MDEV-7333 "'show table status like 'table_name'" on tokudb table lead to MariaDB crash

adjust enum values when reading them from frm

mysql-test/r/frm_bad_row_type-7333.result

+call mtr.add_suppression("bad_row_type.frm: invalid value 11 for the field row_format");
+select * from bad_row_type;
+category_id	category_name
+show create table bad_row_type;
+Table	Create Table
+bad_row_type	CREATE TABLE `bad_row_type` (
+  `category_id` int(11) NOT NULL AUTO_INCREMENT,
+  `category_name` varchar(255) DEFAULT NULL,
+  PRIMARY KEY (`category_id`)
+) ENGINE=MyISAM DEFAULT CHARSET=utf8
+show table status like 'bad_row_type';
+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
+bad_row_type	MyISAM	10	Dynamic	0	0	0	281474976710655	1024	0	1	x	x	NULL	utf8_general_ci	NULL		
+drop table bad_row_type;

mysql-test/t/frm_bad_row_type-7333.test

+#
+# MDEV-7333 "'show table status like 'table_name'" on tokudb table lead to MariaDB crash
+#
+let $datadir= `select @@datadir`;
+call mtr.add_suppression("bad_row_type.frm: invalid value 11 for the field row_format");
+copy_file std_data/bad_row_type.MYD $datadir/test/bad_row_type.MYD;
+copy_file std_data/bad_row_type.MYI $datadir/test/bad_row_type.MYI;
+copy_file std_data/bad_row_type.frm $datadir/test/bad_row_type.frm;
+
+select * from bad_row_type;
+show create table bad_row_type;
+replace_column 12 x 13 x;
+show table status like 'bad_row_type';
+drop table bad_row_type;

sql/handler.h

@@ -373,6 +373,9 @@ enum row_type { ROW_TYPE_NOT_USED=-1, ROW_TYPE_DEFAULT, ROW_TYPE_FIXED,
                 /** Unused. Reserved for future versions. */
                 ROW_TYPE_PAGE };
 
+/* not part of the enum, so that it shouldn't be in switch(row_type) */
+#define ROW_TYPE_MAX ((uint)ROW_TYPE_PAGE + 1)
+
 enum enum_binlog_func {
   BFN_RESET_LOGS=        1,
   BFN_RESET_SLAVE=       2,
@@ -1248,7 +1251,7 @@ class partition_info;
 struct st_partition_iter;
 #define NOT_A_PARTITION_ID ((uint32)-1)
 
-enum ha_choice { HA_CHOICE_UNDEF, HA_CHOICE_NO, HA_CHOICE_YES };
+enum ha_choice { HA_CHOICE_UNDEF, HA_CHOICE_NO, HA_CHOICE_YES, HA_CHOICE_MAX };
 
 typedef struct st_ha_create_information
 {

sql/table.cc

@@ -890,6 +890,23 @@ static bool create_key_infos(uchar *strpos, uint keys, KEY *keyinfo,
   return 0;
 }
 
+/** ensures that the enum value (read from frm) is within limits
+
+    if not - issues a warning and resets the value to 0
+    (that is, 0 is assumed to be a default value)
+*/
+static uint enum_value_with_check(THD *thd, TABLE_SHARE *share,
+                                  const char *name, uint value, uint limit)
+{
+  if (value < limit)
+    return value;
+
+  sql_print_warning("%s.frm: invalid value %d for the field %s",
+                share->normalized_path.str, value, name);
+  return 0;
+}
+
+
 /*
   Read data from a binary .frm file from MySQL 3.23 - 5.0 into TABLE_SHARE
 */
@@ -983,9 +1000,12 @@ static int open_binary_frm(THD *thd, TABLE_SHARE *share, uchar *head,
   if (!head[32])				// New frm file in 3.23
   {
     share->avg_row_length= uint4korr(head+34);
-    share->transactional= (ha_choice) (head[39] & 3);
-    share->page_checksum= (ha_choice) ((head[39] >> 2) & 3);
-    share->row_type= (row_type) head[40];
+    share->transactional= (ha_choice)
+      enum_value_with_check(thd, share, "transactional", (head[39] & 3), HA_CHOICE_MAX);
+    share->page_checksum= (ha_choice)
+      enum_value_with_check(thd, share, "page_checksum", (head[39] >> 2) & 3, HA_CHOICE_MAX);
+    share->row_type= (row_type)
+      enum_value_with_check(thd, share, "row_format", head[40], ROW_TYPE_MAX);
     share->table_charset= get_charset((((uint) head[41]) << 8) + 
                                         (uint) head[38],MYF(0));
     share->null_field_first= 1;