From 707d8653c46d4f457aecfee4eacf678a2ccc87c7 Mon Sep 17 00:00:00 2001
From: Alexey Botchkov <holyfoot@askmonty.org>
Date: Wed, 24 Mar 2021 15:05:24 +0400
Subject: [PATCH] MDEV-25228 JSON_TABLE: Server crashes in
 Query_cache::unlink_table.

JSON_TABLE shojldn't be counted in the query_cache.
---
 mysql-test/main/query_cache.result | 7 +++++++
 mysql-test/main/query_cache.test   | 7 +++++++
 sql/sql_cache.cc                   | 6 ++++--
 3 files changed, 18 insertions(+), 2 deletions(-)

diff --git a/mysql-test/main/query_cache.result b/mysql-test/main/query_cache.result
index c835e25e396..020c7472694 100644
--- a/mysql-test/main/query_cache.result
+++ b/mysql-test/main/query_cache.result
@@ -2227,6 +2227,13 @@ SHOW STATUS LIKE 'Qcache_inserts';
 Variable_name	Value
 Qcache_inserts	0
 drop table t1;
+#
+# MDEV-25228 JSON_TABLE: Server crashes in Query_cache::unlink_table.
+#
+CREATE TABLE t (a INT);
+SELECT * FROM t JOIN JSON_TABLE('{}' , '$' COLUMNS(b FOR ORDINALITY)) AS jt;
+a	b
+DROP TABLE t;
 restore defaults
 SET GLOBAL query_cache_type= default;
 SET GLOBAL query_cache_size=@save_query_cache_size;
diff --git a/mysql-test/main/query_cache.test b/mysql-test/main/query_cache.test
index 0d747b97acc..66785b42c36 100644
--- a/mysql-test/main/query_cache.test
+++ b/mysql-test/main/query_cache.test
@@ -1818,6 +1818,13 @@ select * from t1, json_table(t1.a, '$' columns (f varchar(20) path '$.a')) as jt
 SHOW STATUS LIKE 'Qcache_inserts';
 drop table t1;
 
+--echo #
+--echo # MDEV-25228 JSON_TABLE: Server crashes in Query_cache::unlink_table.
+--echo #
+CREATE TABLE t (a INT);
+SELECT * FROM t JOIN JSON_TABLE('{}' , '$' COLUMNS(b FOR ORDINALITY)) AS jt;
+DROP TABLE t;
+
 --echo restore defaults
 SET GLOBAL query_cache_type= default;
 SET GLOBAL query_cache_size=@save_query_cache_size;
diff --git a/sql/sql_cache.cc b/sql/sql_cache.cc
index 80681eee44a..49f42eb95c5 100644
--- a/sql/sql_cache.cc
+++ b/sql/sql_cache.cc
@@ -4094,11 +4094,13 @@ Query_cache::process_and_count_tables(THD *thd, TABLE_LIST *tables_used,
       *tables_type|= HA_CACHE_TBL_NONTRANSACT;
       continue;
     }
-    if (tables_used->derived)
+    if (tables_used->derived || tables_used->table_function)
     {
       DBUG_PRINT("qcache", ("table: %s", tables_used->alias.str));
       table_count--;
-      DBUG_PRINT("qcache", ("derived table skipped"));
+      DBUG_PRINT("qcache", (tables_used->table_function ?
+                              "table function skipped" :
+                              "derived table skipped"));
       continue;
     }