diff --git a/mysql-test/include/not_windows.inc b/mysql-test/include/not_windows.inc
index 08373095438..035486025f2 100644
--- a/mysql-test/include/not_windows.inc
+++ b/mysql-test/include/not_windows.inc
@@ -1,4 +1,4 @@
 #
 # suite.pm will make sure that all tests including this file
-# will be skipped unless this is on Windows
+# will be skipped if run under Windows
 #
diff --git a/mysql-test/main/stat_tables_par.inc b/mysql-test/main/stat_tables_par.inc
new file mode 100644
index 00000000000..fabb7c3e042
--- /dev/null
+++ b/mysql-test/main/stat_tables_par.inc
@@ -0,0 +1,275 @@
+# Note that this test requires a fresh restart to not have problems with the
+# old status values
+
+set @save_use_stat_tables=@@use_stat_tables;
+
+set use_stat_tables='preferably';
+
+--disable_warnings
+DROP DATABASE IF EXISTS dbt3_s001;
+--enable_warnings
+
+CREATE DATABASE dbt3_s001;
+
+use dbt3_s001;
+
+set @save_optimizer_switch=@@optimizer_switch;
+set optimizer_switch='extended_keys=off';
+ 
+--disable_query_log
+--disable_result_log
+--disable_warnings
+--source include/dbt3_s001.inc
+delete from mysql.table_stats;
+delete from mysql.column_stats;
+delete from mysql.index_stats;
+ANALYZE TABLE
+customer, lineitem, nation, orders, part, partsupp, region, supplier;
+--enable_warnings
+--enable_result_log
+--enable_query_log
+
+select * from mysql.table_stats;
+select * from mysql.index_stats;
+
+
+#
+# Test for parallel memory allocation for statistical data
+# 
+#    assumes that start the code of memory allocation for stats data has this line:
+#
+#       DEBUG_SYNC(thd, "statistics_mem_alloc_start1");
+#       DEBUG_SYNC(thd, "statistics_mem_alloc_start2");
+#
+
+let $Q6=
+select round(sum(l_extendedprice*l_discount),4) as revenue
+from lineitem
+where l_shipdate >= date '1994-01-01' 
+      and l_shipdate < date '1994-01-01' + interval '1' year
+      and l_discount between 0.06 - 0.01 and 0.06 + 0.01
+      and l_quantity < 24;
+
+flush table lineitem;
+set use_stat_tables='never';
+eval $Q6;
+
+connect (con1, localhost, root,,);
+connect (con2, localhost, root,,);
+
+connection con1;
+set debug_sync='statistics_mem_alloc_start1  WAIT_FOR second_thread_started_too';
+set debug_sync='statistics_mem_alloc_start2  SIGNAL first_thread_working';
+use dbt3_s001;
+set use_stat_tables='preferably';
+--send_eval $Q6                                            
+
+connection con2;
+set debug_sync='statistics_mem_alloc_start1  SIGNAL second_thread_started_too';
+set debug_sync='statistics_mem_alloc_start2  WAIT_FOR first_thread_working';
+use dbt3_s001;
+set use_stat_tables='preferably';
+--send_eval $Q6
+
+connection con1;
+--reap
+
+connection con2;
+--reap
+
+connection default;
+set use_stat_tables='preferably';
+disconnect con1;
+disconnect con2;
+set debug_sync='RESET';
+
+#
+# Test for parallel statistics collection
+# 
+#    assumes that start of stats collection code has this line:
+#
+#       DEBUG_SYNC(thd, "statistics_collection_start1");
