MDEV-16039 Crash when selecting virtual columns generated using functions with DAYNAME()

Due to collation specifics an Item tree could change while fixing. Virtual fields.

This should be done on the correct query arena, which is table->expr_arena.

mysql-test/suite/gcol/r/gcol_bugfixes.result

@@ -604,3 +604,83 @@ test	gcol_t1	sidea		NEVER	NULL
 test	gcol_t1	sideb		NEVER	NULL
 test	gcol_t1	sidec	VIRTUAL GENERATED	ALWAYS	sqrt(`sidea` * `sidea` + `sideb` * `sideb`)
 DROP TABLE gcol_t1;
+#
+# MDEV-16039 Crash when selecting virtual columns
+# generated using functions with DAYNAME()
+#
+CREATE TABLE t1 (
+suppliersenttoday INT NOT NULL,
+suppliercaptoday CHAR(10) AS (CONCAT('',DAYNAME('2018-04-26')))
+) COLLATE utf8_bin;
+INSERT INTO t1 (suppliersenttoday) VALUES (0);
+INSERT INTO t1 (suppliersenttoday) VALUES (0);
+SELECT * FROM t1;
+suppliersenttoday	suppliercaptoday
+0	Thursday
+0	Thursday
+PREPARE STMT FROM 'INSERT INTO t1 (suppliersenttoday) VALUES (1)';
+CREATE OR REPLACE TABLE t1 (
+suppliersenttoday INT NOT NULL,
+suppliercaptoday CHAR(10) AS (CONCAT('',DAYNAME('2018-04-26')))
+) COLLATE utf8_bin;
+EXECUTE STMT;
+EXECUTE STMT;
+SELECT * FROM t1;
+suppliersenttoday	suppliercaptoday
+1	Thursday
+1	Thursday
+DROP TABLE t1;
+# (duplicate) MDEV-20380 Server crash during update
+CREATE TABLE gafld (
+nuigafld INTEGER NOT NULL,
+ucrgafld VARCHAR(30) COLLATE UTF8_BIN NOT NULL
+DEFAULT SUBSTRING_INDEX(USER(),'@',1)
+);
+EXPLAIN UPDATE gafld SET nuigafld = 0 WHERE nuigafld = 10;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	gafld	ALL	NULL	NULL	NULL	NULL	1	Using where
+EXPLAIN UPDATE gafld SET nuigafld = 0 WHERE nuigafld = 10;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	gafld	ALL	NULL	NULL	NULL	NULL	1	Using where
+DROP TABLE gafld;
+# (duplicate) MDEV-17653 replace into generated columns is unstable
+# Some columns are snipped from the MDEV test and variable is changed
+CREATE TABLE t (
+c0 TIMESTAMP NOT NULL DEFAULT current_timestamp()
+ON UPDATE current_timestamp(),
+c1 DECIMAL(27,25) GENERATED ALWAYS AS (DAYOFMONTH(@timestamp)),
+c4 TIME NOT NULL,
+c8 SMALLINT(6) GENERATED ALWAYS AS
+(CONCAT_WS(CONVERT(C1 USING CP932),
+GET_FORMAT(DATETIME, 'ISO'),
+@@GLOBAL.FLUSH_TIME) <> (c4 = 1)),
+PRIMARY KEY (c4)
+) DEFAULT CHARSET=latin1;
+REPLACE INTO t SET c0 = '2018-06-03 10:31:43', c4 = '02:58:55';
+REPLACE INTO t SET c0 = '2018-06-03 10:31:44', c4 = '02:58:55';
+REPLACE INTO t SET c0 = '2018-06-03 10:31:45', c4 = '02:58:55';
+DROP TABLE t;
+# (duplicate) MDEV-17986 crash when I insert on a table
+CREATE OR REPLACE TABLE t2 (
+number BIGINT(20) NOT NULL,
+lrn BIGINT(20) NOT NULL DEFAULT 0,
+source VARCHAR(15) NOT NULL
+DEFAULT (REVERSE(SUBSTRING_INDEX(REVERSE(user()), '@', 1))),
+PRIMARY KEY (number)
+);
+REPLACE t2(number) VALUES('1');
+REPLACE t2(number) VALUES('1');
+DROP TABLE t2;
+# (duplicate) MDEV-16048 crashing with virtual columns
+SET @save_old_sql_mode= @@sql_mode;
+SET sql_mode='';
+DROP TABLE IF EXISTS t;
+Warnings:
+Note	1051	Unknown table 'test.t'
+CREATE TABLE t (
+A INT AS (UPDATEXML((@@global.date_format), 1, SUBSTRING_INDEX(1, 2, 3)))
+) ENGINE=INNODB;
+INSERT INTO t VALUES();
+INSERT IGNORE INTO t VALUES();
+DROP TABLE t;
+SET sql_mode= @save_old_sql_mode;

mysql-test/suite/gcol/t/gcol_bugfixes.test

@@ -564,3 +564,90 @@ SELECT table_schema,table_name,column_name,extra,is_generated,generation_express
 FROM information_schema.columns WHERE table_name='gcol_t1';
 
