From 053bd80d43b9ad86bef43c0d78d183714b37de51 Mon Sep 17 00:00:00 2001
From: Sergei Golubchik <serg@mariadb.org>
Date: Wed, 23 Oct 2024 20:56:12 +0200
Subject: [PATCH] MDEV-35230 ASAN errors upon reading from joined temptable
 views with vector type

fix Field_vector::get_copy_func() for the case when length_bytes differ

fix do_copy_vec() to not guess length_bytes but take it from the field
(for keys length_bytes is always 2 for any length)
---
 mysql-test/main/vector2.result | 12 ++++++++++++
 mysql-test/main/vector2.test   | 10 ++++++++++
 sql/sql_type_vector.cc         |  7 ++++---
 3 files changed, 26 insertions(+), 3 deletions(-)

diff --git a/mysql-test/main/vector2.result b/mysql-test/main/vector2.result
index 798d09dccad..ecb8d8d999b 100644
--- a/mysql-test/main/vector2.result
+++ b/mysql-test/main/vector2.result
@@ -304,3 +304,15 @@ test.t	optimize	note	Table does not support optimize, doing recreate + analyze i
 test.t	optimize	status	OK
 insert into t select * from t;
 drop table t;
+#
+# MDEV-35230 ASAN errors upon reading from joined temptable views with vector type
+#
+create table t (f vector(1));
+insert into t values (0x30303030),(0x31313131);
+create algorithm=temptable view v as select * from t;
+select v1.f from v v1 natural join v v2;
+f
+0000
+1111
+drop view v;
+drop table t;
diff --git a/mysql-test/main/vector2.test b/mysql-test/main/vector2.test
index c1c70205bb1..a566c898bef 100644
--- a/mysql-test/main/vector2.test
+++ b/mysql-test/main/vector2.test
@@ -236,3 +236,13 @@ delete from t limit 1;
 optimize table t;
 insert into t select * from t;
 drop table t;
+
+--echo #
+--echo # MDEV-35230 ASAN errors upon reading from joined temptable views with vector type
+--echo #
+create table t (f vector(1));
+insert into t values (0x30303030),(0x31313131);
+create algorithm=temptable view v as select * from t;
+select v1.f from v v1 natural join v v2;
+drop view v;
+drop table t;
diff --git a/sql/sql_type_vector.cc b/sql/sql_type_vector.cc
index 756c6ad72a9..6a5c698eb96 100644
--- a/sql/sql_type_vector.cc
+++ b/sql/sql_type_vector.cc
@@ -243,8 +243,8 @@ int Field_vector::reset()
 
 static void do_copy_vec(const Copy_field *copy)
 {
-  uint from_length_bytes= 1 + (copy->from_length > 257);
-  uint to_length_bytes= 1 + (copy->to_length > 257);
+  uint from_length_bytes= static_cast<Field_vector*>(copy->from_field)->length_bytes;
+  uint to_length_bytes=  static_cast<Field_vector*>(copy->to_field)->length_bytes;
   uint from_length= copy->from_length - from_length_bytes;
   uint to_length= copy->to_length - to_length_bytes;
   uchar *from= copy->from_ptr + from_length_bytes;
@@ -268,7 +268,8 @@ Field::Copy_func *Field_vector::get_copy_func(const Field *from) const
 {
   if (from->type_handler() != &type_handler_vector)
     return do_field_string;
-  if (field_length == from->field_length)
+  if (field_length == from->field_length &&
+      length_bytes == static_cast<const Field_vector*>(from)->length_bytes)
     return do_field_eq;
   return do_copy_vec;
 }