Bug #160 mysamchk crash
Submitted: 18 Mar 2003 10:32 Modified: 7 Jul 2003 4:34
Reporter: Alexander Keremidarski Email Updates:
Status: Won't fix Impact on me:
None 
Category:MySQL Server: Command-line Clients Severity:S3 (Non-critical)
Version:4.0 OS:
Assigned to: Sergei Golubchik CPU Architecture:Any

[18 Mar 2003 10:32] Alexander Keremidarski
Description:
With particular broken table myisamchk crashes with:

bt
#0  0x0805f6a1 in decode_bytes (rec=0x4339a000, bit_buff=0x80bac1c, to=0x4339a000 "", end=0x4365f6b3 "") at mi_packrec.c:885
#1  0x0805f533 in uf_blob (rec=0x80b8b20, bit_buff=0x80bac1c, to=0x408371f0 "li
#2  0x0805e8ed in _mi_pack_rec_unpack (info=0x80babe0, to=0x408371f0 "li
#3  0x080684bf in chk_data_link (param=0x80b6360, info=0x80babe0, extend=0) at mi_check.c:937
#4  0x080516e9 in myisamchk (param=0x80b6360, filename=0xbffffbb6 "contig_data") at myisamchk.c:1019
#5  0x08050165 in main (argc=0, argv=0x80b8478) at myisamchk.c:101
#6  0x420158d4 in __libc_start_main () from /lib/i686/libc.so.6

/myisam/mi_packrec.c:885

static void decode_bytes(MI_COLUMNDEF *rec,MI_BIT_BUFF *bit_buff,uchar *to,
    			 uchar *end)

...

    if (low_byte & IS_CHAR)
    {
      *to++ = (low_byte & 255);		/* Found char in quick table */
       ^^^^^^^^^^^^^^^^^

How to repeat:
get test case table from 
ftp://web.mysql.com://pub/archive/secret/contig_data.tar.bz2

and run myisamchk contig_table
[19 Mar 2003 10:36] Michael Widenius
This is a crashed table that is changed by some other program for MySQL.

As this is extremely unlikely to happen in real life, we will not fix this in the near future.