Merge 10.1 into 10.2

16 files changed, 261 insertions, 26 deletions

diff --git a/sql/field.h b/sql/field.h
index 22c276478b6..ae6adec07e8 100644
--- a/sql/field.h
+++ b/sql/field.h
@@ -1448,6 +1448,17 @@ public:
   /* Hash value */
   virtual void hash(ulong *nr, ulong *nr2);
 
+  /**
+    Get the upper limit of the MySQL integral and floating-point type.
+
+    @return maximum allowed value for the field
+  */
+  virtual ulonglong get_max_int_value() const
+  {
+    DBUG_ASSERT(false);
+    return 0ULL;
+  }
+
 /**
   Checks whether a string field is part of write_set.
 
@@ -2006,6 +2017,11 @@ public:
     *to= *from;
     return from + 1;
   }
+
+  virtual ulonglong get_max_int_value() const
+  {
+    return unsigned_flag ? 0xFFULL : 0x7FULL;
+  }
 };
 
 
@@ -2047,6 +2063,10 @@ public:
   virtual const uchar *unpack(uchar* to, const uchar *from,
                               const uchar *from_end, uint param_data)
   { return unpack_int16(to, from, from_end); }
+  virtual ulonglong get_max_int_value() const
+  {
+    return unsigned_flag ? 0xFFFFULL : 0x7FFFULL;
+  }
 };
 
 class Field_medium :public Field_integer {
@@ -2080,6 +2100,10 @@ public:
   {
     return Field::pack(to, from, max_length);
   }
+  virtual ulonglong get_max_int_value() const
+  {
+    return unsigned_flag ? 0xFFFFFFULL : 0x7FFFFFULL;
+  }
 };
 
 
@@ -2125,6 +2149,10 @@ public:
   {
     return unpack_int32(to, from, from_end);
   }
+  virtual ulonglong get_max_int_value() const
+  {
+    return unsigned_flag ? 0xFFFFFFFFULL : 0x7FFFFFFFULL;
+  }
 };
 
 
@@ -2174,6 +2202,10 @@ public:
   {
     return unpack_int64(to, from, from_end);
   }
+  virtual ulonglong get_max_int_value() const
+  {
+    return unsigned_flag ? 0xFFFFFFFFFFFFFFFFULL : 0x7FFFFFFFFFFFFFFFULL;
+  }
 };
 
