Re: Delimit query-cache key to prevent collisions

> I have reviewed the patch(009-encode-key-delimiter) from Emond.
> It has also passed all regression tests.
>
> encode_key() constructs the cache key using md5(user || query || database) without delimiters.
> This allows different sessions to produce identical keys
> (e.g., "admin" + "Q" + "testdb" and "adm" + "Q" + "intestdb"),
> leading to data leakage between users/databases.
>
> Changes:
> Explicit Delimiters: Insert NUL bytes between the user, query, and database fields in the buffer.
> Hash Full Range: Updated the hash function to process the entire byte range (including NUL separators)
> instead of stopping at the first NUL byte.
>
> Thank you, Emond.

I have looked into this. The patch looks good to me. Also I ran some
of query cache related regression tests on master branch.

testing 006.memqcache...ok.
testing 007.memqcache-memcached...ok.
testing 008.dbredirect...ok.
testing 120.memory_leak_extended_memqcache...ok.
testing 124.bug700_memqcache_segfault...ok.

They all passed here.

Regards,
--
Tatsuo Ishii
SRA OSS K.K.
English: http://www.sraoss.co.jp/index_en/
Japanese:http://www.sraoss.co.jp