 DROP TABLE gcol_t1;
+
+--echo #
+--echo # MDEV-16039 Crash when selecting virtual columns
+--echo # generated using functions with DAYNAME()
+--echo #
+
+CREATE TABLE t1 (
+  suppliersenttoday INT NOT NULL,
+  suppliercaptoday CHAR(10) AS (CONCAT('',DAYNAME('2018-04-26')))
+) COLLATE utf8_bin;
+
+INSERT INTO t1 (suppliersenttoday) VALUES (0);
+INSERT INTO t1 (suppliersenttoday) VALUES (0);
+SELECT * FROM t1;
+
+PREPARE STMT FROM 'INSERT INTO t1 (suppliersenttoday) VALUES (1)';
+
+CREATE OR REPLACE TABLE t1 (
+  suppliersenttoday INT NOT NULL,
+  suppliercaptoday CHAR(10) AS (CONCAT('',DAYNAME('2018-04-26')))
+) COLLATE utf8_bin;
+
+EXECUTE STMT;
+EXECUTE STMT;
+SELECT * FROM t1;
+
+DROP TABLE t1;
+
+--echo # (duplicate) MDEV-20380 Server crash during update
+CREATE TABLE gafld (
+  nuigafld INTEGER NOT NULL,
+  ucrgafld VARCHAR(30) COLLATE UTF8_BIN NOT NULL
+           DEFAULT SUBSTRING_INDEX(USER(),'@',1)
+);
+EXPLAIN UPDATE gafld SET nuigafld = 0 WHERE nuigafld = 10;
+EXPLAIN UPDATE gafld SET nuigafld = 0 WHERE nuigafld = 10;
+DROP TABLE gafld;
+
+--echo # (duplicate) MDEV-17653 replace into generated columns is unstable
+--echo # Some columns are snipped from the MDEV test and variable is changed
+CREATE TABLE t (
+  c0 TIMESTAMP NOT NULL DEFAULT current_timestamp()
+                        ON UPDATE current_timestamp(),
+  c1 DECIMAL(27,25) GENERATED ALWAYS AS (DAYOFMONTH(@timestamp)),
+  c4 TIME NOT NULL,
+  c8 SMALLINT(6) GENERATED ALWAYS AS
+                 (CONCAT_WS(CONVERT(C1 USING CP932),
+                            GET_FORMAT(DATETIME, 'ISO'),
+                            @@GLOBAL.FLUSH_TIME) <> (c4 = 1)),
+  PRIMARY KEY (c4)
+) DEFAULT CHARSET=latin1;
+
+REPLACE INTO t SET c0 = '2018-06-03 10:31:43', c4 = '02:58:55';
+REPLACE INTO t SET c0 = '2018-06-03 10:31:44', c4 = '02:58:55';
+REPLACE INTO t SET c0 = '2018-06-03 10:31:45', c4 = '02:58:55';
+
+DROP TABLE t;
+
+--echo # (duplicate) MDEV-17986 crash when I insert on a table
+CREATE OR REPLACE TABLE t2 (
+  number BIGINT(20) NOT NULL,
+  lrn BIGINT(20) NOT NULL DEFAULT 0,
+  source VARCHAR(15) NOT NULL
+                    DEFAULT (REVERSE(SUBSTRING_INDEX(REVERSE(user()), '@', 1))),
+  PRIMARY KEY (number)
+);
+
+REPLACE t2(number) VALUES('1');
+REPLACE t2(number) VALUES('1');
+
+DROP TABLE t2;
+
+
+--echo # (duplicate) MDEV-16048 crashing with virtual columns
+SET @save_old_sql_mode= @@sql_mode;
+SET sql_mode='';
+
+DROP TABLE IF EXISTS t;
+CREATE TABLE t (
+  A INT AS (UPDATEXML((@@global.date_format), 1, SUBSTRING_INDEX(1, 2, 3)))
+) ENGINE=INNODB;
+INSERT INTO t VALUES();
+INSERT IGNORE INTO t VALUES();
+
+DROP TABLE t;
+SET sql_mode= @save_old_sql_mode;
+

sql/sql_base.cc

@@ -5401,6 +5401,8 @@ static bool fix_all_session_vcol_exprs(THD *thd, TABLE_LIST *tables)
     if (!table->placeholder() && t->s->vcols_need_refixing &&
          table->lock_type >= TL_WRITE_ALLOW_WRITE)
     {
+      Query_arena backup;
+      thd->set_n_backup_active_arena(t->expr_arena, &backup);
       if (table->security_ctx)
         thd->security_ctx= table->security_ctx;
 
@@ -5418,6 +5420,7 @@ static bool fix_all_session_vcol_exprs(THD *thd, TABLE_LIST *tables)
           goto err;
 
       thd->security_ctx= save_security_ctx;
+      thd->restore_active_arena(t->expr_arena, &backup);
     }
   }
   DBUG_RETURN(0);