From 8feb78ef53d254539caa0ede374acf2d4db13d2b Mon Sep 17 00:00:00 2001
From: Sergei Golubchik <serg@mariadb.org>
Date: Sat, 11 May 2019 16:56:41 +0200
Subject: [PATCH] cleanup: replace a magic constant with a define

---
 sql/sql_truncate.cc | 2 +-
 sql/table.h         | 2 ++
 sql/table_cache.cc  | 2 +-
 3 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/sql/sql_truncate.cc b/sql/sql_truncate.cc
index c0dee66c317..c89ca92bcb1 100644
--- a/sql/sql_truncate.cc
+++ b/sql/sql_truncate.cc
@@ -319,7 +319,7 @@ bool Sql_cmd_truncate_table::lock_table(THD *thd, TABLE_LIST *table_ref,
     TABLE_SHARE *share= tdc_acquire_share(thd, table_ref, GTS_TABLE | GTS_VIEW);
     if (share == NULL)
       DBUG_RETURN(TRUE);
-    DBUG_ASSERT(share != (TABLE_SHARE*)1);
+    DBUG_ASSERT(share != UNUSABLE_TABLE_SHARE);
 
     versioned= share->versioned;
     sequence= share->table_type == TABLE_TYPE_SEQUENCE;
diff --git a/sql/table.h b/sql/table.h
index 865824bf36f..3b965f525d3 100644
--- a/sql/table.h
+++ b/sql/table.h
@@ -1025,6 +1025,8 @@ struct TABLE_SHARE
   void set_overlapped_keys();
 };
 
+/* not NULL, but cannot be dereferenced */
+#define UNUSABLE_TABLE_SHARE ((TABLE_SHARE*)1)
 
 /**
    Class is used as a BLOB field value storage for
diff --git a/sql/table_cache.cc b/sql/table_cache.cc
index 7a555d53558..5631232e066 100644
--- a/sql/table_cache.cc
+++ b/sql/table_cache.cc
@@ -945,7 +945,7 @@ end:
       table existed?
       Let's return an invalid pointer here to catch dereferencing attempts.
     */
-    share= (TABLE_SHARE*) 1;
+    share= UNUSABLE_TABLE_SHARE;
   }
   DBUG_RETURN(share);