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From:   Junio C Hamano <gitster@pobox.com>
To:     Derrick Stolee <stolee@gmail.com>
Cc:     Elijah Newren <newren@gmail.com>,
        Derrick Stolee via GitGitGadget <gitgitgadget@gmail.com>,
        Git Mailing List <git@vger.kernel.org>,
        Derrick Stolee <derrickstolee@github.com>,
        Derrick Stolee <dstolee@microsoft.com>
Subject: Re: [PATCH v3 2/9] cache-tree: simplify verify_cache() prototype
References: <pull.839.v2.git.1611320639.gitgitgadget@gmail.com>
        <pull.839.v3.git.1611431899.gitgitgadget@gmail.com>
        <1b8b56800948339c0e0387555698bdfdc80a19ad.1611431900.git.gitgitgadget@gmail.com>
        <CABPp-BEsoWs5ZEhS0KTHankzc8eUdmpn0uoF7t1ZtN8b2gwvBA@mail.gmail.com>
        <d910be29-ba90-bbe1-fd96-523508b99781@gmail.com>
Date:   Sat, 23 Jan 2021 13:41:22 -0800
In-Reply-To: <d910be29-ba90-bbe1-fd96-523508b99781@gmail.com> (Derrick
        Stolee's message of "Sat, 23 Jan 2021 16:02:22 -0500")
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Derrick Stolee <stolee@gmail.com> writes:

> On 1/23/2021 3:24 PM, Elijah Newren wrote:
>> On Sat, Jan 23, 2021 at 11:58 AM Derrick Stolee via GitGitGadget
>> <gitgitgadget@gmail.com> wrote:
>>> -       for (i = 0; i < entries - 1; i++) {
>>> +       for (i = 0; i + 1 < istate->cache_nr; i++) {
>>>                 /* path/file always comes after path because of the way
>>>                  * the cache is sorted.  Also path can appear only once,
>>>                  * which means conflicting one would immediately follow.
>>>                  */
>>> -               const struct cache_entry *this_ce = cache[i];
>>> -               const struct cache_entry *next_ce = cache[i + 1];
>>> +               const struct cache_entry *this_ce = istate->cache[i];
>>> +               const struct cache_entry *next_ce = istate->cache[i + 1];
>>>                 const char *this_name = this_ce->name;
>>>                 const char *next_name = next_ce->name;
>>>                 int this_len = ce_namelen(this_ce);
>> Makes sense.  Thanks for explaining the i + 1 < istate->cache_nr bit
>> in the commit message; made it easier to read through quickly.  I'm
>> curious if it deserves a comment in the code too, since it does feel
>> slightly unusual.
>
> I would argue that "i + 1 < N" is a more natural way to write this,
> because we use "i + 1" as an index, so we want to ensure the index
> we are about to use is within range. "i < N - 1" is the backwards
> way to write that statement.

Our mails have crossed, I guess.  Comparing i+1 and N is also good.