Backtrace:

#8 0x006b0d98 in __assert_fail () from /lib/libc.so.6
#9 0x087bd753 in decimal_bin_size (precision=0, scale=0) at decimal.c:1459
#10 0x0875be80 in dynamic_column_value_len (value=0xae632e0c) at ma_dyncol.c:334
#11 0x0875d27a in dynamic_column_create_many_internal (str=0xae99ef44, column_count=2, column_numbers=0xae632e48, values=0xae632dd0, new_str=1 '\001')
at ma_dyncol.c:1117
#12 0x0875d371 in dynamic_column_create_many (str=0xae99ef44, column_count=2, column_numbers=0xae632e48, values=0xae632dd0) at ma_dyncol.c:1157
#13 0x08220ccd in Item_func_dyncol_create::val_str (this=0xae614798, str=0xae632b54) at item_strfunc.cc:3640
#14 0x0820579a in Arg_comparator::compare_binary_string (this=0xae632b08) at item_cmpfunc.cc:1323
#15 0x081eaa06 in Arg_comparator::compare (this=0xae632b08) at item_cmpfunc.h:82
#16 0x082075ea in Item_func_eq::val_int (this=0xae632a88) at item_cmpfunc.cc:2078
#17 0x0832f452 in evaluate_join_record (join=0xae666ac0, join_tab=0xae633328, error=0) at sql_select.cc:14061
#18 0x0832f205 in sub_select (join=0xae666ac0, join_tab=0xae633328, end_of_records=false) at sql_select.cc:14006
#19 0x0832e48f in do_select (join=0xae666ac0, fields=0xa03e9a8, table=0x0, procedure=0x0) at sql_select.cc:13501
#20 0x08314cfa in JOIN::exec (this=0xae666ac0) at sql_select.cc:2482
#21 0x08315516 in mysql_select (thd=0xa03cf78, rref_pointer_array=0xa03ea18, tables=0xae6140f0, wild_num=0, fields=..., conds=0xae632a88, og_num=0,
order=0x0, group=0x0, having=0x0, proc_param=0x0, select_options=2147764736, result=0xae632c00, unit=0xa03e678, select_lex=0xa03e914)
at sql_select.cc:2701
#22 0x0830dd73 in handle_select (thd=0xa03cf78, lex=0xa03e61c, result=0xae632c00, setup_tables_done_option=0) at sql_select.cc:282
#23 0x082aa720 in execute_sqlcom_select (thd=0xa03cf78, all_tables=0xae6140f0) at sql_parse.cc:5094
#24 0x082a156a in mysql_execute_command (thd=0xa03cf78) at sql_parse.cc:2239
#25 0x082accc3 in mysql_parse (thd=0xa03cf78,
rawbuf=0xae612eb0 "SELECT COLUMN_DELETE( COLUMN_ADD( `col_blob_not_null_key` , 9 , COLUMN_GET( `col_mediumblob` , 102 AS DATE ) ) , 1 ) FROM `table10_aria_int_autoinc` WHERE COLUMN_CREATE( 159 , NULL AS CHAR , 0 , COLU"..., length=1243, found_semicolon=0xae9a0228) at sql_parse.cc:6094
#26 0x0829f1f3 in dispatch_command (command=COM_QUERY, thd=0xa03cf78, packet=0xa097b89 "", packet_length=1243) at sql_parse.cc:1215
#27 0x0829e651 in do_command (thd=0xa03cf78) at sql_parse.cc:904
#28 0x0829b704 in handle_one_connection (arg=0xa03cf78) at sql_connect.cc:1154
#29 0x00821919 in start_thread () from /lib/libpthread.so.0
#30 0x0076acce in clone () from /lib/libc.so.6

test case will be attached shortly. Unfortunately, automatic simplification is not available.