MDEV-6424: Mariadb server crashes with assertion failure in file ha_innodb.cc

Analysis: For some reason table stats for a table pointed from a index 
is not initialized. Added additional warning output on this situation
and table stats initialization. This is better than asserting.

mysql-test/suite/innodb/r/innodb-stats-initialize-failure.result

+call mtr.add_suppression("InnoDB: Warning: Index.*");
+set DEBUG_DBUG='+d,ib_ha_innodb_stat_not_initialized';
+create table t1(a int not null primary key, b int, c int, key(b), key(c)) engine=innodb;
+create procedure innodb_insert_proc (repeat_count int)
+begin
+declare current_num int;
+set current_num = 0;
+while current_num < repeat_count do
+insert into t1 values(current_num, current_num, current_num);
+set current_num = current_num + 1;
+end while;
+end//
+commit;
+set autocommit=0;
+call innodb_insert_proc(10000);
+commit;
+set autocommit=1;
+select count(1) from t1;
+count(1)
+10000
+select count(1) from t1 where a between 5 and 100;
+count(1)
+96
+select count(1) from t1 where b between 5 and 256;
+count(1)
+252
+select count(1) from t1 where c between 7 and 787;
+count(1)
+781
+set DEBUG_DBUG=NULL;
+drop procedure innodb_insert_proc;
+drop table t1;

mysql-test/suite/innodb/t/innodb-stats-initialize-failure.test

+# MDEV-6424: Mariadb server crashes with assertion failure in file ha_innodb.cc
+--source include/have_innodb.inc
+
+# DEBUG_SYNC must be compiled in.
+--source include/have_debug_sync.inc
+
+call mtr.add_suppression("InnoDB: Warning: Index.*");
+# This caused crash earlier
+set DEBUG_DBUG='+d,ib_ha_innodb_stat_not_initialized';
+create table t1(a int not null primary key, b int, c int, key(b), key(c)) engine=innodb;
+
+delimiter //;
+create procedure innodb_insert_proc (repeat_count int)
+begin
+  declare current_num int;
+  set current_num = 0;
+  while current_num < repeat_count do
+    insert into t1 values(current_num, current_num, current_num);
+    set current_num = current_num + 1;
+  end while;
+end//
+delimiter ;//
+commit;
+
+set autocommit=0;
+call innodb_insert_proc(10000);
+commit;
+set autocommit=1;
+
+select count(1) from t1;
+select count(1) from t1 where a between 5 and 100;
+select count(1) from t1 where b between 5 and 256;
+select count(1) from t1 where c between 7 and 787;
+
+set DEBUG_DBUG=NULL;
+
+drop procedure innodb_insert_proc;
+drop table t1;
+

storage/innobase/handler/ha_innodb.cc

@@ -4,6 +4,7 @@ Copyright (c) 2000, 2014, Oracle and/or its affiliates. All Rights Reserved.
 Copyright (c) 2008, 2009 Google Inc.
 Copyright (c) 2009, Percona Inc.
 Copyright (c) 2012, Facebook Inc.
+Copyright (c) 2013, 2014 SkySQL Ab. All Rights Reserved.
 
 Portions of this file contain modifications contributed and copyrighted by
 Google, Inc. Those modifications are gratefully acknowledged and are described
@@ -11444,6 +11445,34 @@ ha_innobase::info_low(
 					break;
 				}
 
+	DBUG_EXECUTE_IF("ib_ha_innodb_stat_not_initialized",
+					index->table->stat_initialized = FALSE;);
+
+				if (!ib_table->stat_initialized ||
+					(index->table != ib_table ||
+						!index->table->stat_initialized)) {
+					fprintf(stderr,
+						"InnoDB: Warning: Index %s points to table %s"									        " and ib_table %s statistics is initialized %d "
+						" but index table %s initialized %d "
+					        " mysql table is %s. Have you mixed "
+						"up .frm files from different "
+					       	"installations? "
+						"See " REFMAN
+						"innodb-troubleshooting.html\n",
+						index->name,
+						index->table->name,
+						ib_table->name,
+						ib_table->stat_initialized,
+						index->table->name,
+						index->table->stat_initialized,
+						table->s->table_name.str
+						);
+
+					/* This is better than
+					assert on below function */
+					dict_stats_init(index->table);
+				}
+
 				rec_per_key = innodb_rec_per_key(
 					index, j, stats.records);
 

storage/xtradb/handler/ha_innodb.cc

@@ -4,6 +4,7 @@ Copyright (c) 2000, 2014, Oracle and/or its affiliates. All Rights Reserved.
 Copyright (c) 2008, 2009 Google Inc.
 Copyright (c) 2009, Percona Inc.
 Copyright (c) 2012, Facebook Inc.
+Copyright (c) 2013, 2014 SkySQL Ab. All Rights Reserved.
 
 Portions of this file contain modifications contributed and copyrighted by
 Google, Inc. Those modifications are gratefully acknowledged and are described
@@ -97,6 +98,7 @@ this program; if not, write to the Free Software Foundation, Inc.,
 #include "fts0types.h"
 #include "row0import.h"
 #include "row0quiesce.h"
+#include "row0mysql.h"
 #ifdef UNIV_DEBUG
 #include "trx0purge.h"
 #endif /* UNIV_DEBUG */
@@ -12010,6 +12012,35 @@ ha_innobase::info_low(
 					break;
 				}
 
+				DBUG_EXECUTE_IF("ib_ha_innodb_stat_not_initialized",
+					index->table->stat_initialized = FALSE;);
+
+				if (!ib_table->stat_initialized ||
+					(index->table != ib_table ||
+						!index->table->stat_initialized)) {
+					fprintf(stderr,
+						"InnoDB: Warning: Index %s points to table %s"
+					        " and ib_table %s statistics is initialized %d "
+						" but index table %s initialized %d "
+					        " mysql table is %s. Have you mixed "
+						"up .frm files from different "
+					       	"installations? "
+						"See " REFMAN
+						"innodb-troubleshooting.html\n",
+						index->name,
+						index->table->name,
+						ib_table->name,
+						ib_table->stat_initialized,
+						index->table->name,
+						index->table->stat_initialized,
+						table->s->table_name.str
+						);
+
+					/* This is better than
+					assert on below function */
+					dict_stats_init(index->table);
+				}
+
 				rec_per_key = innodb_rec_per_key(
 					index, j, stats.records);