MDEV-28489 CONNECT used incorrect CHAR length

CONNECT engine was using dividing UTF8 columns by 3 to get the length,
but in reality it did need the byte length.

This fixes MDEV-26722 too.

storage/connect/ha_connect.cc

@@ -1618,14 +1618,9 @@ void *ha_connect::GetColumnOption(PGLOBAL g, void *field, PCOLINFO pcf)
   pcf->Scale= 0;
   pcf->Opt= (fop) ? (int)fop->opt : 0;
 
-	if (fp->field_length >= 0) {
+	if (fp->field_length >= 0)
 		pcf->Length= fp->field_length;
-
-		// length is bytes for Connect, not characters
-		if (!strnicmp(chset, "utf8", 4))
-			pcf->Length /= 3;
-
-	} else
+	else
 		pcf->Length= 256;            // BLOB?
 
   pcf->Precision= pcf->Length;

storage/connect/mysql-test/connect/r/mysql.result

@@ -326,5 +326,43 @@ id
 DROP TABLE t1;
 DROP TABLE t2;
 #
+# MDEV-28489 / MDEV-26722 UTF8 bytes calculated incorrectly
+#
+CREATE TABLE t1 (name varchar(20)) CHARSET=utf8;
+INSERT INTO t1 (name) VALUES ('Иванова'), ('Ivanova');
+CREATE TABLE t2 (name varchar(1)) ENGINE=CONNECT TABLE_TYPE=MYSQL DBNAME='test' TABNAME='t1' OPTION_LIST='host=localhost,user=root,port=PORT' CHARSET=utf8;
+SELECT hex(name) from t1;
+hex(name)
+C390CB9CC390C2B2C390C2B0C390C2BDC390C2BEC390C2B2C390C2B0
+4976616E6F7661
+SELECT hex(name) from t2;
+hex(name)
+C390
+49
+Warnings:
+Warning	1105	Out of range value for column name at row 1
+Warning	1265	Data truncated for column 'name' at row 1
+Warning	1105	Out of range value �? for column 'name' at row 1
+Warning	1105	Out of range value for column name at row 2
+Warning	1265	Data truncated for column 'name' at row 2
+Warning	1105	Out of range value Iva for column 'name' at row 2
+DROP TABLE t2;
+DROP TABLE t1;
+CREATE TABLE t1 (col char(5)) CHARSET=utf8;
+INSERT INTO t1 (col) VALUES ('glace'), ('glacé');
+Warnings:
+Warning	1406	Data too long for column 'col' at row 2
+CREATE TABLE t2 ENGINE=CONNECT TABLE_TYPE=MYSQL DBNAME='test' TABNAME='t1' OPTION_LIST='host=localhost,user=root,port=PORT' CHARSET=utf8;
+SELECT hex(col) from t1;
+hex(col)
+676C616365
+676C6163C383
+SELECT hex(col) from t2;
+hex(col)
+676C616365
+676C6163C383
+DROP TABLE t2;
+DROP TABLE t1;
+#
 # End of 10.3 tests
 #

storage/connect/mysql-test/connect/t/mysql.test

@@ -503,6 +503,36 @@ SELECT `id` FROM t2 WHERE t2.`spaced col` = 'C-003';
 DROP TABLE t1;
 DROP TABLE t2;
 
+--echo #
+--echo # MDEV-28489 / MDEV-26722 UTF8 bytes calculated incorrectly
+--echo #
+
+CREATE TABLE t1 (name varchar(20)) CHARSET=utf8;
+INSERT INTO t1 (name) VALUES ('Иванова'), ('Ivanova');
+
+--replace_result $PORT PORT
+--eval CREATE TABLE t2 (name varchar(1)) ENGINE=CONNECT TABLE_TYPE=MYSQL DBNAME='test' TABNAME='t1' OPTION_LIST='host=localhost,user=root,port=$PORT' CHARSET=utf8
+
+SELECT hex(name) from t1;
+# This will warn as we are truncating data
+SELECT hex(name) from t2;
+
+DROP TABLE t2;
+DROP TABLE t1;
+
+CREATE TABLE t1 (col char(5)) CHARSET=utf8;
+INSERT INTO t1 (col) VALUES ('glace'), ('glacé');
+
+--replace_result $PORT PORT
+--eval CREATE TABLE t2 ENGINE=CONNECT TABLE_TYPE=MYSQL DBNAME='test' TABNAME='t1' OPTION_LIST='host=localhost,user=root,port=$PORT' CHARSET=utf8
+
+SELECT hex(col) from t1;
+SELECT hex(col) from t2;
+
+DROP TABLE t2;
+DROP TABLE t1;
+
+
 --echo #
 --echo # End of 10.3 tests
 --echo #