MDEV-17124: mariadb 10.1.34, views and prepared statements: ERROR 1615 (HY000): Prepared statement needs to be re-preparedbb-10.2-MDEV-17124

The problem is that if table definition cache (TDC) is full of real tables
which are in tables cache, view definition can not stay there so will be
removed by its own underlying tables.
In situation above old mechanism of detection matching definition in PS
and current version always require reprepare and so prevent executing
the PS.

One work around is to increase TDC, other - improve version check for
views/triggers (which is done here). Now in suspicious cases we check:
 - timestamp (ms) of the view to be sure that version really have changed;
 - time (ms) of creation of a trigger related to time (ms) of statement
   preparation.

2 files changed, 50 insertions, 5 deletions

diff --git a/mysql-test/t/ps_ddl.test b/mysql-test/t/ps_ddl.test
index 90226d379bf..fc1bd8d3752 100644
--- a/mysql-test/t/ps_ddl.test
+++ b/mysql-test/t/ps_ddl.test
@@ -250,7 +250,8 @@ drop trigger t1_bd;
 
 set @val=11;
 execute stmt using @val;
-call p_verify_reprepare_count(1);
+# No trigger in opened table => nothing to check => no reprepare
+call p_verify_reprepare_count(0);
 select @message;
 
 --echo Test 6-e: removing a relevant trigger
@@ -259,7 +260,8 @@ drop trigger t1_bi;
 
 set @val=12;
 execute stmt using @val;
-call p_verify_reprepare_count(1);
+# No trigger in opened table => nothing to check => no reprepare
+call p_verify_reprepare_count(0);
 select @message;
 set @val=13;
 execute stmt using @val;
@@ -374,7 +376,8 @@ select * from t3;
 flush table t1;
 set @var=9;
 execute stmt using @var;
-call p_verify_reprepare_count(1);
+# flush tables now do not mean reprepare
+call p_verify_reprepare_count(0);
 select * from t2;
 select * from t3;
 drop view v1;
@@ -763,7 +766,8 @@ flush tables; # empty TDC
 create view t1 as select a, 5*a as b, 6*a as c from t2;
 lock tables t1 read, t2 read;
 execute stmt;
-call p_verify_reprepare_count(1);
+# flush tables now do not mean reprepare
+call p_verify_reprepare_count(0);
 execute stmt;
 call p_verify_reprepare_count(0);
 execute stmt;
@@ -967,7 +971,8 @@ drop trigger v2_bi;
 set @message=null;
 set @var=9;
 execute stmt using @var;
-call p_verify_reprepare_count(1);
+# No trigger in opened table => nothing to check => no reprepare
+call p_verify_reprepare_count(0);
 select @message;
 create trigger v2_bi after insert on v2 for each row set @message="v2_ai";
 set @var= 10;
diff --git a/mysql-test/t/view.test b/mysql-test/t/view.test
index 6265a514783..6914c80f635 100644
--- a/mysql-test/t/view.test
+++ b/mysql-test/t/view.test
@@ -6598,5 +6598,45 @@ drop view v1;
 drop table t1;
 
 --echo #
+--echo # MDEV-17124: mariadb 10.1.34, views and prepared statements:
+--echo # ERROR 1615 (HY000): Prepared statement needs to be re-prepared
+--echo #
+
+set @tdc= @@table_definition_cache, @tc= @@table_open_cache;
+set global table_definition_cache= 400, table_open_cache= 400;
+
+create table tt (a int, primary key(a)) engine=MyISAM;
+create view v as select * from tt;
+insert into tt values(1),(2),(3),(4);
+
+prepare stmt from 'select * from tt';
+--echo #fill table definition cache
+--disable_query_log
+--disable_result_log
+create database db;
+use db;
+--let $tables=401
+while ($tables)
+{
+  --eval create table t$tables (i int) engine=MyISAM
+  --eval select * from t$tables
+  --dec $tables
+}
+
+use test;
+
+--enable_query_log
+--enable_result_log
+execute stmt;
+prepare stmt from 'select * from v';
+execute stmt;
+
+# Cleanup
+drop database db;
+drop view v;
+drop table tt;
+set global table_definition_cache= @tdc, table_open_cache= @tc;
+
+--echo #
 --echo # End of 10.2 tests
 --echo #