+#       DEBUG_SYNC(thd, "statistics_collection_start2");
+#
+
+select * from mysql.index_stats where table_name='lineitem' order by index_name;
+delete from mysql.index_stats 
+  where table_name='lineitem' and
+        index_name in ('i_l_shipdate', 'i_l_receiptdate');
+select * from mysql.index_stats where table_name='lineitem' order by index_name;
+--disable_result_log
+--disable_warnings
+analyze table lineitem persistent for columns() indexes (i_l_shipdate);
+--enable_warnings
+--enable_result_log
+select * from mysql.index_stats where table_name='lineitem' order by index_name;
+delete from mysql.index_stats 
+  where table_name='lineitem' and index_name= 'i_l_shipdate';
+select * from mysql.index_stats where table_name='lineitem' order by index_name;
+
+connect (con1, localhost, root,,);
+connect (con2, localhost, root,,);
+
+connection con1;
+set debug_sync='statistics_collection_start1  WAIT_FOR second_thread_started_too';
+set debug_sync='statistics_collection_start2  SIGNAL first_thread_working';
+use dbt3_s001;
+set use_stat_tables='preferably';
+--send analyze table lineitem persistent for columns() indexes (i_l_shipdate)
+
+connection con2;
+set debug_sync='statistics_collection_start1  SIGNAL second_thread_started_too';
+set debug_sync='statistics_collection_start2  WAIT_FOR first_thread_working';
+use dbt3_s001;
+set use_stat_tables='preferably';
+--send analyze table lineitem persistent for columns() indexes (i_l_receiptdate)
+
+connection con1;
+--disable_result_log
+--disable_warnings
+--reap
+--enable_warnings
+--enable_result_log
+
+connection con2;
+--disable_result_log
+--disable_warnings
+--reap
+--enable_warnings
+--enable_result_log
+
+connection default;
+disconnect con1;
+disconnect con2;
+set debug_sync='RESET';
+
+select * from mysql.index_stats where table_name='lineitem' order by index_name, prefix_arity;
+
+#
+# Test for parallel statistics collection and update (innodb)
+# 
+
+select * from mysql.index_stats where table_name='lineitem'
+ order by index_name, prefix_arity;
+set debug_sync='RESET';
+
+let $innodb_storage_engine= 0;
+if (`SELECT UPPER(@@default_storage_engine) = 'INNODB'`)
+{
+  let $innodb_storage_engine= 1;
+}
+
+connect (con1, localhost, root,,);
+connect (con2, localhost, root,,);
+
+connection con1;
+set debug_sync='statistics_collection_start SIGNAL parked WAIT_FOR finish';
+use dbt3_s001;
+set use_stat_tables='preferably';
+--send analyze table lineitem persistent for all
+
+connection con2;
+set debug_sync='now WAIT_FOR parked';
+use dbt3_s001;
+set use_stat_tables='never';
+if ($innodb_storage_engine)
+{
+  select * from lineitem where l_orderkey=1 and l_partkey=156;
+  delete from lineitem where l_orderkey=1 and l_partkey=156;
+  select * from lineitem where l_orderkey=1 and l_partkey=156;
+}
+set debug_sync='now SIGNAL finish';
+
+connection con1;
+--disable_result_log
+--disable_warnings
+--reap
+--enable_warnings
+--enable_result_log
+
+connection default;
+disconnect con1;
