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Re: [PATCH 1/3] line-log: free diff queue when processing non-merge commits

From
Taylor Blau <me@ttaylorr.com>
Date
Nov 8, 2022, 02:14 UTC
Message-ID
<Y2m7gielFOvTYbvi@nand.local>
In-Reply-To
<20221107155721.GB1951@szeder.dev>
On Mon, Nov 07, 2022 at 04:57:21PM +0100, SZEDER Gábor wrote:
Show 28 quoted lines
> On Mon, Nov 07, 2022 at 04:29:39PM +0100, Ævar Arnfjörð Bjarmason wrote:
> >
> > On Mon, Nov 07 2022, SZEDER Gábor wrote:
> >
> > > On Wed, Nov 02, 2022 at 08:20:21PM -0400, Taylor Blau wrote:
> > >> > +void diff_free_queue(struct diff_queue_struct *q)
> > >> > +{
> > >> > +	for (int i = 0; i < q->nr; i++)
> > >> > +		diff_free_filepair(q->queue[i]);
> > >> > +	free(q->queue);
> > >> > +}
> > >>
> > >> Though I wonder, should diff_free_queue() be a noop when q is NULL? The
> > >> caller in process_ranges_ordinary_commit() doesn't care, of course,
> > >> since q is always non-NULL there.
> > >>
> > >> But if we're making it part of the diff API, we should probably err on
> > >> the side of flexibility.
> > >
> > > On one hand, strbuf_reset(), string_list_clear(), or strvec_clear()
> > > would all segfault on a NULL strbuf, string_list, or strvec pointer.
> >
> > But the reason we do that is because those APIs will always ensure that
> > the struct is never in an inconsistent state, as opposed to the
> > destructor you're adding here.
>
> Taylor's suggestion quoted above is not about the internal state of
> the diff queue, but about a NULL pointer passed to diff_free_queue().

I think your perspective that strbuf_reset(), string_list_clear(), etc. all segfault on a NULL argument is extremely reasonable. Let's start merging this down.

Thanks, Taylor

Previous: SZEDER GáborNext: SZEDER Gábor
Message 10 of 17 in “Bug report: git -L requires excessive memory.”
  1. man dogOct 29, 2022
  2. SZEDER GáborOct 31, 2022
  3. Taylor BlauOct 31, 2022
  4. 0/3 line-log: plug some memory leaksSZEDER Gábor, Nov 2, 2022
  5. 1/3 line-log: free diff queue when processing non-merge commitsSZEDER Gábor, Nov 2, 2022
  6. Taylor BlauNov 3, 2022
  7. SZEDER GáborNov 7, 2022
  8. Ævar Arnfjörð BjarmasonNov 7, 2022
  9. SZEDER GáborNov 7, 2022
  10. Taylor BlauNov 8, 2022
  11. 2/3 line-log: free the diff queues' arrays when processing merge commitsSZEDER Gábor, Nov 2, 2022
  12. Taylor BlauNov 3, 2022
  13. 3/3 diff.c: use diff_free_queue()SZEDER Gábor, Nov 2, 2022
  14. Taylor BlauNov 3, 2022
  15. SZEDER GáborNov 7, 2022
  16. Taylor BlauNov 8, 2022
  17. Ævar Arnfjörð BjarmasonNov 3, 2022

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