[FFmpeg-devel] [PATCH] all: Don't set AVClass.item_name to its default value

Anton Khirnov anton at khirnov.net
Mon Dec 25 12:21:00 EET 2023


Quoting Zhao Zhili (2023-12-25 10:27:59)
> 
> 
> > On Dec 25, 2023, at 16:38, Anton Khirnov <anton at khirnov.net> wrote:
> > 
> > Quoting Kacper Michajlow (2023-12-24 11:41:52)
> >> On Fri, 22 Dec 2023 at 14:57, Anton Khirnov <anton at khirnov.net> wrote:
> >>> 
> >>> Quoting Andreas Rheinhardt (2023-12-22 14:48:45)
> >>>> Avoids relocations.
> >>>> 
> >>>> Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt at outlook.com>
> >>>> ---
> >>> 
> >>> Maybe mention that it's not needed after
> >>> acf63d5350adeae551d412db699f8ca03f7e76b9.
> >> 
> >> This is not the only user of this API, no?
> >> 
> >> I have a question for my own curiosity. This is ABI (and API) breaking
> >> change,
> > 
> > It is not. This item was not guaranteed to be set, which was actually
> > the reason I wrote the patch that this one refers to.
> 
> There is no problem to relax a restriction inside libavutil. However, since there is
> no explicit documentation on whether item_name can be null or not, user may make
> incorrect assumptions and depend on item_name not being null. I don’t think break
> user’s code suddenly is a good idea, although we can say it’s break since the beginning.

My point is that the restriction never existed. There were always
AVClass instances that did not set that pointer. There were fewer of
them, but they did exist.

-- 
Anton Khirnov


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