Comment 2 for bug 917942

Current Percona Server 5.1 debug build crashes on percona_innodb_fake_changes_bugs2.test this way:

121011 18:50:37 InnoDB: Assertion failure in thread 140724337829632 in file ./include/mtr0log.ic line 192
InnoDB: Failing assertion: mtr_memo_contains_page(mtr, ptr, 2)

Thread 1 (Thread 0x7f5068343700 (LWP 21949)):
#0 __pthread_kill (threadid=<optimized out>, signo=<optimized out>) at ../nptl/sysdeps/unix/sysv/linux/pthread_kill.c:63
#1 0x0000000000a70b3d in my_write_core (sig=6) at stacktrace.c:437
#2 0x00000000007c580e in handle_fatal_signal (sig=6) at signal_handler.cc:249
#3 <signal handler called>
#4 0x00007f50693da445 in __GI_raise (sig=<optimized out>) at ../nptl/sysdeps/unix/sysv/linux/raise.c:64
#5 0x00007f50693ddbab in __GI_abort () at abort.c:91
#6 0x00000000008efd57 in mlog_write_initial_log_record_fast (ptr=0x7f5063b64000 "", type=51 '3', log_ptr=0x7f5068340810 "\a", mtr=0x7f50683405b0) at ./include/mtr0log.ic:192
#7 0x0000000000904369 in page_zip_compress_write_log (page_zip=0x7f505bfd7188, page=0x7f5063b64000 "", index=0x7f5038034198, mtr=0x7f50683405b0) at page/page0zip.c:351
#8 0x0000000000906b79 in page_zip_compress (page_zip=0x7f505bfd7188, page=0x7f5063b64000 "", index=0x7f5038034198, mtr=0x7f50683405b0) at page/page0zip.c:1445
#9 0x0000000000975bd2 in btr_cur_update_alloc_zip (page_zip=0x7f505bfd7188, block=0x7f505bfd7178, index=0x7f5038034198, length=6528, create=1, mtr=0x7f50683405b0) at btr/btr0cur.c:1781
#10 0x00000000009765cc in btr_cur_optimistic_update (flags=2, cursor=0x7f50380158b8, update=0x7f50380136f0, cmpl_info=1, thr=0x7f50380138f0, mtr=0x7f50683405b0) at btr/btr0cur.c:2062
#11 0x000000000093bafc in row_upd_clust_rec (node=0x7f50380135e8, index=0x7f5038034198, thr=0x7f50380138f0, mtr=0x7f50683405b0) at row/row0upd.c:1970
#12 0x000000000093c468 in row_upd_clust_step (node=0x7f50380135e8, thr=0x7f50380138f0) at row/row0upd.c:2251
#13 0x000000000093c6b4 in row_upd (node=0x7f50380135e8, thr=0x7f50380138f0) at row/row0upd.c:2331
#14 0x000000000093c9ac in row_upd_step (thr=0x7f50380138f0) at row/row0upd.c:2464
#15 0x000000000092656d in row_update_for_mysql (mysql_rec=0x7f5038036228 "\244", <incomplete sequence \310>, prebuilt=0x7f503800add8) at row/row0mysql.c:1416
#16 0x00000000008b8077 in ha_innobase::update_row (this=0x7f5038035cf8, old_row=0x7f5038036228 "\244", <incomplete sequence \310>, new_row=0x7f5038036148 "\244", <incomplete sequence \310>) at handler/ha_innodb.cc:5668
#17 0x00000000007aff6c in handler::ha_update_row (this=0x7f5038035cf8, old_data=0x7f5038036228 "\244", <incomplete sequence \310>, new_data=0x7f5038036148 "\244", <incomplete sequence \310>) at handler.cc:4837
#18 0x0000000000709812 in write_record (thd=0x2de19d8, table=0x7f5038031e08, info=0x7f5068340de0) at sql_insert.cc:1520
#19 0x0000000000707c02 in mysql_insert (thd=0x2de19d8, table_list=0x7f5038004aa8, fields=..., values_list=..., update_fields=..., update_values=..., duplic=DUP_UPDATE, ignore=false) at sql_insert.cc:863
#20 0x0000000000668503 in mysql_execute_command (thd=0x2de19d8) at sql_parse.cc:3436
#21 0x0000000000671085 in mysql_parse (thd=0x2de19d8, rawbuf=0x7f5038004908 "insert into t1 values (200, \"foo\", lpad(\"a\", ((200 * 100) + 4500) mod 9000, \"b\")) on duplicate key update t = values(t)", length=119, found_semicolon=0x7f5068342900) at sql_parse.cc:6302
#22 0x0000000000662cce in dispatch_command (command=COM_QUERY, thd=0x2de19d8, packet=0x2e34c59 "insert into t1 values (200, \"foo\", lpad(\"a\", ((200 * 100) + 4500) mod 9000, \"b\")) on duplicate key update t = values(t)", packet_length=119) at sql_parse.cc:1298
#23 0x0000000000661b73 in do_command (thd=0x2de19d8) at sql_parse.cc:908
#24 0x000000000065fca0 in handle_one_connection (arg=0x2de19d8) at sql_connect.cc:2056
#25 0x00007f506a2c0e9a in start_thread (arg=0x7f5068343700) at pthread_create.c:308
#26 0x00007f5069497dbd in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:112
#27 0x0000000000000000 in ?? ()