[FFmpeg-devel] [PATCH v2] Handle the following type of relative URL correctly:

[Duncan Salerno]

On Tue, Sep 25, 2012 at 8:51 PM, Clément Bœsch <ubitux at gmail.com> wrote:
> On Tue, Sep 25, 2012 at 07:19:32PM +0100, Duncan Salerno wrote:
>> http://a/b + //c/d = http://c/d
>
> Mmh after a though, shouldn't that be http://a/c/d since N * '/' should
> just be interpreted as a '/'.

No - see RFC 3986 5.4.1.

>> http://a/b?c + ?d = http://a/b?d
>> http://a/b?c/d + /e = http://a/e
>>
>> Updated with feedback from Clément Bœsch
>> ---
>>  libavformat/utils.c |   28 +++++++++++++++++++++++-----
>>  1 file changed, 23 insertions(+), 5 deletions(-)
>>
>> diff --git a/libavformat/utils.c b/libavformat/utils.c
>> index e5826c1..d2d57f1 100644
>> --- a/libavformat/utils.c
>> +++ b/libavformat/utils.c
>> @@ -4467,17 +4467,23 @@ int ff_find_stream_index(AVFormatContext *s, int id)
>>  void ff_make_absolute_url(char *buf, int size, const char *base,
>>                            const char *rel)
>>  {
>> -    char *sep;
>> +    char *sep, *path_query;
>>      /* Absolute path, relative to the current server */
>>      if (base && strstr(base, "://") && rel[0] == '/') {
>>          if (base != buf)
>>              av_strlcpy(buf, base, size);
>>          sep = strstr(buf, "://");
>>          if (sep) {
>> -            sep += 3;
>> -            sep = strchr(sep, '/');
>> -            if (sep)
>> -                *sep = '\0';
>> +            /* Take scheme from base url */
>> +            if (rel[1] == '/')
>> +                sep[1] = '\0';
>> +            else {
>> +                /* Take scheme and host from base url */
>> +                sep += 3;
>> +                sep = strchr(sep, '/');
>> +                if (sep)
>> +                    *sep = '\0';
>> +            }
>>          }
>>          av_strlcat(buf, rel, size);
>>          return;
>> @@ -4489,6 +4495,18 @@ void ff_make_absolute_url(char *buf, int size, const char *base,
>>      }
>>      if (base != buf)
>>          av_strlcpy(buf, base, size);
>> +
>> +    /* Strip off any query string from base */
>> +    path_query = strchr(buf, '?');
>> +    if (path_query != NULL)
>> +        *path_query = '\0';
>> +
>> +    /* Is relative path just a new query part? */
>> +    if (rel[0] == '?') {
>> +        av_strlcat(buf, rel, size);
>> +        return;
>> +    }
>> +
>>      /* Remove the file name from the base url */
>>      sep = strrchr(buf, '/');
>>      if (sep)
>
> No more comment from me.
>
> [...]
>
> Note: could be nice to have a bunch of test-cases to run with this
> function.

Agreed. Happy to send a separate patch if you can give me some
pointers on how to add these tests (I'm new to ffmpeg).