MDEV-16757 Memory leak after adding manually min/max statistical data

           for blob column

ANALYZE TABLE <table> does not collect statistical data on min/max values
for BLOB columns of <table>. However these values can be added into
mysql.column_stats manually by executing proper statements.
Unfortunately this led to a memory leak because the memory allocated
for these values was never freed.
This patch provides the server with a function to free memory allocated
for min/max statistical values of BLOB types.

1 files changed, 2 insertions, 0 deletions

diff --git a/sql/table_cache.cc b/sql/table_cache.cc
index bdb7914c32b..a31068c9bc3 100644
--- a/sql/table_cache.cc
+++ b/sql/table_cache.cc
@@ -52,6 +52,7 @@
 #include "hash.h"
 #include "table.h"
 #include "sql_base.h"
+#include "sql_statistics.h"
 
 /** Configuration. */
 ulong tdc_size; /**< Table definition cache threshold for LRU eviction. */
@@ -869,6 +870,7 @@ void tdc_release_share(TABLE_SHARE *share)
   mysql_mutex_lock(&share->tdc.LOCK_table_share);
   if (share->tdc.flushed)
   {
+    delete_stat_values_for_table_share(share);
     mysql_mutex_unlock(&share->tdc.LOCK_table_share);
     mysql_mutex_unlock(&LOCK_unused_shares);
     tdc_delete_share_from_hash(share);