From 3daf89ced99b41ad6144cd1d4236959e641f5592 Mon Sep 17 00:00:00 2001
From: Nirbhay Choubey <nirbhay@mariadb.com>
Date: Wed, 5 Oct 2016 04:24:07 -0400
Subject: [PATCH] MDEV-10957: Assertion failure when dropping a myisam table
 with wsrep_replicate_myisam enabled

Internal updates to system statistical tables could wrongly
trigger an additional total-order replication if wsrep_repli
-cate_myisam is enabled.
Fixed by adding a check to skip total-order replication for
stat tables.

Test: galera.galera_var_replicate_myisam_on
---
 sql/sql_base.cc       |  1 +
 sql/sql_statistics.cc | 18 ++++++++++++++++++
 sql/sql_statistics.h  |  1 +
 3 files changed, 20 insertions(+)

diff --git a/sql/sql_base.cc b/sql/sql_base.cc
index b4a3cc27d2c..f04bece86d2 100644
--- a/sql/sql_base.cc
+++ b/sql/sql_base.cc
@@ -4736,6 +4736,7 @@ restart:
       (*start)                                 &&
       (*start)->table                          &&
       (*start)->table->file->ht == myisam_hton &&
+      !is_stat_table((*start)->db, (*start)->alias) &&
       sqlcom_can_generate_row_events(thd)      &&
       thd->get_command() != COM_STMT_PREPARE)
   {
diff --git a/sql/sql_statistics.cc b/sql/sql_statistics.cc
index 311263c39b1..27bc0fb4cd3 100644
--- a/sql/sql_statistics.cc
+++ b/sql/sql_statistics.cc
@@ -3840,3 +3840,21 @@ double Histogram::point_selectivity(double pos, double avg_sel)
   return sel;
 }
 
+/*
+  Check whether the table is one of the persistent statistical tables.
+*/
+bool is_stat_table(const char *db, const char *table)
+{
+  DBUG_ASSERT(db && table);
+
+  if (!memcmp(db, stat_tables_db_name.str, stat_tables_db_name.length))
+  {
+    for (uint i= 0; i < STATISTICS_TABLES; i ++)
+    {
+      if (!memcmp(table, stat_table_name[i].str, stat_table_name[i].length))
+        return true;
+    }
+  }
+  return false;
+}
+
diff --git a/sql/sql_statistics.h b/sql/sql_statistics.h
index 8e5f8107849..20b2eb66449 100644
--- a/sql/sql_statistics.h
+++ b/sql/sql_statistics.h
@@ -107,6 +107,7 @@ double get_column_range_cardinality(Field *field,
                                     key_range *min_endp,
                                     key_range *max_endp,
                                     uint range_flag);
+bool is_stat_table(const char *db, const char *table);
 
 class Histogram
 {