 
@@ -2213,6 +2245,13 @@ public:
   uint32 pack_length() const { return sizeof(float); }
   uint row_pack_length() const { return pack_length(); }
   void sql_type(String &str) const;
+  virtual ulonglong get_max_int_value() const
+  {
+    /*
+      We use the maximum as per IEEE754-2008 standard, 2^24
+    */
+    return 0x1000000ULL;
+  }
 private:
   int do_save_field_metadata(uchar *first_byte);
 };
@@ -2265,6 +2304,13 @@ public:
   uint32 pack_length() const { return sizeof(double); }
   uint row_pack_length() const { return pack_length(); }
   void sql_type(String &str) const;
+  virtual ulonglong get_max_int_value() const
+  {
+    /*
+      We use the maximum as per IEEE754-2008 standard, 2^53
+    */
+    return 0x20000000000000ULL;
+  }
 private:
   int do_save_field_metadata(uchar *first_byte);
 };
diff --git a/sql/handler.cc b/sql/handler.cc
index 36babb96415..2fadef3044f 100644
--- a/sql/handler.cc
+++ b/sql/handler.cc
@@ -2853,9 +2853,15 @@ compute_next_insert_id(ulonglong nr,struct system_variables *variables)
     nr= nr + 1; // optimization of the formula below
   else
   {
+    /*
+       Calculating the number of complete auto_increment_increment extents:
+    */
     nr= (((nr+ variables->auto_increment_increment -
            variables->auto_increment_offset)) /
          (ulonglong) variables->auto_increment_increment);
+    /*
+       Adding an offset to the auto_increment_increment extent boundary:
+    */
     nr= (nr* (ulonglong) variables->auto_increment_increment +
          variables->auto_increment_offset);
   }
@@ -2911,8 +2917,14 @@ prev_insert_id(ulonglong nr, struct system_variables *variables)
   }
   if (variables->auto_increment_increment == 1)
     return nr; // optimization of the formula below
+  /*
+    Calculating the number of complete auto_increment_increment extents:
+  */
   nr= (((nr - variables->auto_increment_offset)) /
        (ulonglong) variables->auto_increment_increment);
+  /*
+    Adding an offset to the auto_increment_increment extent boundary:
+  */
   return (nr * (ulonglong) variables->auto_increment_increment +
           variables->auto_increment_offset);
 }
@@ -3135,10 +3147,23 @@ int handler::update_auto_increment()
   if (unlikely(tmp))                            // Out of range value in store
   {
     /*
-      It's better to return an error here than getting a confusing
-      'duplicate key error' later.
+      first test if the query was aborted due to strict mode constraints
+    */
+    if (thd->killed == KILL_BAD_DATA ||
+        nr > table->next_number_field->get_max_int_value())
+      DBUG_RETURN(HA_ERR_AUTOINC_ERANGE);
+
+    /*
+      field refused this value (overflow) and truncated it, use the result of
+      the truncation (which is going to be inserted); however we try to
+      decrease it to honour auto_increment_* variables.
+      That will shift the left bound of the reserved interval, we don't
+      bother shifting the right bound (anyway any other value from this
+      interval will cause a duplicate key).
     */
-    result= HA_ERR_AUTOINC_ERANGE;
+    nr= prev_insert_id(table->next_number_field->val_int(), variables);
+    if (unlikely(table->next_number_field->store((longlong) nr, TRUE)))
+      nr= table->next_number_field->val_int();
   }
   if (append)
   {
diff --git a/sql/item.cc b/sql/item.cc
index 58d2b7dbfc0..7d8baf81d3b 100644
--- a/sql/item.cc
+++ b/sql/item.cc
@@ -7402,7 +7402,7 @@ Item_direct_view_ref::derived_grouping_field_transformer_for_where(THD *thd,
 void Item_field::print(String *str, enum_query_type query_type)
 {
   if (field && field->table->const_table &&
-      !(query_type & QT_NO_DATA_EXPANSION))
+      !(query_type & (QT_NO_DATA_EXPANSION | QT_VIEW_INTERNAL)))
   {
     print_value(str);
     return;
diff --git a/sql/item_cmpfunc.cc b/sql/item_cmpfunc.cc
index 6834820c0b5..577a98df0d2 100644
--- a/sql/item_cmpfunc.cc
+++ b/sql/item_cmpfunc.cc
@@ -5119,7 +5119,11 @@ longlong Item_func_isnull::val_int()
 
 void Item_func_isnull::print(String *str, enum_query_type query_type)
 {
-  args[0]->print_parenthesised(str, query_type, precedence());
+  if (const_item() && !args[0]->maybe_null &&
+      !(query_type & (QT_NO_DATA_EXPANSION | QT_VIEW_INTERNAL)))
+    str->append("/*always not null*/ 1");
+  else
+    args[0]->print_parenthesised(str, query_type, precedence());
   str->append(STRING_WITH_LEN(" is null"));
 }
 
diff --git a/sql/key.cc b/sql/key.cc
index 08bd6e8f65d..116f2954d9e 100644
--- a/sql/key.cc
+++ b/sql/key.cc
@@ -146,7 +146,8 @@ void key_copy(uchar *to_key, uchar *from_record, KEY *key_info,
     {
       key_length-= HA_KEY_BLOB_LENGTH;
       length= MY_MIN(key_length, key_part->length);
-      uint bytes= key_part->field->get_key_image(to_key, length, Field::itRAW);
+      uint bytes= key_part->field->get_key_image(to_key, length,
+		      key_info->flags & HA_SPATIAL ? Field::itMBR : Field::itRAW);
       if (with_zerofill && bytes < length)
         bzero((char*) to_key + bytes, length - bytes);
       to_key+= HA_KEY_BLOB_LENGTH;
diff --git a/sql/mysqld.cc b/sql/mysqld.cc
index 2ad4e6f2a61..1c45d07beed 100644
--- a/sql/mysqld.cc
+++ b/sql/mysqld.cc
@@ -1469,9 +1469,9 @@ static	 NTService  Service;	      ///< Service object for WinNT
 #endif /* __WIN__ */
 
 #ifdef _WIN32
+#include <sddl.h> /* ConvertStringSecurityDescriptorToSecurityDescriptor */
 static char pipe_name[512];
 static SECURITY_ATTRIBUTES saPipeSecurity;
-static SECURITY_DESCRIPTOR sdPipeDescriptor;
 static HANDLE hPipe = INVALID_HANDLE_VALUE;
 #endif
 
