Bug #38001000: MySQL #14: an assertion failure

Improved the check for subqueries in INSTALL COMPONENT SET

Change-Id: I12a7ccad21904f18eead174edf6d3164134d9645

Author: gkodinov

mysql-test/r/component_set.result

@@ -32,7 +32,7 @@ UNINSTALL COMPONENT "file://component_validate_password";
 CREATE TABLE t1(a INT);
 INSERT INTO t1 VALUES (1),(2);
 INSTALL COMPONENT "file://component_validate_password" SET length = (SELECT a FROM t1);
-ERROR HY000: You may only use constant expressions with SET
+ERROR 42000: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '(SELECT a FROM t1)' at line 1
 DROP TABLE t1;
 SET @gizmo = 32;
 INSTALL COMPONENT "file://component_validate_password" SET length = @gizmo;

mysql-test/t/component_set.test

@@ -44,7 +44,7 @@ UNINSTALL COMPONENT "file://component_validate_password";
 
 CREATE TABLE t1(a INT);
 INSERT INTO t1 VALUES (1),(2);
---error ER_SET_CONSTANTS_ONLY
+--error ER_PARSE_ERROR
 INSTALL COMPONENT "file://component_validate_password" SET length = (SELECT a FROM t1);
 DROP TABLE t1;
 

sql/parse_tree_nodes.cc

@@ -4843,7 +4843,9 @@ PT_install_component::PT_install_component(
 
 Sql_cmd *PT_install_component::make_cmd(THD *thd) {
   thd->lex->sql_command = SQLCOM_INSTALL_COMPONENT;
-
+  thd->lex->expr_allows_subquery = false;
+  auto f =
+      create_scope_guard([thd]() { thd->lex->expr_allows_subquery = true; });
   if (!m_set_elements->is_empty()) {
     Parse_context pc(thd, thd->lex->current_query_block());
     for (auto &elt : *m_set_elements) {