+disconnect con2;
+set debug_sync='RESET';
+
+select * from mysql.index_stats where table_name='lineitem'
+  order by index_name, prefix_arity;
+
+#
+# Bug mdev-3891: deadlock for ANALYZE and SELECT over mysql.index_stats
+# 
+
+set @save_global_use_stat_tables=@@global.use_stat_tables;
+set global use_stat_tables='preferably';
+set debug_sync='RESET';
+
+connect (con1, localhost, root,,);
+connect (con2, localhost, root,,);
+
+connection con1;
+set debug_sync='statistics_update_start SIGNAL parker WAIT_FOR go1 EXECUTE 1';
+set debug_sync='thr_multi_lock_before_thr_lock SIGNAL go2 EXECUTE 3';
+use dbt3_s001;
+--send analyze table lineitem persistent for all
+
+connection con2;
+set debug_sync='open_and_process_table WAIT_FOR parker';
+set debug_sync='statistics_read_start SIGNAL go1 WAIT_FOR go2';
+use dbt3_s001;
+--send select * from mysql.index_stats, lineitem where index_name= 'i_l_shipdate' and l_orderkey=1 and l_partkey=68 order by prefix_arity;
+
+connection con1;
+--disable_result_log
+--disable_warnings
+--reap
+--enable_warnings
+--enable_result_log
+
+connection con2;
+--disable_warnings
+--reap
+--enable_warnings
+
+connection default;
+disconnect con1;
+disconnect con2;
+set debug_sync='RESET';
+
+set global use_stat_tables=@save_global_use_stat_tables;
+
+DROP DATABASE dbt3_s001;
+
+use test;
+
+#
+# Bug mdev-4019: crash when executing in parallel ANALYZE and 
+#                SELECT * FROM information_schema.statistics
+# 
+
+set @save_global_use_stat_tables=@@global.use_stat_tables;
+set global use_stat_tables='preferably';
+set debug_sync='RESET';
+
+create table t1 (a int, b int, key(a));
+insert t1 values (1,1),(2,2);
+
+analyze table t1;
+
+SET debug_sync='after_open_table_ignore_flush WAIT_FOR go';
+send select * from information_schema.statistics where table_schema='test';
+
+connect(con1, localhost, root);
+connection con1;
+select * from t1;
+SET DEBUG_SYNC= "now SIGNAL go";
+
+connection default;
+reap;
+
+connection default;
+disconnect con1;
+set debug_sync='RESET';
+
+drop table t1;
+set global use_stat_tables=@save_global_use_stat_tables;
+set use_stat_tables=@save_use_stat_tables;
diff --git a/mysql-test/main/stat_tables_par.result b/mysql-test/main/stat_tables_par.result
index 09ee2bbf16a..33fbe079c9e 100644
--- a/mysql-test/main/stat_tables_par.result
+++ b/mysql-test/main/stat_tables_par.result
@@ -1,3 +1,4 @@
+# restart
 set @save_use_stat_tables=@@use_stat_tables;
 set use_stat_tables='preferably';
 DROP DATABASE IF EXISTS dbt3_s001;
diff --git a/mysql-test/main/stat_tables_par.test b/mysql-test/main/stat_tables_par.test
index 383ea38fed4..5bad16075d4 100644
--- a/mysql-test/main/stat_tables_par.test
+++ b/mysql-test/main/stat_tables_par.test
@@ -1,278 +1,9 @@
+# Note that this test requires a fresh restart to not have problems with the
+# old status values
+
 --source include/have_stat_tables.inc
 --source include/have_debug_sync.inc
 --source include/not_embedded.inc
+--source include/restart_mysqld.inc
 