@@ -2719,21 +2719,20 @@ static void network_init(void)
 
     strxnmov(pipe_name, sizeof(pipe_name)-1, "\\\\.\\pipe\\",
 	     mysqld_unix_port, NullS);
-    bzero((char*) &saPipeSecurity, sizeof(saPipeSecurity));
-    bzero((char*) &sdPipeDescriptor, sizeof(sdPipeDescriptor));
-    if (!InitializeSecurityDescriptor(&sdPipeDescriptor,
-				      SECURITY_DESCRIPTOR_REVISION))
+    /*
+      Create a security descriptor for pipe.
+      - Use low integrity level, so that it is possible to connect
+      from any process.
+      - Give Everyone read/write access to pipe.
+    */
+    if (!ConvertStringSecurityDescriptorToSecurityDescriptor(
+         "S:(ML;; NW;;; LW) D:(A;; FRFW;;; WD)",
+         SDDL_REVISION_1, &saPipeSecurity.lpSecurityDescriptor, NULL))
     {
       sql_perror("Can't start server : Initialize security descriptor");
       unireg_abort(1);
     }
-    if (!SetSecurityDescriptorDacl(&sdPipeDescriptor, TRUE, NULL, FALSE))
-    {
-      sql_perror("Can't start server : Set security descriptor");
-      unireg_abort(1);
-    }
     saPipeSecurity.nLength = sizeof(SECURITY_ATTRIBUTES);
-    saPipeSecurity.lpSecurityDescriptor = &sdPipeDescriptor;
     saPipeSecurity.bInheritHandle = FALSE;
     if ((hPipe= CreateNamedPipe(pipe_name,
         PIPE_ACCESS_DUPLEX | FILE_FLAG_OVERLAPPED | FILE_FLAG_FIRST_PIPE_INSTANCE,
@@ -4320,6 +4319,20 @@ static int init_common_variables()
   DBUG_PRINT("info",("%s  Ver %s for %s on %s\n",my_progname,
 		     server_version, SYSTEM_TYPE,MACHINE_TYPE));
 
+#ifdef WITH_WSREP
+  /*
+    We need to initialize auxiliary variables, that will be
+    further keep the original values of auto-increment options
+    as they set by the user. These variables used to restore
+    user-defined values of the auto-increment options after
+    setting of the wsrep_auto_increment_control to 'OFF'.
+  */
+  global_system_variables.saved_auto_increment_increment=
+    global_system_variables.auto_increment_increment;
+  global_system_variables.saved_auto_increment_offset=
+    global_system_variables.auto_increment_offset;
+#endif /* WITH_WSREP */
+
 #ifdef HAVE_LINUX_LARGE_PAGES
   /* Initialize large page size */
   if (opt_large_pages)
@@ -6901,6 +6914,7 @@ pthread_handler_t handle_connections_namedpipes(void *arg)
     connect->host= my_localhost;
     create_new_thread(connect);
   }
+  LocalFree(saPipeSecurity.lpSecurityDescriptor);
   CloseHandle(connectOverlapped.hEvent);
   DBUG_LEAVE;
   decrement_handler_count();
diff --git a/sql/protocol.cc b/sql/protocol.cc
index b9d9f28831e..256cecac6bb 100644
--- a/sql/protocol.cc
+++ b/sql/protocol.cc
@@ -710,7 +710,7 @@ uchar *net_store_data(uchar *to, const uchar *from, size_t length)
 
