MDEV-14637: Fix hang due to persistent statistics

Similar to the tables SYS_FOREIGN and SYS_FOREIGN_COLS,
the tables mysql.innodb_table_stats and mysql.innodb_index_stats
are updated by the InnoDB internal SQL parser, which fails to
enforce the size limits of the data. Due to this, it is possible
for InnoDB to hang when there are persistent statistics defined on
partitioned tables where the total length of table name,
partition name and subpartition name exceeds the incorrectly
defined limit VARCHAR(64). That column should have been defined
as VARCHAR(199).

btr_node_ptr_max_size(): Interpret the VARCHAR(64) as VARCHAR(199),
to prevent a hang in the case that the upgrade script has not been
run.

dict_table_schema_check(): Ignore difference in the length of the
table_name column.

ha_innobase::max_supported_key_length(): For innodb_page_size=4k,
return a larger value so that the table mysql.innodb_index_stats
can be created. This could allow "impossible" tables to be created,
such that it is not possible to insert anything into a secondary
index when both the secondary key and the primary key are long,
but this is the easiest and most consistent way. The Oracle fix
would only ignore the maximum length violation for the two
statistics tables.

os_file_get_status_posix(), os_file_get_status_win32(): Handle
ENAMETOOLONG as well.

This patch is based on the following change in MySQL 5.7.23.
Not all changes were applied, and our variant allows persistent
statistics to work without hangs even if the table definitions
were not upgraded.

From fdbdce701ab8145ae234c9d401109dff4e4106cb Mon Sep 17 00:00:00 2001
From: Aditya A <aditya.a@oracle.com>
Date: Thu, 17 May 2018 16:11:43 +0530
Subject: [PATCH] Bug #26390736 THE FIELD TABLE_NAME (VARCHAR(64)) FROM
           MYSQL.INNODB_TABLE_STATS CAN OVERFLOW.

    In mysql.innodb_index_stats and mysql.innodb_table_stats
    tables the table name column didn't take into consideration
    partition names which can be more than varchar(64).

2 files changed, 2 insertions, 2 deletions

diff --git a/mysql-test/suite/innodb_gis/r/create_spatial_index.result b/mysql-test/suite/innodb_gis/r/create_spatial_index.result
index 71d3092c3b7..80632affb67 100644
--- a/mysql-test/suite/innodb_gis/r/create_spatial_index.result
+++ b/mysql-test/suite/innodb_gis/r/create_spatial_index.result
@@ -1284,7 +1284,7 @@ CREATE SPATIAL INDEX idx2 ON t1(c1);
 DROP TABLE t1;
 CREATE TABLE mysql.innodb_table_stats (
 database_name varchar(64) COLLATE utf8_bin NOT NULL,
-table_name varchar(64) COLLATE utf8_bin NOT NULL,
+table_name varchar(199) COLLATE utf8_bin NOT NULL,
 last_update timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
 n_rows bigint(20) unsigned NOT NULL,
 clustered_index_size bigint(20) unsigned NOT NULL,
diff --git a/mysql-test/suite/innodb_gis/t/create_spatial_index.test b/mysql-test/suite/innodb_gis/t/create_spatial_index.test
index d25a2e79793..6a15b0f2d74 100644
--- a/mysql-test/suite/innodb_gis/t/create_spatial_index.test
+++ b/mysql-test/suite/innodb_gis/t/create_spatial_index.test
@@ -1166,7 +1166,7 @@ CREATE SPATIAL INDEX idx2 ON t1(c1);
 DROP TABLE t1;
 CREATE TABLE mysql.innodb_table_stats (
   database_name varchar(64) COLLATE utf8_bin NOT NULL,
-  table_name varchar(64) COLLATE utf8_bin NOT NULL,
+  table_name varchar(199) COLLATE utf8_bin NOT NULL,
   last_update timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
   n_rows bigint(20) unsigned NOT NULL,
   clustered_index_size bigint(20) unsigned NOT NULL,