MDEV-28077 'Wrong create options' error with 'big_tables' enabled

The cause of the bug is overflow of uint16 KEY_PART_INFO::length and/or
uint16 KEY_PART_INFO::store_length. The solution is to increase the size
of those variables to the 'uint' type (which is 32-bit long)

mysql-test/r/select.result

@@ -5575,4 +5575,23 @@ SET sql_buffer_result=1;
 SELECT grp,GROUP_CONCAT(c ORDER BY 2) FROM t1 GROUP BY grp;
 grp	GROUP_CONCAT(c ORDER BY 2)
 DROP TABLE t1;
+#
+# Bug MDEV-28077 "Wrong create options" with "big_tables" option enabled
+#
+CREATE TABLE t1(a VARCHAR(16383) CHARACTER SET UTF32, KEY k(a));
+Warnings:
+Note	1071	Specified key was too long; max key length is 1000 bytes
+INSERT INTO t1 VALUES ('abc'), ('def'), ('FFF'), ('abc'), ('FFF');
+SET SESSION big_tables=ON;
+SELECT DISTINCT COUNT(DISTINCT a) FROM t1;
+COUNT(DISTINCT a)
+3
+PREPARE stmt FROM 'SELECT DISTINCT COUNT(DISTINCT a) FROM t1';
+EXECUTE stmt;
+COUNT(DISTINCT a)
+3
+EXECUTE stmt;
+COUNT(DISTINCT a)
+3
+DROP TABLE t1;
 End of 10.0 tests

mysql-test/r/select_jcl6.result

@@ -5586,6 +5586,25 @@ SET sql_buffer_result=1;
 SELECT grp,GROUP_CONCAT(c ORDER BY 2) FROM t1 GROUP BY grp;
 grp	GROUP_CONCAT(c ORDER BY 2)
 DROP TABLE t1;
+#
+# Bug MDEV-28077 "Wrong create options" with "big_tables" option enabled
+#
+CREATE TABLE t1(a VARCHAR(16383) CHARACTER SET UTF32, KEY k(a));
+Warnings:
+Note	1071	Specified key was too long; max key length is 1000 bytes
+INSERT INTO t1 VALUES ('abc'), ('def'), ('FFF'), ('abc'), ('FFF');
+SET SESSION big_tables=ON;
+SELECT DISTINCT COUNT(DISTINCT a) FROM t1;
+COUNT(DISTINCT a)
+3
+PREPARE stmt FROM 'SELECT DISTINCT COUNT(DISTINCT a) FROM t1';
+EXECUTE stmt;
+COUNT(DISTINCT a)
+3
+EXECUTE stmt;
+COUNT(DISTINCT a)
+3
+DROP TABLE t1;
 End of 10.0 tests
 set join_cache_level=default;
 set @@optimizer_switch=@save_optimizer_switch_jcl6;

mysql-test/r/select_pkeycache.result

@@ -5575,4 +5575,23 @@ SET sql_buffer_result=1;
 SELECT grp,GROUP_CONCAT(c ORDER BY 2) FROM t1 GROUP BY grp;
 grp	GROUP_CONCAT(c ORDER BY 2)
 DROP TABLE t1;
+#
+# Bug MDEV-28077 "Wrong create options" with "big_tables" option enabled
+#
+CREATE TABLE t1(a VARCHAR(16383) CHARACTER SET UTF32, KEY k(a));
+Warnings:
+Note	1071	Specified key was too long; max key length is 1000 bytes
+INSERT INTO t1 VALUES ('abc'), ('def'), ('FFF'), ('abc'), ('FFF');
+SET SESSION big_tables=ON;
+SELECT DISTINCT COUNT(DISTINCT a) FROM t1;
+COUNT(DISTINCT a)
+3
+PREPARE stmt FROM 'SELECT DISTINCT COUNT(DISTINCT a) FROM t1';
+EXECUTE stmt;
+COUNT(DISTINCT a)
+3
+EXECUTE stmt;
+COUNT(DISTINCT a)
+3
+DROP TABLE t1;
 End of 10.0 tests

mysql-test/t/select.test

@@ -4698,4 +4698,22 @@ SET sql_buffer_result=1;
 SELECT grp,GROUP_CONCAT(c ORDER BY 2) FROM t1 GROUP BY grp;
 DROP TABLE t1;
 
+--echo #
+--echo # Bug MDEV-28077 "Wrong create options" with "big_tables" option enabled
+--echo #
+CREATE TABLE t1(a VARCHAR(16383) CHARACTER SET UTF32, KEY k(a));
+INSERT INTO t1 VALUES ('abc'), ('def'), ('FFF'), ('abc'), ('FFF');
+
+# big_tables are deprecated after some version
+--disable_warnings
+SET SESSION big_tables=ON;
+SELECT DISTINCT COUNT(DISTINCT a) FROM t1;
+
+PREPARE stmt FROM 'SELECT DISTINCT COUNT(DISTINCT a) FROM t1';
+EXECUTE stmt;
+EXECUTE stmt;
+
+--enable_warnings
+DROP TABLE t1;
+
 --echo End of 10.0 tests

sql/sql_select.cc

@@ -12419,6 +12419,7 @@ void JOIN::cleanup(bool full)
           if (curr_tab->aggr)
           {
             free_tmp_table(thd, curr_tab->table);
+            curr_tab->table= NULL;
             delete curr_tab->tmp_table_param;
             curr_tab->tmp_table_param= NULL;
             curr_tab->aggr= NULL;

sql/structs.h

@@ -71,14 +71,14 @@ typedef struct st_key_part_info {	/* Info about a key part */
   uint  offset;                         /* Offset in record (from 0) */
   uint  null_offset;                    /* Offset to null_bit in record */
   /* Length of key part in bytes, excluding NULL flag and length bytes */
-  uint16 length;
+  uint length;
   /* 
     Number of bytes required to store the keypart value. This may be
     different from the "length" field as it also counts
      - possible NULL-flag byte (see HA_KEY_NULL_LENGTH)
      - possible HA_KEY_BLOB_LENGTH bytes needed to store actual value length.
   */
-  uint16 store_length;
+  uint store_length;
   uint16 key_type;
   uint16 fieldnr;                       /* Fieldnr begins counting from 1 */
   uint16 key_part_flag;                 /* 0 or HA_REVERSE_SORT */