MDEV-40486 [fixup] Clamp max_length at MAX_FIELD_VARCHARLENGTH in Item_func_vec_fromtext::fix_length_and_dec

This allows

create table t1 (v vector(64) not null);
insert into t1 select vec_fromtext(concat('[',group_concat(1),']')) from seq_1_to_64;

which was banned in the previous fix
bb0ac43, though this also introduces
the inconsistency(?) where

create table t1 as select vec_fromtext(concat('[',group_concat(1),']')) from seq_1_to_64;

still fails ER_TRUNCATED_WRONG_VALUE

see updated tests

TODO:
- Changes in vector_utf16.result does not look right
- the following tests crashes:

CREATE TABLE t1 (v VECTOR(2));
--error ER_TOO_BIG_FIELDLENGTH
INSERT INTO t1 VALUES (VEC_FROMTEXT(CONCAT('[1.', REPEAT('0',70000), ',2]')));
DROP TABLE t1;

SELECT VEC_FROMTEXT('😀😀😀');

Author: mariadb-YuchenPei

mysql-test/main/vector2.result

@@ -160,7 +160,7 @@ drop table t;
 # MDEV-35141 Server crashes in Field_vector::report_wrong_value upon statistic collection
 #
 create table t1 (v vector(64) not null);
-insert into t1 select vec_fromtext(cast(concat('[',group_concat(1),']') as char(130))) from seq_1_to_64;
+insert into t1 select vec_fromtext(concat('[',group_concat(1),']')) from seq_1_to_64;
 analyze table t1 persistent for all;
 Table	Op	Msg_type	Msg_text
 test.t1	analyze	status	Engine-independent statistics collected
@@ -571,11 +571,11 @@ set sql_mode=@old_sql_mode;
 ## Original testcase
 CREATE TABLE t (a TEXT) AS SELECT '[1]' AS a;
 CREATE TABLE tt AS SELECT VEC_FROMTEXT(a) AS f FROM t;
-ERROR 42000: Column length too big for column 'f' (max = 16383); use BLOB or TEXT instead
+ERROR 22007: Incorrect vector value: '\x00\x00\x80?' for column `test`.`tt`.`f` at row 1
 DROP TABLE t;
 CREATE TABLE t (a LONGBLOB) AS SELECT '[1]' AS a;
 CREATE TABLE tt AS SELECT VEC_FROMTEXT(a) AS f FROM t;
-ERROR 42000: Column length too big for column 'f' (max = 16383); use BLOB or TEXT instead
+ERROR 22007: Incorrect vector value: '\x00\x00\x80?' for column `test`.`tt`.`f` at row 1
 DROP TABLE t;
 ## Another case, which would have failed with ERROR 1292
 ## without the fix
@@ -592,7 +592,7 @@ SELECT VEC_FROMTEXT(concat('[1', repeat(',1', 16382), ']')) AS f;
 DROP TABLE tt;
 CREATE TABLE tt AS
 SELECT VEC_FROMTEXT(concat('[1', repeat(',1', 16383), ']')) AS f;
-ERROR 42000: Column length too big for column 'f' (max = 16383); use BLOB or TEXT instead
+ERROR 22007: Incorrect vector value: '\x00\x00\x80?\x00\x00\x80?\x00\x00\x80?\x00\x00\x80?\x00\x00\x80?\x00\x00\x80?\x00\x00\x80?\x00\x00\x80?\x00\x00\x80?\x00\x00...' for column `test`.`tt`.`f` at row 1
 ## "Zero-dimensional" argument, no change in behaviour after fix
 SELECT VEC_FROMTEXT('[]') as f;
 f
@@ -625,9 +625,10 @@ t2	CREATE TABLE `t2` (
 DROP TABLE t1, t2;
 CREATE TABLE t3 (f VECTOR(0));
 ERROR 42000: Incorrect column specifier for column 'f'
-## Fails because concat('[',group_concat(1),']') is mediumblob
 create view v1 as select vec_fromtext(concat('[',group_concat(1),']')) from seq_1_to_64;
-ERROR 42000: Column length too big for column 'vec_fromtext(concat('[',group_concat(1),']'))' (max = 16383); use BLOB or TEXT instead
+DROP view v1;
+create table t1 as select vec_fromtext(concat('[',group_concat(1),']')) from seq_1_to_64;
+ERROR 22007: Incorrect vector value: '\x00\x00\x80?\x00\x00\x80?\x00\x00\x80?\x00\x00\x80?\x00\x00\x80?\x00\x00\x80?\x00\x00\x80?\x00\x00\x80?\x00\x00\x80?\x00\x00...' for column `test`.`t1`.`vec_fromtext(concat('[',group_concat(1),']'))` at row 65
 ## NULLs
 select vec_fromtext(NULL);
 vec_fromtext(NULL)

