On 9/1/2020 9:51 AM, Jeff King wrote:
> On Tue, Sep 01, 2020 at 09:04:36AM -0400, Derrick Stolee wrote:
>> Adding an `if (!size) {free(ptr); return NULL;}` block was what I
>> expected. Was that chosen just so we can rely more on the system
>> realloc(), or is there a performance implication that I'm not
>> seeing?
>
> I went back and forth on whether to do that or not. This case should
> basically never happen, so I like both the performance and readability
> of only triggering it when realloc() returns NULL. But it would get rid
> of the hand-waving above, and I doubt the performance is measurable.
>
> If we do handle it up-front, then I think we'd actually want:
>
> if (!size) {
> free(ptr);
> return xmalloc(0);
> }
>
> (i.e., to never return NULL for consistency with xmalloc() and
> xcalloc()).
Good point. In that sense, your change makes a lot more
sense for staying consistent without strangeness like xmalloc(0).
>>> @@ -120,7 +120,7 @@ void *xrealloc(void *ptr, size_t size)
>>> memory_limit_check(size, 0);
>>> ret = realloc(ptr, size);
>>> if (!ret && !size)
>>> - ret = realloc(ptr, 1);
>>> + ret = realloc(ret, 1);
>>
>> I appreciate all the additional context for such a small change.
>
> Somebody's got to complete with you for ratio of commit message to diff
> lines. :)
Pretty sure I have a long way to match, but it is important to
have goals.
-Stolee