-set @save_use_stat_tables=@@use_stat_tables;
-
-set use_stat_tables='preferably';
-
---disable_warnings
-DROP DATABASE IF EXISTS dbt3_s001;
---enable_warnings
-
-CREATE DATABASE dbt3_s001;
-
-use dbt3_s001;
-
-set @save_optimizer_switch=@@optimizer_switch;
-set optimizer_switch='extended_keys=off';
- 
---disable_query_log
---disable_result_log
---disable_warnings
---source include/dbt3_s001.inc
-delete from mysql.table_stats;
-delete from mysql.column_stats;
-delete from mysql.index_stats;
-ANALYZE TABLE
-customer, lineitem, nation, orders, part, partsupp, region, supplier;
---enable_warnings
---enable_result_log
---enable_query_log
-
-select * from mysql.table_stats;
-select * from mysql.index_stats;
-
-
-#
-# Test for parallel memory allocation for statistical data
-# 
-#    assumes that start the code of memory allocation for stats data has this line:
-#
-#       DEBUG_SYNC(thd, "statistics_mem_alloc_start1");
-#       DEBUG_SYNC(thd, "statistics_mem_alloc_start2");
-#
-
-let $Q6=
-select round(sum(l_extendedprice*l_discount),4) as revenue
-from lineitem
-where l_shipdate >= date '1994-01-01' 
-      and l_shipdate < date '1994-01-01' + interval '1' year
-      and l_discount between 0.06 - 0.01 and 0.06 + 0.01
-      and l_quantity < 24;
-
-flush table lineitem;
-set use_stat_tables='never';
-eval $Q6;
-
-connect (con1, localhost, root,,);
-connect (con2, localhost, root,,);
-
-connection con1;
-set debug_sync='statistics_mem_alloc_start1  WAIT_FOR second_thread_started_too';
-set debug_sync='statistics_mem_alloc_start2  SIGNAL first_thread_working';
-use dbt3_s001;
-set use_stat_tables='preferably';
---send_eval $Q6                                            
-
-connection con2;
-set debug_sync='statistics_mem_alloc_start1  SIGNAL second_thread_started_too';
-set debug_sync='statistics_mem_alloc_start2  WAIT_FOR first_thread_working';
-use dbt3_s001;
-set use_stat_tables='preferably';
---send_eval $Q6
-
-connection con1;
---reap
-
-connection con2;
---reap
-
-connection default;
-set use_stat_tables='preferably';
-disconnect con1;
-disconnect con2;
-set debug_sync='RESET';
-
-#
-# Test for parallel statistics collection
-# 
-#    assumes that start of stats collection code has this line:
-#
-#       DEBUG_SYNC(thd, "statistics_collection_start1");
-#       DEBUG_SYNC(thd, "statistics_collection_start2");
-#
-
-select * from mysql.index_stats where table_name='lineitem' order by index_name;
-delete from mysql.index_stats 
-  where table_name='lineitem' and
-        index_name in ('i_l_shipdate', 'i_l_receiptdate');
-select * from mysql.index_stats where table_name='lineitem' order by index_name;
---disable_result_log
---disable_warnings
-analyze table lineitem persistent for columns() indexes (i_l_shipdate);
---enable_warnings
---enable_result_log
-select * from mysql.index_stats where table_name='lineitem' order by index_name;
-delete from mysql.index_stats 
-  where table_name='lineitem' and index_name= 'i_l_shipdate';
-select * from mysql.index_stats where table_name='lineitem' order by index_name;
-
-connect (con1, localhost, root,,);
-connect (con2, localhost, root,,);
-
-connection con1;
-set debug_sync='statistics_collection_start1  WAIT_FOR second_thread_started_too';
-set debug_sync='statistics_collection_start2  SIGNAL first_thread_working';
-use dbt3_s001;
-set use_stat_tables='preferably';
---send analyze table lineitem persistent for columns() indexes (i_l_shipdate)
-
-connection con2;
-set debug_sync='statistics_collection_start1  SIGNAL second_thread_started_too';
-set debug_sync='statistics_collection_start2  WAIT_FOR first_thread_working';
-use dbt3_s001;
-set use_stat_tables='preferably';
---send analyze table lineitem persistent for columns() indexes (i_l_receiptdate)
-
-connection con1;
---disable_result_log
---disable_warnings
---reap
---enable_warnings
---enable_result_log
-
-connection con2;
---disable_result_log
---disable_warnings
---reap
---enable_warnings
---enable_result_log
-
-connection default;
-disconnect con1;
-disconnect con2;
-set debug_sync='RESET';
-
-select * from mysql.index_stats where table_name='lineitem' order by index_name, prefix_arity;
-
-#
-# Test for parallel statistics collection and update (innodb)