 uchar *net_store_data(uchar *to,int32 from)
 {
-  char buff[20];
+  char buff[22];
   uint length=(uint) (int10_to_str(from,buff,10)-buff);
   to=net_store_length_fast(to,length);
   memcpy(to,buff,length);
@@ -1136,7 +1136,7 @@ bool Protocol_text::store_tiny(longlong from)
   DBUG_ASSERT(field_types == 0 || field_types[field_pos] == MYSQL_TYPE_TINY);
   field_pos++;
 #endif
-  char buff[20];
+  char buff[22];
   return net_store_data((uchar*) buff,
 			(size_t) (int10_to_str((int) from, buff, -10) - buff));
 }
@@ -1150,7 +1150,7 @@ bool Protocol_text::store_short(longlong from)
 	      field_types[field_pos] == MYSQL_TYPE_SHORT);
   field_pos++;
 #endif
-  char buff[20];
+  char buff[22];
   return net_store_data((uchar*) buff,
 			(size_t) (int10_to_str((int) from, buff, -10) -
                                   buff));
@@ -1165,7 +1165,7 @@ bool Protocol_text::store_long(longlong from)
               field_types[field_pos] == MYSQL_TYPE_LONG);
   field_pos++;
 #endif
-  char buff[20];
+  char buff[22];
   return net_store_data((uchar*) buff,
 			(size_t) (int10_to_str((long int)from, buff,
                                                (from <0)?-10:10)-buff));
diff --git a/sql/sql_class.h b/sql/sql_class.h
index 4888b38bc30..9a10083a998 100644
--- a/sql/sql_class.h
+++ b/sql/sql_class.h
@@ -569,6 +569,17 @@ typedef struct system_variables
   ha_rows max_join_size;
   ha_rows expensive_subquery_limit;
   ulong auto_increment_increment, auto_increment_offset;
+#ifdef WITH_WSREP
+  /*
+    Variables with stored values of the auto_increment_increment
+    and auto_increment_offset options that are will be needed when
+    wsrep_auto_increment_control will be set to 'OFF', because the
+    setting it to 'ON' leads to overwriting of the original values
+    (which are set by the user) by calculated values (which are
+    based on the cluster's size):
+  */
+  ulong saved_auto_increment_increment, saved_auto_increment_offset;
+#endif /* WITH_WSREP */
   uint eq_range_index_dive_limit;
   ulong lock_wait_timeout;
   ulong join_cache_level;
diff --git a/sql/sql_list.h b/sql/sql_list.h
index c27ed44cb9c..47590920510 100644
--- a/sql/sql_list.h
+++ b/sql/sql_list.h
@@ -311,10 +311,13 @@ public:
   */
   inline void swap(base_list &rhs)
   {
+    list_node **rhs_last=rhs.last;
     swap_variables(list_node *, first, rhs.first);
-    swap_variables(list_node **, last, rhs.last);
     swap_variables(uint, elements, rhs.elements);
+    rhs.last= last == &first ? &rhs.first : last;
+    last = rhs_last == &rhs.first ? &first : rhs_last;
   }
+
   inline list_node* last_node() { return *last; }
   inline list_node* first_node() { return first;}
   inline void *head() { return first->info; }
diff --git a/sql/sql_select.cc b/sql/sql_select.cc
index b94ca496b95..0124a782de0 100644
--- a/sql/sql_select.cc
+++ b/sql/sql_select.cc
@@ -1564,6 +1564,14 @@ JOIN::optimize_inner()
       error= 1;
       DBUG_RETURN(1);
     }
+    if (!group_list)
+    {
+      /* The output has only one row */
+      order=0;
+      simple_order=1;
+      group_optimized_away= 1;
+      select_distinct=0;
+    }
   }
   
   /* Calculate how to do the join */
@@ -6099,7 +6107,7 @@ add_group_and_distinct_keys(JOIN *join, JOIN_TAB *join_tab)
   Item_field *cur_item;
   key_map possible_keys(0);
 
-  if (join->group_list || join->simple_group)
+  if (join->group_list)
   { /* Collect all query fields referenced in the GROUP clause. */
     for (cur_group= join->group_list; cur_group; cur_group= cur_group->next)
       (*cur_group->item)->walk(&Item::collect_item_field_processor, 0,
diff --git a/sql/sql_show.cc b/sql/sql_show.cc
index b9c90f7fb4b..6af64b3bb11 100644
--- a/sql/sql_show.cc
+++ b/sql/sql_show.cc
@@ -2474,7 +2474,7 @@ static int show_create_view(THD *thd, TABLE_LIST *table, String *buff)
     We can't just use table->query, because our SQL_MODE may trigger
     a different syntax, like when ANSI_QUOTES is defined.
   */
-  table->view->unit.print(buff, enum_query_type(QT_ORDINARY |
+  table->view->unit.print(buff, enum_query_type(QT_VIEW_INTERNAL |
                                                 QT_ITEM_ORIGINAL_FUNC_NULLIF));
 
   if (table->with_check != VIEW_CHECK_NONE)
diff --git a/sql/sql_time.cc b/sql/sql_time.cc
index e3116f73edc..cdb9f4e5b79 100644
--- a/sql/sql_time.cc
+++ b/sql/sql_time.cc
@@ -190,7 +190,7 @@ bool get_date_from_daynr(long daynr,uint *ret_year,uint *ret_month,
 ulong convert_period_to_month(ulong period)
 {
   ulong a,b;
-  if (period == 0)
+  if (period == 0 || period > 999912)
     return 0L;
   if ((a=period/100) < YY_PART_YEAR)
     a+=2000;
diff --git a/sql/sys_vars.cc b/sql/sys_vars.cc
index 391772d1191..5541efbcead 100644
--- a/sql/sys_vars.cc
+++ b/sql/sys_vars.cc
@@ -347,13 +347,56 @@ static Sys_var_long Sys_pfs_connect_attrs_size(
 
