[FFmpeg-devel] [PATCH] avformat/http: Fix leak when using deprecated option

[Andreas Rheinhardt]

James Almer:
> On 3/6/2021 1:57 PM, Marton Balint wrote:
>>
>>
>> On Sat, 6 Mar 2021, Andreas Rheinhardt wrote:
>>
>>> When the deprecated option "user-agent" was set to something different
>>> than its default value, said option would always precede and overwrite
>>> the ordinary user_agent option (regardless of whether it was explicitly
>>> set) which leads to a leak of the user_agent option (which has a default
>>> value, so the leak happens always).
>>> Fix this by setting the same destination for both options; the last
>>> option applied wins then.
>>
>> I think you should simply remove the old option. AFAIK public options
>> are not considered part of API/ABI, therefore after the deprecation
>> period of at least 2 years they can be removed anytime. I am not sure
>> why a deprecation guard was added for this removal.
> 
> They have historically been removed after a deprecation period. There is
> a AV_OPT_FLAG_DEPRECATED flag for that purpose after all.
> 

If that's the case, I can prepone the removal of a lot of options. Will
immediately prepare patches.

> Also, new options tend to come with a micro version bump.
> 
>>
>> Regards,
>> Marton
>>
>>>
>>> Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt at gmail.com>
>>> ---
>>> libavformat/http.c | 11 +----------
>>> 1 file changed, 1 insertion(+), 10 deletions(-)
>>>
>>> diff --git a/libavformat/http.c b/libavformat/http.c
>>> index c5df1def62..d44bc64f7b 100644
>>> --- a/libavformat/http.c
>>> +++ b/libavformat/http.c
>>> @@ -78,9 +78,6 @@ typedef struct HTTPContext {
>>>     char *http_version;
>>>     char *user_agent;
>>>     char *referer;
>>> -#if FF_API_HTTP_USER_AGENT
>>> -    char *user_agent_deprecated;
>>> -#endif
>>>     char *content_type;
>>>     /* Set if the server correctly handles Connection: close and will
>>> close
>>>      * the connection after feeding us the content. */
>>> @@ -145,7 +142,7 @@ static const AVOption options[] = {
>>>     { "user_agent", "override User-Agent header", OFFSET(user_agent),
>>> AV_OPT_TYPE_STRING, { .str = DEFAULT_USER_AGENT }, 0, 0, D },
>>>     { "referer", "override referer header", OFFSET(referer),
>>> AV_OPT_TYPE_STRING, { .str = NULL }, 0, 0, D },
>>> #if FF_API_HTTP_USER_AGENT
>>> -    { "user-agent", "use the \"user_agent\" option instead",
>>> OFFSET(user_agent_deprecated), AV_OPT_TYPE_STRING, { .str =
>>> DEFAULT_USER_AGENT }, 0, 0, D|AV_OPT_FLAG_DEPRECATED },
>>> +    { "user-agent", "use the \"user_agent\" option instead",
>>> OFFSET(user_agent), AV_OPT_TYPE_STRING, { .str = DEFAULT_USER_AGENT
>>> }, 0, 0, D|AV_OPT_FLAG_DEPRECATED },
>>> #endif
>>>     { "multiple_requests", "use persistent connections",
>>> OFFSET(multiple_requests), AV_OPT_TYPE_BOOL, { .i64 = 0 }, 0, 1, D |
>>> E },
>>>     { "post_data", "set custom HTTP post data", OFFSET(post_data),
>>> AV_OPT_TYPE_BINARY, .flags = D | E },
>>> @@ -1321,12 +1318,6 @@ static int http_connect(URLContext *h, const
>>> char *path, const char *local_path,
>>>         }
>>>     }
>>>
>>> -#if FF_API_HTTP_USER_AGENT
>>> -    if (strcmp(s->user_agent_deprecated, DEFAULT_USER_AGENT)) {
>>> -        s->user_agent = av_strdup(s->user_agent_deprecated);
>>> -    }
>>> -#endif
>>> -
>>>     av_bprintf(&request, "%s ", method);
>>>     bprint_escaped_path(&request, path);
>>>     av_bprintf(&request, " HTTP/1.1\r\n");
>>> -- 
>>> 2.27.0
>>>