-# 
-
-select * from mysql.index_stats where table_name='lineitem'
- order by index_name, prefix_arity;
-set debug_sync='RESET';
-
-let $innodb_storage_engine= 0;
-if (`SELECT UPPER(@@default_storage_engine) = 'INNODB'`)
-{
-  let $innodb_storage_engine= 1;
-}
-
-connect (con1, localhost, root,,);
-connect (con2, localhost, root,,);
-
-connection con1;
-set debug_sync='statistics_collection_start SIGNAL parked WAIT_FOR finish';
-use dbt3_s001;
-set use_stat_tables='preferably';
---send analyze table lineitem persistent for all
-
-connection con2;
-set debug_sync='now WAIT_FOR parked';
-use dbt3_s001;
-set use_stat_tables='never';
-if ($innodb_storage_engine)
-{
-  select * from lineitem where l_orderkey=1 and l_partkey=156;
-  delete from lineitem where l_orderkey=1 and l_partkey=156;
-  select * from lineitem where l_orderkey=1 and l_partkey=156;
-}
-set debug_sync='now SIGNAL finish';
-
-connection con1;
---disable_result_log
---disable_warnings
---reap
---enable_warnings
---enable_result_log
-
-connection default;
-disconnect con1;
-disconnect con2;
-set debug_sync='RESET';
-
-select * from mysql.index_stats where table_name='lineitem'
-  order by index_name, prefix_arity;
-
-#
-# Bug mdev-3891: deadlock for ANALYZE and SELECT over mysql.index_stats
-# 
-
-set @save_global_use_stat_tables=@@global.use_stat_tables;
-set global use_stat_tables='preferably';
-set debug_sync='RESET';
-
-connect (con1, localhost, root,,);
-connect (con2, localhost, root,,);
-
-connection con1;
-set debug_sync='statistics_update_start SIGNAL parker WAIT_FOR go1 EXECUTE 1';
-set debug_sync='thr_multi_lock_before_thr_lock SIGNAL go2 EXECUTE 3';
-use dbt3_s001;
---send analyze table lineitem persistent for all
-
-connection con2;
-set debug_sync='open_and_process_table WAIT_FOR parker';
-set debug_sync='statistics_read_start SIGNAL go1 WAIT_FOR go2';
-use dbt3_s001;
---send select * from mysql.index_stats, lineitem where index_name= 'i_l_shipdate' and l_orderkey=1 and l_partkey=68 order by prefix_arity;
-
-connection con1;
---disable_result_log
---disable_warnings
---reap
---enable_warnings
---enable_result_log
-
-connection con2;
---disable_warnings
---reap
---enable_warnings
-
-connection default;
-disconnect con1;
-disconnect con2;
-set debug_sync='RESET';
-
-set global use_stat_tables=@save_global_use_stat_tables;
-
-DROP DATABASE dbt3_s001;
-
-use test;
-
-#
-# Bug mdev-4019: crash when executing in parallel ANALYZE and 
-#                SELECT * FROM information_schema.statistics
-# 
-
-set @save_global_use_stat_tables=@@global.use_stat_tables;
-set global use_stat_tables='preferably';
-set debug_sync='RESET';
-
-create table t1 (a int, b int, key(a));
-insert t1 values (1,1),(2,2);
-
-analyze table t1;
-
-SET debug_sync='after_open_table_ignore_flush WAIT_FOR go';
-send select * from information_schema.statistics where table_schema='test';
-
-connect(con1, localhost, root);
-connection con1;
-select * from t1;
-SET DEBUG_SYNC= "now SIGNAL go";
-
-connection default;
-reap;
-
-connection default;
-disconnect con1;
-set debug_sync='RESET';
-
-drop table t1;
-set global use_stat_tables=@save_global_use_stat_tables;
-
-
-set use_stat_tables=@save_use_stat_tables;
+--source stat_tables_par.inc
diff --git a/mysql-test/main/stat_tables_par_innodb.result b/mysql-test/main/stat_tables_par_innodb.result
index c0b8bc378b6..c33785a9436 100644
--- a/mysql-test/main/stat_tables_par_innodb.result
+++ b/mysql-test/main/stat_tables_par_innodb.result
@@ -1,3 +1,4 @@
+# restart
 SET SESSION DEFAULT_STORAGE_ENGINE='InnoDB';
 set @save_optimizer_switch_for_stat_tables_test=@@optimizer_switch;
 set optimizer_switch='extended_keys=on';
diff --git a/mysql-test/main/stat_tables_par_innodb.test b/mysql-test/main/stat_tables_par_innodb.test
index 69adeeb7dc4..79ab23dcc3f 100644
--- a/mysql-test/main/stat_tables_par_innodb.test
+++ b/mysql-test/main/stat_tables_par_innodb.test
@@ -1,11 +1,18 @@
+# Note that this test requires a fresh restart to not have problems with the
+# old status values
+
+--source include/have_stat_tables.inc
+--source include/have_debug_sync.inc
+--source include/not_embedded.inc
 --source include/have_innodb.inc
+--source include/restart_mysqld.inc
 
