From: Junio C Hamano <gitster@pobox.com>
Date: Wed, 23 Oct 2019 04:01:00 GMT
Subject: Re: [PATCH 5/5] path.c: don't call the match function without value in trie_find()
Message-ID: <xmqqa79si003.fsf@gitster-ct.c.googlers.com>
In-Reply-To: <20191021205703.GB4348@szeder.dev>

SZEDER Gábor <szeder.dev@gmail.com> writes:

>>   - b9317d55a3 added two new keys to the trie: 'logs/refs/rewritten'
>>     and 'logs/refs/worktree', next to the already existing
>>     'logs/refs/bisect'.  This resulted in a trie node with the path
>>     'logs/refs', which didn't exist before, and which doesn't have a
>
> Oops, I missed the trailing slash, that must be 'logs/refs/'!
>
>>     value attached.  A query for 'logs/refs/' finds this node and then
>>     hits that one callsite of the match function which doesn't check
>>     for the value's existence, and thus invokes the match function
>>     with NULL as value.

Given that the trie is maintained by hand in common_list[], I wonder
if we can mechanically catch errors like the one b9317d55a3 added,
by perhaps having a self-test function that a t/helper/ program
calls to perform consistency check after the "git" gets built.

Thanks.