Bug #51893 crash with certain characters given to load_file function on windows

Description:
5.1.44 release binary detects corruption here and crashes:

mysqld.exe!__crt_debugger_hook
mysqld.exe!__report_gsfailure
mysqld.exe!normalize_dirname
mysqld.exe!unpack_dirname
mysqld.exe!fn_format
mysqld.exe!Item_load_file::val_str
mysqld.exe!Item::send
mysqld.exe!select_send::send_data
mysqld.exe!JOIN::exec
mysqld.exe!mysql_select
mysqld.exe!handle_select
mysqld.exe!execute_sqlcom_select
mysqld.exe!mysql_execute_command
mysqld.exe!mysql_parse
mysqld.exe!dispatch_command
mysqld.exe!do_command
mysqld.exe!handle_one_connection
mysqld.exe!pthread_start
mysqld.exe!_callthreadstart
mysqld.exe!_threadstart

Windows debug binaries print safemalloc errors in the logs:
Error:Run-Time Check Failure #2 - Stack around the variable 'buff' was corrupted. At g:\mysql-5.1.44-winbuild\mysql-advanced-gpl-debug-5.1.44-build\mysys\mf_pack.c:321

How to repeat:
\o/

windows testcase.

Attachment: bug51893_testcase.sql (application/octet-stream, text), 1.60 KiB.

C:\DBS>cat 5.1\data\tikal.err
100309 18:34:28 [Note] Plugin 'FEDERATED' is disabled.
100309 18:34:28 [Note] Event Scheduler: Loaded 0 events
100309 18:34:28 [Note] C:\DBS\5.1\bin\mysqld: ready for connections.
Version: '5.1.46-Win X64-debug-log'  socket: ''  port: 3306  Source distribution
Error:Run-Time Check Failure #2 - Stack around the variable 'buff' was corrupted. At :0

Repeatable on 5.1.32:

100309 19:14:05 [Note] bin\mysqld-debug: ready for connections.
Version: '5.1.32-community-debug'  socket: ''  port: 3306  MySQL Community Server - Debug (GPL)
Error:Run-Time Check Failure #2 - Stack around the variable 'buff' was corrupted. At :0

A patch for this bug has been committed. After review, it may
be pushed to the relevant source trees for release in the next
version. You can access the patch from:

  http://lists.mysql.com/commits/104096

3412 Georgi Kodinov	2010-03-23
      Bug #51893: crash with certain characters given to load_file 
        function on windows
      
      When making sure that the directory path ends up with a 
      slash/backslash we need to check for the correct length of 
      the buffer and trim at the appropriate location so we don't
      write past the end of the buffer.

Pushed into 5.0.91 (revid:joro@sun.com-20100406075152-flz4btqirl9hly31) (version source revid:joro@sun.com-20100330120350-nts3p251bgmquodi) (merge vers: 5.0.91) (pib:16)

Pushed into 5.1.46 (revid:sergey.glukhov@sun.com-20100405111026-7kz1p8qlzglqgfmu) (version source revid:joro@sun.com-20100330121025-r7wz0k8dlf3b0q0e) (merge vers: 5.1.46) (pib:16)

Noted in 5.0.91, 5.1.46 changelogs.

On Windows, LOAD_FILE() could cause a crash for some path names.

Setting report to Need Merge pending push into Celosia.

Pushed into mysql-next-mr (revid:alik@sun.com-20100524190136-egaq7e8zgkwb9aqi) (version source revid:alik@sun.com-20100422150750-vp0n37kp9ywq5ghf) (pib:16)

Pushed into 6.0.14-alpha (revid:alik@sun.com-20100524190941-nuudpx60if25wsvx) (version source revid:alik@sun.com-20100422150658-fkhgnwwkyugtxrmu) (merge vers: 6.0.14-alpha) (pib:16)

Pushed into 5.5.5-m3 (revid:alik@sun.com-20100524185725-c8k5q7v60i5nix3t) (version source revid:alexey.kopytov@sun.com-20100403173551-52r97erqowlqwkon) (merge vers: 5.5.4-m3) (pib:16)

Noted in 5.5.5, 6.0.14 changelogs.

Pushed into 5.1.47-ndb-7.0.16 (revid:martin.skold@mysql.com-20100617114014-bva0dy24yyd67697) (version source revid:vasil.dimov@oracle.com-20100331130613-8ja7n0vh36a80457) (merge vers: 5.1.46) (pib:16)

Pushed into 5.1.47-ndb-6.2.19 (revid:martin.skold@mysql.com-20100617115448-idrbic6gbki37h1c) (version source revid:martin.skold@mysql.com-20100609211156-tsac5qhw951miwtt) (merge vers: 5.1.46-ndb-6.2.19) (pib:16)

Pushed into 5.1.47-ndb-6.3.35 (revid:martin.skold@mysql.com-20100617114611-61aqbb52j752y116) (version source revid:vasil.dimov@oracle.com-20100331130613-8ja7n0vh36a80457) (merge vers: 5.1.46) (pib:16)