 SET SESSION DEFAULT_STORAGE_ENGINE='InnoDB';
 
 set @save_optimizer_switch_for_stat_tables_test=@@optimizer_switch;
 set optimizer_switch='extended_keys=on';
 
---source stat_tables_par.test
+--source stat_tables_par.inc
 
 set optimizer_switch=@save_optimizer_switch_for_stat_tables_test;
 
diff --git a/mysql-test/mysql-test-run.pl b/mysql-test/mysql-test-run.pl
index d36370c4cac..b18924b8edc 100755
--- a/mysql-test/mysql-test-run.pl
+++ b/mysql-test/mysql-test-run.pl
@@ -4779,7 +4779,9 @@ sub extract_warning_lines ($$) {
      qr/InnoDB: Table .*mysql.*innodb_table_stats.* not found./,
      qr/InnoDB: User stopword table .* does not exist./,
      qr/Dump thread [0-9]+ last sent to server [0-9]+ binlog file:pos .+/,
-     qr/Detected table cache mutex contention at instance .* waits. Additional table cache instance cannot be activated: consider raising table_open_cache_instances. Number of active instances/
+     qr/Detected table cache mutex contention at instance .* waits. Additional table cache instance cannot be activated: consider raising table_open_cache_instances. Number of active instances/,
+     qr/WSREP: Failed to guess base node address/,
+     qr/WSREP: Guessing address for incoming client/,
     );
 
   my $matched_lines= [];
diff --git a/sql/handler.h b/sql/handler.h
index 01e10d9c4c6..a8bbc731964 100644
--- a/sql/handler.h
+++ b/sql/handler.h
@@ -5050,7 +5050,7 @@ public:
      INFORMATION_SCHEMA.TABLES without ORDER BY.
   */
   void sort_desc();
-#endif
+#endif /* DBUG_OFF */
 };
 
 int ha_discover_table(THD *thd, TABLE_SHARE *share);
@@ -5059,7 +5059,7 @@ int ha_discover_table_names(THD *thd, LEX_CSTRING *db, MY_DIR *dirp,
 bool ha_table_exists(THD *thd, const LEX_CSTRING *db, const LEX_CSTRING *table_name,
                      handlerton **hton= 0, bool *is_sequence= 0);
 bool ha_check_if_updates_are_ignored(THD *thd, handlerton *hton, const char *op);
-#endif
+#endif /* MYSQL_SERVER */
 
 /* key cache */
 extern "C" int ha_init_key_cache(const char *name, KEY_CACHE *key_cache, void *);
diff --git a/sql/sql_rename.cc b/sql/sql_rename.cc
index 73d0f377dd9..8d125fbfa06 100644
--- a/sql/sql_rename.cc
+++ b/sql/sql_rename.cc
@@ -321,59 +321,57 @@ do_rename(THD *thd, TABLE_LIST *ren_table, const LEX_CSTRING *new_db,
     DBUG_RETURN(1);                     // This can't be skipped
   }
 
-  {
-    DBUG_ASSERT(!thd->locked_tables_mode);
+  DBUG_ASSERT(!thd->locked_tables_mode);
 
 #ifdef WITH_WSREP
-    if (WSREP(thd) && hton &&
-	!wsrep_should_replicate_ddl(thd, hton->db_type))
-      DBUG_RETURN(1);
+  if (WSREP(thd) && hton &&
+      !wsrep_should_replicate_ddl(thd, hton->db_type))
+    DBUG_RETURN(1);
 #endif
 
