mysql_upgrade from MySQL 5.0 crashes in DBUG_ASSERT

Trying to run mysql_upgrade from MySQL 5.0 to Mariadb 5.2 crashes
in DBUG_ASSERT()

Version: '5.2.5-MariaDB-debug' socket: '' port: 0 Source distribution
Assertion failed: next_chunk <= buff_end, file ..\..\sql\table.cc, line 998
110130 0:58:06 [ERROR] mysqld got exception 0x80000003 ;
This could be because you hit a bug. It is also possible that this binary
or one of the libraries it was linked against is corrupt, improperly built,
or misconfigured. This error can also be caused by malfunctioning hardware.
We will try our best to scrape up some info that will hopefully help diagnose
the problem, but since we have already crashed, something is definitely wrong
and this may fail.

key_buffer_size=0
read_buffer_size=65536
max_used_connections=1
max_threads=102
threads_connected=1
It is possible that mysqld could use up to
key_buffer_size + (read_buffer_size + sort_buffer_size)*max_threads = 33426 K
bytes of memory
Hope that's ok; if not, decrease some variables in the equation.

thd: 0x16850f38
Attempting backtrace. You can use the following information to find out
where mysqld died. If you see no messages after this, something went
terribly wrong...
002CB9A3 mysqld.exe!my_sigabrt_handler()[mysqld.cc:2203]
00298DA9 mysqld.exe!raise()[winsig.c:586]
0029D4D6 mysqld.exe!abort()[abort.c:74]
008A6847 mysqld.exe!_wassert()[assert.c:336]
0044A45E mysqld.exe!open_binary_frm()[table.cc:998]
00449579 mysqld.exe!open_table_def()[table.cc:651]
003ABBF2 mysqld.exe!get_table_share()[sql_base.cc:383]
003B4166 mysqld.exe!get_table_share_with_create()[sql_base.cc:462]
003B39EE mysqld.exe!open_unireg_entry()[sql_base.cc:3913]
003B1697 mysqld.exe!open_table()[sql_base.cc:2954]
003B4DD8 mysqld.exe!open_tables()[sql_base.cc:4676]
003B5F54 mysqld.exe!open_and_lock_tables_derived()[sql_base.cc:5094]
003037A2 mysqld.exe!simple_open_n_lock_tables()[mysql_priv.h:1564]
003B59A2 mysqld.exe!open_n_lock_single_table()[sql_base.cc:4972]
00400C8E mysqld.exe!mysql_alter_table()[sql_table.cc:6772]
004322BC mysqld.exe!mysql_execute_command()[sql_parse.cc:2963]
0043AEE2 mysqld.exe!mysql_parse()[sql_parse.cc:6128]
0042EA2A mysqld.exe!dispatch_command()[sql_parse.cc:1209]
0042E274 mysqld.exe!do_command()[sql_parse.cc:903]
0032C41B mysqld.exe!handle_one_connection()[sql_connect.cc:1154]
008D925D mysqld.exe!pthread_start()[my_winthread.c:87]
008AAD23 mysqld.exe!_callthreadstart()[thread.c:259]
008AACB9 mysqld.exe!_threadstart()[thread.c:243]
75A63677 kernel32.dll!BaseThreadInitThunk()
77AC9D42 ntdll.dll!RtlInitializeExceptionChain()
77AC9D15 ntdll.dll!RtlInitializeExceptionChain()
Trying to get some variables.
Some pointers may be invalid and cause the dump to abort...
thd->query at 16869E20=ALTER TABLE procs_priv
   ENGINE=MyISAM,
   CONVERT TO CHARACTER SET utf8 COLLATE utf8_bin
thd->thread_id=4
thd->killed=NOT_KILLED

Subsequent attempt to start fails with the same assertion but in different code path:

thd: 0x1e28b000
Attempting backtrace. You can use the following information to find out
where mysqld died. If you see no messages after this, something went
terribly wrong...
00CAB9A3 mysqld.exe!my_sigabrt_handler()[mysqld.cc:2203]
00C78DA9 mysqld.exe!raise()[winsig.c:586]
00C7D4D6 mysqld.exe!abort()[abort.c:74]
01286847 mysqld.exe!_wassert()[assert.c:336]
00E2A45E mysqld.exe!open_binary_frm()[table.cc:998]
00E29579 mysqld.exe!open_table_def()[table.cc:651]
00D8BBF2 mysqld.exe!get_table_share()[sql_base.cc:383]
00D94166 mysqld.exe!get_table_share_with_create()[sql_base.cc:462]
00D939EE mysqld.exe!open_unireg_entry()[sql_base.cc:3913]
00D91697 mysqld.exe!open_table()[sql_base.cc:2954]
00D9F13D mysqld.exe!open_system_tables_for_read()[sql_base.cc:9186]
00DCCFF5 mysqld.exe!my_tz_init()[tztime.cc:1645]
00CAC869 mysqld.exe!win_main()[mysqld.cc:4695]
00CAF841 mysqld.exe!mysql_service()[mysqld.cc:4847]
0128AD23 mysqld.exe!_callthreadstart()[thread.c:259]
0128ACB9 mysqld.exe!_threadstart()[thread.c:243]
75A63677 kernel32.dll!BaseThreadInitThunk()
77AC9D42 ntdll.dll!RtlInitializeExceptionChain()
77AC9D15 ntdll.dll!RtlInitializeExceptionChain()