Bug #19811005 ALTER TABLE ADD INDEX DOES NOT UPDATE INDEX_LENGTH IN I_S TABLES

PROBLEM
 =======
An add index doesn't update index length stats in information schema
TABLES table.

FIX
 ===
Update the dict_table_t variable with index length stats that is
actually calculated post alter . As this variable is used to populated
the information schema index length statistics.

Reviewed by: Bin su<bin.x.su@oracle.com>
RB: 21277

storage/innobase/dict/dict0stats.cc

 /*****************************************************************************
 
-Copyright (c) 2009, 2016, Oracle and/or its affiliates. All Rights Reserved.
+Copyright (c) 2009, 2019, Oracle and/or its affiliates. All Rights Reserved.
 Copyright (c) 2015, 2017, MariaDB Corporation.
 
 This program is free software; you can redistribute it and/or modify it under
@@ -2499,7 +2499,6 @@ dict_stats_report_error(
 	return (err);
 }
 
-
 /** Save the table's statistics into the persistent statistics storage.
 @param[in] table_orig	table whose stats to save
 @param[in] only_for_index if this is non-NULL, then stats for indexes
@@ -3208,6 +3207,8 @@ dict_stats_update_for_index(
 		if (dict_stats_persistent_storage_check(false)) {
 			dict_table_stats_lock(index->table, RW_X_LATCH);
 			dict_stats_analyze_index(index);
+			index->table->stat_sum_of_other_index_sizes
+				+= index->stat_index_size;
 			dict_table_stats_unlock(index->table, RW_X_LATCH);
 			dict_stats_save(index->table, &index->id);
 			DBUG_VOID_RETURN;

storage/xtradb/dict/dict0stats.cc

 /*****************************************************************************
 
-Copyright (c) 2009, 2016, Oracle and/or its affiliates. All Rights Reserved.
+Copyright (c) 2009, 2019, Oracle and/or its affiliates. All Rights Reserved.
 Copyright (c) 2015, 2017, MariaDB Corporation.
 
 This program is free software; you can redistribute it and/or modify it under
@@ -3207,6 +3207,8 @@ dict_stats_update_for_index(
 		if (dict_stats_persistent_storage_check(false)) {
 			dict_table_stats_lock(index->table, RW_X_LATCH);
 			dict_stats_analyze_index(index);
+			index->table->stat_sum_of_other_index_sizes
+				+= index->stat_index_size;
 			dict_table_stats_unlock(index->table, RW_X_LATCH);
 			dict_stats_save(index->table, &index->id);
 			DBUG_VOID_RETURN;
@@ -4006,7 +4008,6 @@ dict_stats_save_defrag_stats(
 {
 	dberr_t	ret;
 
-
 	if (index->is_readable()) {
 	} else {
 		return (dict_stats_report_error(index->table, true));