-    tdc_remove_table(thd, TDC_RT_REMOVE_ALL,
-                     ren_table->db.str, ren_table->table_name.str);
+  tdc_remove_table(thd, TDC_RT_REMOVE_ALL,
+                   ren_table->db.str, ren_table->table_name.str);
 
-    if (hton != view_pseudo_hton)
+  if (hton != view_pseudo_hton)
+  {
+    if (hton->flags & HTON_TABLE_MAY_NOT_EXIST_ON_SLAVE)
+      *force_if_exists= 1;
+
+    if (!(rc= mysql_rename_table(hton, &ren_table->db, &old_alias,
+                                 new_db, &new_alias, 0)))
     {
-      if (hton->flags & HTON_TABLE_MAY_NOT_EXIST_ON_SLAVE)
-        *force_if_exists= 1;
-
-      if (!(rc= mysql_rename_table(hton, &ren_table->db, &old_alias,
-                                   new_db, &new_alias, 0)))
+      (void) rename_table_in_stat_tables(thd, &ren_table->db,
+                                         &ren_table->table_name,
+                                         new_db, &new_alias);
+      if ((rc= Table_triggers_list::change_table_name(thd, &ren_table->db,
+                                                      &old_alias,
+                                                      &ren_table->table_name,
+                                                      new_db,
+                                                      &new_alias)))
       {
-        (void) rename_table_in_stat_tables(thd, &ren_table->db,
-                                           &ren_table->table_name,
-                                           new_db, &new_alias);
-        if ((rc= Table_triggers_list::change_table_name(thd, &ren_table->db,
-                                                        &old_alias,
-                                                        &ren_table->table_name,
-                                                        new_db,
-                                                        &new_alias)))
-        {
-          /*
-            We've succeeded in renaming table's .frm and in updating
-            corresponding handler data, but have failed to update table's
-            triggers appropriately. So let us revert operations on .frm
-            and handler's data and report about failure to rename table.
-          */
-          (void) mysql_rename_table(hton, new_db, &new_alias,
-                                    &ren_table->db, &old_alias, NO_FK_CHECKS);
-        }
+        /*
+          We've succeeded in renaming table's .frm and in updating
+          corresponding handler data, but have failed to update table's
+          triggers appropriately. So let us revert operations on .frm
+          and handler's data and report about failure to rename table.
+        */
+        (void) mysql_rename_table(hton, new_db, &new_alias,
+                                  &ren_table->db, &old_alias, NO_FK_CHECKS);
       }
     }
+  }
+  else
+  {
+    /*
+      Change of schema is not allowed
+      except of ALTER ...UPGRADE DATA DIRECTORY NAME command
+      because a view has valid internal db&table names in this case.
+    */
+    if (thd->lex->sql_command != SQLCOM_ALTER_DB_UPGRADE &&
+        cmp(&ren_table->db, new_db))
+      my_error(ER_FORBID_SCHEMA_CHANGE, MYF(0), ren_table->db.str, new_db->str);
     else
-    {
-      /* 
-         change of schema is not allowed
-         except of ALTER ...UPGRADE DATA DIRECTORY NAME command
-         because a view has valid internal db&table names in this case.
-      */
-      if (thd->lex->sql_command != SQLCOM_ALTER_DB_UPGRADE &&
-          cmp(&ren_table->db, new_db))
-        my_error(ER_FORBID_SCHEMA_CHANGE, MYF(0), ren_table->db.str, new_db->str);
-      else
-        rc= mysql_rename_view(thd, new_db, &new_alias, ren_table);
-    }
+      rc= mysql_rename_view(thd, new_db, &new_alias, ren_table);
   }
   DBUG_RETURN(rc && !skip_error ? 1 : 0);
 }
diff --git a/storage/connect/filter.cpp b/storage/connect/filter.cpp
index d776b403917..e2361ddccb4 100644
--- a/storage/connect/filter.cpp
+++ b/storage/connect/filter.cpp
@@ -1220,7 +1220,8 @@ bool FILTER::Eval(PGLOBAL g)
   int     i; // n = 0;
 //PSUBQ   subp = NULL;
   PARRAY  ap = NULL;
-  PDBUSER dup __attribute__((unused)) = PlgGetUser(g);
+
+  (void) PlgGetUser(g);
 
