Server crashes in in prep_alter_part_table on 2nd execution of PS

--source include/have_partition.inc

CREATE TABLE t1 (a INT) ENGINE=MyISAM PARTITION BY RANGE(a) (PARTITION p1 VALUES LESS THAN (0));

ALTER TABLE t1 ADD PARTITION (PARTITION p2 VALUES LESS THAN (1));

PREPARE stmt FROM 'ALTER TABLE t1 ADD PARTITION IF NOT EXISTS (PARTITION p2 VALUES LESS THAN (2))';

EXECUTE stmt;

EXECUTE stmt;

# Cleanup

DROP TABLE t1;

#3  <signal handler called>

#4  0x00000000009aaa78 in prep_alter_part_table (thd=0x7ffba8aa2070, table=0x7ffba709e470, alter_info=0x7ffbb0b82830, create_info=0x7ffbb0b828c0, alter_ctx=0x7ffbb0b81c20, partition_changed=0x7ffbb0b8271b, fast_alter_table=0x7ffbb0b8271a) at /data/src/10.0/sql/sql_partition.cc:4857

#5  0x0000000000703f27 in mysql_alter_table (thd=0x7ffba8aa2070, new_db=0x7ffba73d2bc8 "test", new_name=0x0, create_info=0x7ffbb0b828c0, table_list=0x7ffba73d25e8, alter_info=0x7ffbb0b82830, order_num=0, order=0x0, ignore=false) at /data/src/10.0/sql/sql_table.cc:8607

#6  0x000000000076d365 in Sql_cmd_alter_table::execute (this=0x7ffba73d2fa0, thd=0x7ffba8aa2070) at /data/src/10.0/sql/sql_alter.cc:312

#7  0x000000000065398b in mysql_execute_command (thd=0x7ffba8aa2070) at /data/src/10.0/sql/sql_parse.cc:5114

#8  0x000000000066f1ec in Prepared_statement::execute (this=0x7ffba7127470, expanded_query=0x7ffbb0b83bd0, open_cursor=false) at /data/src/10.0/sql/sql_prepare.cc:3974

#9  0x000000000066e2be in Prepared_statement::execute_loop (this=0x7ffba7127470, expanded_query=0x7ffbb0b83bd0, open_cursor=false, packet=0x0, packet_end=0x0) at /data/src/10.0/sql/sql_prepare.cc:3629

#10 0x000000000066c5ac in mysql_sql_stmt_execute (thd=0x7ffba8aa2070) at /data/src/10.0/sql/sql_prepare.cc:2779

#11 0x000000000064c708 in mysql_execute_command (thd=0x7ffba8aa2070) at /data/src/10.0/sql/sql_parse.cc:2563

#12 0x0000000000656dc2 in mysql_parse (thd=0x7ffba8aa2070, rawbuf=0x7ffba70fa088 "EXECUTE stmt", length=12, parser_state=0x7ffbb0b84640) at /data/src/10.0/sql/sql_parse.cc:6569

#13 0x0000000000649901 in dispatch_command (command=COM_QUERY, thd=0x7ffba8aa2070, packet=0x7ffba9fe5071 "EXECUTE stmt", packet_length=12) at /data/src/10.0/sql/sql_parse.cc:1296

#14 0x0000000000648c01 in do_command (thd=0x7ffba8aa2070) at /data/src/10.0/sql/sql_parse.cc:999

#15 0x0000000000768ab8 in do_handle_one_connection (thd_arg=0x7ffba8aa2070) at /data/src/10.0/sql/sql_connect.cc:1377

#16 0x000000000076882a in handle_one_connection (arg=0x7ffba8aa2070) at /data/src/10.0/sql/sql_connect.cc:1292

#17 0x0000000000ac9564 in pfs_spawn_thread (arg=0x7ffba89a2370) at /data/src/10.0/storage/perfschema/pfs.cc:1861

#18 0x00007ffbb07b8494 in start_thread (arg=0x7ffbb0b85700) at pthread_create.c:333

#19 0x00007ffbaeb7193f in clone () from /lib/x86_64-linux-gnu/libc.so.6