UNKNOWN_CHARACTER_SET
 SET @@character_set_client = 100;
 
 SET @@global.character_set_client = 1;
 SELECT @@global.character_set_client;
+
+--echo # latin2_czech_cs is not a default collation
+--error ER_UNKNOWN_CHARACTER_SET
 SET @@global.character_set_client = 2;
-SELECT @@global.character_set_client;
+
 SET @@global.character_set_client = 3;
 SELECT @@global.character_set_client;
 SET @@global.character_set_client = 36;
 SELECT @@global.character_set_client;
+
+--echo # cp1250_polish_ci is not a default collation
+--error ER_UNKNOWN_CHARACTER_SET
 SET @@global.character_set_client = 99;
-SELECT @@global.character_set_client;
 
+--echo # Collation ID 100 does not exist
 --Error ER_UNKNOWN_CHARACTER_SET
 SET @@global.character_set_client = 100;
 
-
 SET @total_charset = (SELECT count(*) FROM INFORMATION_SCHEMA.CHARACTER_SETS);
 SELECT @total_charset;
 
@@ -332,6 +343,13 @@ SELECT @@session.character_set_client =
  (SELECT VARIABLE_VALUE FROM INFORMATION_SCHEMA.SESSION_VARIABLES
   WHERE VARIABLE_NAME='character_set_client') AS res;
 
+--echo #
+--echo # MDEV-28769 Assertion `(m_ci->state & 32) || m_with_collate' failed in Lex_exact_charset_opt_extended_collate::Lex_exact_charset_opt_extended_collate on SET NAMES
+--echo #
+
+--error ER_UNKNOWN_CHARACTER_SET
+SET GLOBAL character_set_client=2;
+
 ####################################
 #     Restore initial value        #
 ####################################

mysql-test/suite/sys_vars/t/character_set_connection_basic.test

@@ -155,30 +155,42 @@ SELECT @@global.character_set_connection;
 ##############################################################
 SET @@character_set_connection = 1;
 SELECT @@character_set_connection;
+
+--echo # latin2_czech_cs is not a default collation
+--error ER_UNKNOWN_CHARACTER_SET
 SET @@character_set_connection = 2;
-SELECT @@character_set_connection;
+
 SET @@character_set_connection = 3;
 SELECT @@character_set_connection;
 SET @@character_set_connection = 36;
 SELECT @@character_set_connection;
+
+--echo # cp1250_polish_ci is not a default collation
+--error ER_UNKNOWN_CHARACTER_SET
 SET @@character_set_connection = 99;
-SELECT @@character_set_connection;
 
+--echo # Collation ID 100 does not exist
 --Error ER_UNKNOWN_CHARACTER_SET
 SET @@character_set_connection = 100;
 
 
 SET @@global.character_set_connection = 1;
 SELECT @@global.character_set_connection;
+
+--echo # latin2_czech_cs is not a default collation
+--error ER_UNKNOWN_CHARACTER_SET
 SET @@global.character_set_connection = 2;
-SELECT @@global.character_set_connection;
+
 SET @@global.character_set_connection = 3;
 SELECT @@global.character_set_connection;
 SET @@global.character_set_connection = 36;
 SELECT @@global.character_set_connection;
+
+--echo # cp1250_polish_ci is not a default collation
+--error ER_UNKNOWN_CHARACTER_SET
 SET @@global.character_set_connection = 99;
-SELECT @@global.character_set_connection;
 
+--echo # Collation ID 100 does not exist
 --Error ER_UNKNOWN_CHARACTER_SET
 SET @@global.character_set_connection = 100;
 
@@ -201,6 +213,10 @@ SET @@character_set_connection = 1.1;
 SET @@character_set_connection = -1;
 --Error ER_UNKNOWN_CHARACTER_SET
 SET @@character_set_connection = 'utf8 ';
+SET @@character_set_connection=cp1250;
+--Error ER_UNKNOWN_CHARACTER_SET
+SET @@character_set_connection = 'l�tin2';
+SET @@character_set_connection=cp866;
 --Error ER_UNKNOWN_CHARACTER_SET
 SET @@character_set_connection = 'l�tin2';
 SET @@character_set_connection = true;