[FFmpeg-devel] [FFmpeg-cvslog] cbs_mpeg2: Fix type for marker_bit reading

[Carl Eugen Hoyos]

2017-10-25 0:29 GMT+02:00 Mark Thompson <sw at jkqxz.net>:
> On 24/10/17 23:14, Carl Eugen Hoyos wrote:
>> 2017-10-25 0:09 GMT+02:00 Mark Thompson <git at videolan.org>:
>>> ffmpeg | branch: master | Mark Thompson <sw at jkqxz.net> | Tue Oct 24 22:56:48 2017 +0100| [5b2c71bb94d7cab23ee81b5c29388f5fadbcaf22] | committer: Mark Thompson
>>>
>>> cbs_mpeg2: Fix type for marker_bit reading
>>>
>>>> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=5b2c71bb94d7cab23ee81b5c29388f5fadbcaf22
>>> ---
>>>
>>>  libavcodec/cbs_mpeg2.c | 2 +-
>>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>>
>>> diff --git a/libavcodec/cbs_mpeg2.c b/libavcodec/cbs_mpeg2.c
>>> index d137762227..0cac29733e 100644
>>> --- a/libavcodec/cbs_mpeg2.c
>>> +++ b/libavcodec/cbs_mpeg2.c
>>> @@ -54,7 +54,7 @@
>>>          xui(width, name, current->name)
>>>
>>>  #define marker_bit() do { \
>>> -        av_unused int one = 1; \
>>> +        av_unused uint32_t one; \
>>>          CHECK(ff_cbs_read_unsigned(ctx, rw, 1, "marker_bit", &one, 1, 1)); \
>>
>> The commit message doesn't match the change / is this defined behaviour?
>
> It's only written and never read, so the initialisation isn't doing anything.

I asked because I believe it was reported once that a static analyzer protested
on passing uninitialized stuff - that was never going to be used - as
a parameter.
(But that may have been an uninitialized variable that was never used,
not a pointer.)

Thank you, Carl Eugen