   if (Opc <= OP_XX)
   {
diff --git a/storage/connect/ha_connect.cc b/storage/connect/ha_connect.cc
index 07e2173e155..489155a39a2 100644
--- a/storage/connect/ha_connect.cc
+++ b/storage/connect/ha_connect.cc
@@ -173,9 +173,9 @@ extern "C" {
        char version[]= "Version 1.07.0001 November 12, 2019";
 #if defined(__WIN__)
        char compver[]= "Version 1.07.0001 " __DATE__ " "  __TIME__;
-       char slash= '\\';
+       static char slash= '\\';
 #else   // !__WIN__
-       char slash= '/';
+       static char slash= '/';
 #endif  // !__WIN__
 } // extern "C"
 
diff --git a/storage/connect/jdbconn.cpp b/storage/connect/jdbconn.cpp
index cea4d0a5b30..f02807fa206 100644
--- a/storage/connect/jdbconn.cpp
+++ b/storage/connect/jdbconn.cpp
@@ -766,7 +766,6 @@ void JDBConn::AddJars(PSTRG jpop, char sep)
 /***********************************************************************/
 bool JDBConn::Connect(PJPARM sop)
 {
-	int      irc = RC_FX;
 	bool		 err = false;
 	jint     rc;
 	PGLOBAL& g = m_G;
diff --git a/storage/connect/tabrest.cpp b/storage/connect/tabrest.cpp
index 9c6b724973f..5dd29085d65 100644
--- a/storage/connect/tabrest.cpp
+++ b/storage/connect/tabrest.cpp
@@ -167,7 +167,7 @@ PQRYRES __stdcall ColREST(PGLOBAL g, PTOS tp, char *tab, char *db, bool info)
 #endif  // !MARIADB
 
   //  We used the file name relative to recorded datapath
-  strcat(strcat(strcat(strcpy(filename, "."), slash), db), slash);
+  strcat(strcat(strcat(strcpy(filename, "."), dir_slash), db), dir_slash);
   strncat(filename, fn, _MAX_PATH - strlen(filename));
 
   // Retrieve the file from the web and copy it locally
diff --git a/storage/connect/tabrest.h b/storage/connect/tabrest.h
index 9cf2d10a6b8..525b2bdc55f 100644
--- a/storage/connect/tabrest.h
+++ b/storage/connect/tabrest.h
@@ -5,10 +5,11 @@
 /***********************************************************************/
 #pragma once
 
+extern PCSZ slash;
 #if defined(__WIN__)
-static PCSZ slash = "\\";
+#define dir_slash "\\"
 #else // !__WIN__
-static PCSZ slash = "/";
+#define dir_slash "/"
 #define stricmp strcasecmp
 #endif // !__WIN__
 
diff --git a/storage/maria/s3_func.c b/storage/maria/s3_func.c
index 64f0d7f0ab2..6497a0f090a 100644
--- a/storage/maria/s3_func.c
+++ b/storage/maria/s3_func.c
@@ -72,7 +72,8 @@ static char *s3_wrap_strdup(const char *str)
 
 static void s3_wrap_free(void *ptr)
 {
-  my_free(ptr);
+  if (ptr)                                      /* Avoid tracing of null */
+    my_free(ptr);
 }
 
 void s3_init_library()
@@ -494,7 +495,7 @@ static my_bool copy_to_file(ms3_st *s3_client, const char *aws_bucket,
     if (s3_get_object(s3_client, aws_bucket, aws_path, &block, compression, 1))
       goto err;
 
-    error= my_write(file, block.str, block.length, MYF(MY_WME | MY_WME));
+    error= my_write(file, block.str, block.length, MYF(MY_WME | MY_FNABP));
     s3_free(&block);
     if (error == MY_FILE_ERROR)
       goto err;