MDEV-31189 Server crash or assertion failure in upon 2nd execution of PS with views and HAVING

Do not try to decide merge/materialize for derived if it was already decided
(even if it is a view).

mysql-test/main/view.result

@@ -6956,4 +6956,22 @@ create algorithm=merge view v as
 select * from t1 left join t2 on t1.a=t2.b and t1.a in (select d from t3);
 ERROR 42S22: Unknown column 'd' in 'field list'
 drop table t1,t2,t3;
+#
+# MDEV-31189: Server crash or assertion failure in upon 2nd
+# execution of PS with views and HAVING
+#
+CREATE TABLE t (f INT);
+INSERT INTO t VALUES (1),(2);
+CREATE VIEW v1 AS SELECT 1 AS a;
+CREATE VIEW v2 AS SELECT a FROM v1;
+PREPARE stmt FROM "SELECT * FROM v2 HAVING 1 IN (SELECT f FROM t)";
+EXECUTE stmt;
+a
+1
+EXECUTE stmt;
+a
+1
+DROP VIEW v1;
+DROP VIEW v2;
+DROP TABLE t;
 # End of 10.4 tests

mysql-test/main/view.test

@@ -6696,4 +6696,23 @@ create algorithm=merge view v as
 
 drop table t1,t2,t3;
 
+--echo #
+--echo # MDEV-31189: Server crash or assertion failure in upon 2nd
+--echo # execution of PS with views and HAVING
+--echo #
+
+CREATE TABLE t (f INT);
+INSERT INTO t VALUES (1),(2); # Optional, fails either way
+CREATE VIEW v1 AS SELECT 1 AS a;
+CREATE VIEW v2 AS SELECT a FROM v1;
+
+PREPARE stmt FROM "SELECT * FROM v2 HAVING 1 IN (SELECT f FROM t)";
+EXECUTE stmt;
+EXECUTE stmt;
+
+# Cleanup
+DROP VIEW v1;
+DROP VIEW v2;
+DROP TABLE t;
+
 --echo # End of 10.4 tests

sql/table.cc

@@ -9163,8 +9163,13 @@ void TABLE_LIST::wrap_into_nested_join(List<TABLE_LIST> &join_list)
 
 static inline bool derived_table_optimization_done(TABLE_LIST *table)
 {
-  return table->derived &&
-      (table->derived->is_excluded() ||
+  SELECT_LEX_UNIT *derived= (table->derived ?
+                             table->derived :
+                             (table->view ?
+                              &table->view->unit:
+                              NULL));
+  return derived &&
+      (derived->is_excluded() ||
        table->is_materialized_derived());
 }
 
@@ -9226,8 +9231,7 @@ bool TABLE_LIST::init_derived(THD *thd, bool init_view)
     set_derived();
   }
 
-  if (is_view() ||
-      !derived_table_optimization_done(this))
+  if (!derived_table_optimization_done(this))
   {
     /* A subquery might be forced to be materialized due to a side-effect. */
     if (!is_materialized_derived() && unit->can_be_merged() &&