test that the vector index size is zero after TRUNCATE in MyISAM

mysql-test/main/vector,myisam.rdiff

+--- a/mysql-test/main/vector.result
++++ b/mysql-test/main/vector.result
+@@ -305,7 +305,29 @@ db.opt
+ create table t1 (id int auto_increment primary key, v blob not null, vector index (v));
+ truncate table t1;
+ insert t1 (v) values (x'e360d63ebe554f3fcdbc523f4522193f5236083d');
++
++MyISAM file:         datadir/test/t1#i#01
++Record format:       Packed
++Character set:       latin1_swedish_ci (8)
++Data records:                    1  Deleted blocks:                 0
++Recordlength:                   30
++
++table description:
++Key Start Len Index   Type
++1   3     6   unique  varbin NULL          
++2   2     1   multip. int8                 
+ truncate table t1;
++
++MyISAM file:         datadir/test/t1#i#01
++Record format:       Packed
++Character set:       latin1_swedish_ci (8)
++Data records:                    0  Deleted blocks:                 0
++Recordlength:                   30
++
++table description:
++Key Start Len Index   Type
++1   3     6   unique  varbin NULL          
++2   2     1   multip. int8                 
+ select * from t1;
+ id	v
+ show create table t1;

mysql-test/main/vector.test

@@ -105,7 +105,15 @@ list_files $datadir/test;
 create table t1 (id int auto_increment primary key, v blob not null, vector index (v));
 truncate table t1;
 insert t1 (v) values (x'e360d63ebe554f3fcdbc523f4522193f5236083d');
+if ($MTR_COMBINATION_MYISAM) {
+--replace_result $datadir datadir
+--exec $MYISAMCHK -d $datadir/test/t1#i#01
+}
 truncate table t1;
+if ($MTR_COMBINATION_MYISAM) {
+--replace_result $datadir datadir
+--exec $MYISAMCHK -d $datadir/test/t1#i#01
+}
 select * from t1;
 replace_result InnoDB MyISAM;
 show create table t1;