 #endif /* WITH_PERFSCHEMA_STORAGE_ENGINE */
 
+#ifdef WITH_WSREP
+
+/*
+  We need to keep the original values set by the user, as they will
+  be lost if wsrep_auto_increment_control set to 'ON':
+*/
+static bool update_auto_increment_increment (sys_var *self, THD *thd, enum_var_type type)
+{
+  if (type == OPT_GLOBAL)
+    global_system_variables.saved_auto_increment_increment=
+      global_system_variables.auto_increment_increment;
+  else
+    thd->variables.saved_auto_increment_increment=
+      thd->variables.auto_increment_increment;
+  return false;
+}
+
+#endif /* WITH_WSREP */
+
 static Sys_var_ulong Sys_auto_increment_increment(
        "auto_increment_increment",
        "Auto-increment columns are incremented by this",
        SESSION_VAR(auto_increment_increment),
        CMD_LINE(OPT_ARG),
        VALID_RANGE(1, 65535), DEFAULT(1), BLOCK_SIZE(1),
+#ifdef WITH_WSREP
+       NO_MUTEX_GUARD, IN_BINLOG, ON_CHECK(0),
+       ON_UPDATE(update_auto_increment_increment));
+#else
        NO_MUTEX_GUARD, IN_BINLOG);
+#endif /* WITH_WSREP */
+
+#ifdef WITH_WSREP
+
+/*
+  We need to keep the original values set by the user, as they will
+  be lost if wsrep_auto_increment_control set to 'ON':
+*/
+static bool update_auto_increment_offset (sys_var *self, THD *thd, enum_var_type type)
+{
+  if (type == OPT_GLOBAL)
+    global_system_variables.saved_auto_increment_offset=
+      global_system_variables.auto_increment_offset;
+  else
+    thd->variables.saved_auto_increment_offset=
+      thd->variables.auto_increment_offset;
+  return false;
+}
+
+#endif /* WITH_WSREP */
 
 static Sys_var_ulong Sys_auto_increment_offset(
        "auto_increment_offset",
@@ -362,7 +405,12 @@ static Sys_var_ulong Sys_auto_increment_offset(
        SESSION_VAR(auto_increment_offset),
        CMD_LINE(OPT_ARG),
        VALID_RANGE(1, 65535), DEFAULT(1), BLOCK_SIZE(1),
+#ifdef WITH_WSREP
+       NO_MUTEX_GUARD, IN_BINLOG, ON_CHECK(0),
+       ON_UPDATE(update_auto_increment_offset));
+#else
        NO_MUTEX_GUARD, IN_BINLOG);
+#endif /* WITH_WSREP */
 
 static Sys_var_mybool Sys_automatic_sp_privileges(
        "automatic_sp_privileges",
@@ -4976,11 +5024,54 @@ static Sys_var_ulong Sys_wsrep_retry_autocommit(
        SESSION_VAR(wsrep_retry_autocommit), CMD_LINE(REQUIRED_ARG),
        VALID_RANGE(0, 10000), DEFAULT(1), BLOCK_SIZE(1));
 
