MDEV-36034 KILL or timeout inside derived table optimization causes an assert

If the call to mysql_handle_single_derived(..., DT_OPTIMIZE) in
JOIN::optimize_inner() returns 1, then JOIN::optimize_inner() will
also return 1 but will not set JOIN::error.

Sql_cmd_dml::execute_inner() would note this error but will return
0 (JOIN::error) to its caller, Sql_cmd_update|delete::execute_inner.
The caller will try to print the query plan and hit an assertion due
to query plan not being present.

Queries affected by the this bug involve explain format=json with a
DML statement containing a derived table and some manner of execution
abortion, a timeout or kill.

Fixed by setting JOIN::error.

Approved by: Sergei Petrunia (sergey@mariadb.com)

Author: mariadb-RexJohnston

mysql-test/main/kill.result

@@ -185,3 +185,22 @@ DROP TABLE t1, t2;
 #
 kill query id user 'foo';
 ERROR 42S22: Unknown column 'user' in 'KILL'
+#
+# MDEV-36034 KILL or timeout inside derived table optimization causes an assert
+#
+CREATE TABLE t10(c int primary key, c2 int) engine=innodb;
+CREATE TABLE t20(c INT) engine=innodb;
+connect con1, localhost, root;
+connection default;
+set debug_sync='before_get_quick_record_count SIGNAL target_ready WAIT_FOR target_continue';
+explain format=json
+update t20,(SELECT * FROM t10)t (a, c)
+set t20.c=t.c+10 where t20.c = t.c and t.a >= 3;
+connection con1;
+set debug_sync='now WAIT_FOR target_ready';
+kill query $id;
+connection default;
+ERROR 70100: Query execution was interrupted
+disconnect con1;
+drop table t10, t20;
+set debug_sync='reset';

mysql-test/main/kill.test

@@ -9,6 +9,8 @@
 
 -- source include/count_sessions.inc
 -- source include/not_embedded.inc
+-- source include/have_innodb.inc
+-- source include/have_debug_sync.inc
 
 --disable_service_connection
 
@@ -320,3 +322,36 @@ DROP TABLE t1, t2;
 --error ER_BAD_FIELD_ERROR
 kill query id user 'foo';
 --enable_service_connection
+
+
+--echo #
+--echo # MDEV-36034 KILL or timeout inside derived table optimization causes an assert
+--echo #
+
+CREATE TABLE t10(c int primary key, c2 int) engine=innodb;
+CREATE TABLE t20(c INT) engine=innodb;
+
+connect con1, localhost, root;
+connection default;
+
+set debug_sync='before_get_quick_record_count SIGNAL target_ready WAIT_FOR target_continue';
+let $id=`select connection_id()`;
+
+send
+explain format=json
+update t20,(SELECT * FROM t10)t (a, c)
+  set t20.c=t.c+10 where t20.c = t.c and t.a >= 3;
+
+connection con1;
+set debug_sync='now WAIT_FOR target_ready';
+evalp kill query $id;
+
+connection default;
+--error ER_QUERY_INTERRUPTED
+reap;
+
+disconnect con1;
+
+drop table t10, t20;
+
+set debug_sync='reset';

sql/sql_select.cc

@@ -2542,7 +2542,10 @@ JOIN::optimize_inner()
 	    DBUG_RETURN(1);
         }
 	if (mysql_handle_single_derived(thd->lex, tbl, DT_OPTIMIZE))
+        {
+          error= 1;
 	  DBUG_RETURN(1);
+        }
       }
     }
   }
@@ -5436,6 +5439,9 @@ static bool get_quick_record_count(THD *thd, SQL_SELECT *select,
   uchar buff[STACK_BUFF_ALLOC];
   if (unlikely(check_stack_overrun(thd, STACK_MIN_SIZE, buff)))
     DBUG_RETURN(false);                           // Fatal error flag is set
+
+  DEBUG_SYNC(thd, "before_get_quick_record_count");
+
   if (select)
   {
     select->head=table;