[FFmpeg-devel] [FFmpeg-cvslog] lavf/url: rewrite ff_make_absolute_url() using ff_url_decompose().

[Marton Balint]

On Wed, 12 Aug 2020, Alexander Strasser wrote:

> Hi all!
>
> On 2020-08-12 14:53 +0000, Nicolas George wrote:
>> ffmpeg | branch: master | Nicolas George <george at nsup.org> | Thu Jul 30 00:02:10 2020 +0200| [1201687da268c11459891a80ca1972aeaca8db88] | committer: Nicolas George
>>
>> lavf/url: rewrite ff_make_absolute_url() using ff_url_decompose().
>>
>> Also add and update some tests.
>>
>> Change the semantic a little, because for filesytem paths
>> symlinks complicate things.
>> See the comments in the code for detail.
>>
>> Fix trac tickets #8813 and 8814.
>>
>> > http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=1201687da268c11459891a80ca1972aeaca8db88
>> ---
>>
>>  libavformat/tests/url.c |  60 ++++++++++-
>>  libavformat/url.c       | 261 ++++++++++++++++++++++++------------------------
>>  libavformat/url.h       |   4 +-
>>  tests/ref/fate/url      |  54 +++++++++-
>>  4 files changed, 245 insertions(+), 134 deletions(-)
>>
> [...]
>> +
>> +    /* This is tricky.
>> +       For HTTP, http://server/site/page + ../media/file
>> +       should resolve into http://server/media/file
>> +       but for filesystem access, dir/playlist + ../media/file
>> +       should resolve into dir/../media/file
>> +       because dir could be a symlink, and .. points to
>> +       the actual parent of the target directory.
>> +
>> +       We'll consider that URLs with an actual scheme and authority,
>> +       i.e. starting with scheme://, need parent dir simplification,
>> +       while bare paths or pseudo-URLs starting with proto: without
>> +       the double slash do not.
>> +
>> +       For real URLs, the processing is similar to the algorithm described
>> +       here:
>> +       https://tools.ietf.org/html/rfc3986#section-5
>> +     */
>
> Stupid question: Why do we transform relative URLs at all?
>
> Isn't it normally supposed to work for HTTP on the server-side too?
>
> Many clients seem to do it. Just curious why...

The RFC requires you to do it:

https://tools.ietf.org/html/rfc3986#section-5.2.4

Regards,
Marton