BUG#21173: SHOW TABLE STATUS crashes on InnoDB tables

Don't use get_auto_increment on tables without auto_increment fields

mysql-test/r/partition.result

 drop table if exists t1;
 create table t1 (a int)
+engine = innodb
+partition by key (a);
+insert into t1 values (0);
+show table status;
+Name	Engine	Version	Row_format	Rows	Avg_row_length	Data_length	Max_data_length	Index_length	Data_free	Auto_increment	Create_time	Update_time	Check_time	Collation	Checksum	Create_options	Comment
+t1	InnoDB	10	Compact	2	8192	16384	0	0	0	NULL	NULL	NULL	NULL	latin1_swedish_ci	NULL	partitioned	
+drop table t1;
+create table t1 (a int)
 partition by list (a)
 (partition p0 values in (1));
 create procedure pz()

mysql-test/t/partition.test

@@ -9,6 +9,16 @@
 drop table if exists t1;
 --enable_warnings
 
+#
+# Bug 21173: SHOW TABLE STATUS crashes server in InnoDB
+#
+create table t1 (a int)
+engine = innodb
+partition by key (a);
+insert into t1 values (0);
+show table status;
+drop table t1;
+
 #
 # Bug 19309 Partitions: Crash if double procedural alter
 #

sql/ha_partition.cc

@@ -4183,10 +4183,16 @@ void ha_partition::info(uint flag)
     ulonglong nb_reserved_values;
     DBUG_PRINT("info", ("HA_STATUS_AUTO"));
     /* we don't want to reserve any values, it's pure information */
+
+    if (table->found_next_number_field)
+    {
       get_auto_increment(0, 0, 0, &stats.auto_increment_value,
                          &nb_reserved_values);
       release_auto_increment();
     }
+    else
+      stats.auto_increment_value= ~(ulonglong)(0);
+  }
   if (flag & HA_STATUS_VARIABLE)
   {
     DBUG_PRINT("info", ("HA_STATUS_VARIABLE"));
@@ -5363,7 +5369,6 @@ void ha_partition::get_auto_increment(ulonglong offset, ulonglong increment,
   if (increment)                                // If not check for values
     *nb_reserved_values= (last_value == ULONGLONG_MAX) ?
       ULONGLONG_MAX : ((last_value - *first_value) / increment);
-
   DBUG_VOID_RETURN;
 }