+static bool update_wsrep_auto_increment_control (sys_var *self, THD *thd, enum_var_type type)
+{
+  if (wsrep_auto_increment_control)
+  {
+    /*
+      The variables that control auto increment shall be calculated
+      automaticaly based on the size of the cluster. This usually done
+      within the wsrep_view_handler_cb callback. However, if the user
+      manually sets the value of wsrep_auto_increment_control to 'ON',
+      then we should to re-calculate these variables again (because
+      these values may be required before wsrep_view_handler_cb will
+      be re-invoked, which is rarely invoked if the cluster stays in
+      the stable state):
+    */
+    global_system_variables.auto_increment_increment=
+       wsrep_cluster_size ? wsrep_cluster_size : 1;
+    global_system_variables.auto_increment_offset=
+       wsrep_local_index >= 0 ? wsrep_local_index + 1 : 1;
+    thd->variables.auto_increment_increment=
+      global_system_variables.auto_increment_increment;
+    thd->variables.auto_increment_offset=
+      global_system_variables.auto_increment_offset;
+  }
+  else
+  {
+    /*
+      We must restore the last values of the variables that
+      are explicitly specified by the user:
+    */
+    global_system_variables.auto_increment_increment=
+      global_system_variables.saved_auto_increment_increment;
+    global_system_variables.auto_increment_offset=
+      global_system_variables.saved_auto_increment_offset;
+    thd->variables.auto_increment_increment=
+      thd->variables.saved_auto_increment_increment;
+    thd->variables.auto_increment_offset=
+      thd->variables.saved_auto_increment_offset;
+  }
+  return false;
+}
+
 static Sys_var_mybool Sys_wsrep_auto_increment_control(
        "wsrep_auto_increment_control", "To automatically control the "
        "assignment of autoincrement variables",
        GLOBAL_VAR(wsrep_auto_increment_control), 
-       CMD_LINE(OPT_ARG), DEFAULT(TRUE));
+       CMD_LINE(OPT_ARG), DEFAULT(TRUE),
+       NO_MUTEX_GUARD, NOT_IN_BINLOG, ON_CHECK(0),
+       ON_UPDATE(update_wsrep_auto_increment_control));
 
 static Sys_var_mybool Sys_wsrep_drupal_282555_workaround(
        "wsrep_drupal_282555_workaround", "Enable a workaround to handle the "
diff --git a/sql/wsrep_mysqld.h b/sql/wsrep_mysqld.h
index 8d92621001b..b8143e92ccb 100644
--- a/sql/wsrep_mysqld.h
+++ b/sql/wsrep_mysqld.h
@@ -160,6 +160,10 @@ extern "C" query_id_t wsrep_thd_query_id(THD *thd);
 extern "C" query_id_t wsrep_thd_wsrep_last_query_id(THD *thd);
 extern "C" void wsrep_thd_set_wsrep_last_query_id(THD *thd, query_id_t id);
 
+extern "C" void wsrep_thd_auto_increment_variables(THD*,
+                                                   unsigned long long *offset,
+                                                   unsigned long long *increment);
+
 extern void wsrep_close_client_connections(my_bool wait_to_end);
 extern int  wsrep_wait_committing_connections_close(int wait_time);
 extern void wsrep_close_applier(THD *thd);
diff --git a/sql/wsrep_thd.cc b/sql/wsrep_thd.cc
index 15eed2e10e6..1621559bb8a 100644
--- a/sql/wsrep_thd.cc
+++ b/sql/wsrep_thd.cc
@@ -677,3 +677,25 @@ bool wsrep_thd_has_explicit_locks(THD *thd)
   assert(thd);
   return thd->mdl_context.has_explicit_locks();
 }
+
+/*
+  Get auto increment variables for THD. Use global settings for
+  applier threads.
+ */
+extern "C"
+void wsrep_thd_auto_increment_variables(THD* thd,
+                                        unsigned long long* offset,
+                                        unsigned long long* increment)
+{
+  if (thd->wsrep_exec_mode == REPL_RECV &&
+      thd->wsrep_conflict_state != REPLAYING)
+  {
+    *offset= global_system_variables.auto_increment_offset;
+    *increment= global_system_variables.auto_increment_increment;
+  }
+  else
+  {
+    *offset= thd->variables.auto_increment_offset;
+    *increment= thd->variables.auto_increment_increment;
+  }
+}
diff --git a/sql/wsrep_var.cc b/sql/wsrep_var.cc
index bd33847762d..9c7698aec39 100644
--- a/sql/wsrep_var.cc
+++ b/sql/wsrep_var.cc
@@ -617,6 +617,12 @@ bool wsrep_desync_check (sys_var *self, THD* thd, set_var* var)
     return true;
   }
 
+  if (thd->global_read_lock.is_acquired())
+  {
+    my_message (ER_CANNOT_USER, "Global read lock acquired. Can't set 'wsrep_desync'", MYF(0));
+    return true;
+  }
+
   bool new_wsrep_desync= (bool) var->save_result.ulonglong_value;
   if (wsrep_desync == new_wsrep_desync) {
     if (new_wsrep_desync) {