mysql-test/main/vector2.test

@@ -125,7 +125,7 @@ drop table t;
 --echo # MDEV-35141 Server crashes in Field_vector::report_wrong_value upon statistic collection
 --echo #
 create table t1 (v vector(64) not null);
-insert into t1 select vec_fromtext(cast(concat('[',group_concat(1),']') as char(130))) from seq_1_to_64;
+insert into t1 select vec_fromtext(concat('[',group_concat(1),']')) from seq_1_to_64;
 analyze table t1 persistent for all;
 drop table t1;
 
@@ -453,12 +453,12 @@ set sql_mode=@old_sql_mode;
 
 --echo ## Original testcase
 CREATE TABLE t (a TEXT) AS SELECT '[1]' AS a;
---error ER_TOO_BIG_FIELDLENGTH
+--error ER_TRUNCATED_WRONG_VALUE
 CREATE TABLE tt AS SELECT VEC_FROMTEXT(a) AS f FROM t;
 DROP TABLE t;
 
 CREATE TABLE t (a LONGBLOB) AS SELECT '[1]' AS a;
---error ER_TOO_BIG_FIELDLENGTH
+--error ER_TRUNCATED_WRONG_VALUE
 CREATE TABLE tt AS SELECT VEC_FROMTEXT(a) AS f FROM t;
 DROP TABLE t;
 
@@ -478,7 +478,7 @@ CREATE TABLE tt AS
   SELECT VEC_FROMTEXT(concat('[1', repeat(',1', 16382), ']')) AS f;
 DROP TABLE tt;
 
---error ER_TOO_BIG_FIELDLENGTH
+--error ER_TRUNCATED_WRONG_VALUE
 CREATE TABLE tt AS
   SELECT VEC_FROMTEXT(concat('[1', repeat(',1', 16383), ']')) AS f;
 
@@ -503,9 +503,11 @@ DROP TABLE t1, t2;
 --error ER_WRONG_FIELD_SPEC
 CREATE TABLE t3 (f VECTOR(0));
 
---echo ## Fails because concat('[',group_concat(1),']') is mediumblob
---error ER_TOO_BIG_FIELDLENGTH
 create view v1 as select vec_fromtext(concat('[',group_concat(1),']')) from seq_1_to_64;
+DROP view v1;
+
+--error ER_TRUNCATED_WRONG_VALUE
+create table t1 as select vec_fromtext(concat('[',group_concat(1),']')) from seq_1_to_64;
 
 --echo ## NULLs
 select vec_fromtext(NULL);

mysql-test/main/vector_utf16.result

@@ -196,12 +196,7 @@ bool Item_func_vec_fromtext::fix_length_and_dec(THD *thd)
   else
     maxlen= (maxlen - 1) * 2;
   fix_length_and_charset(maxlen, &my_charset_bin);
-  if (max_length > MAX_FIELD_VARCHARLENGTH)
-  {
-    my_error(ER_TOO_BIG_FIELDLENGTH, MYF(0), name.str,
-             static_cast<ulong>(MAX_FIELD_VARCHARLENGTH / sizeof(float)));
-    return true;
-  }
+  set_if_smaller(max_length, MAX_FIELD_VARCHARLENGTH);
   set_maybe_null();
   return false;
 }
@@ -215,6 +210,9 @@ String *Item_func_vec_fromtext::val_str(String *buf)
   if ((null_value= !value))
     return nullptr;
 
+  if (value->length() > max_length)
+    return nullptr;
+
   buf->length(0);
   buf->set_charset(&my_charset_bin);
   CHARSET_INFO *cs= value->charset();