[FFmpeg-devel] [PATCH v2] avformat/dashenc: remove the arbitrary restrictions for filename

[Andreas Rheinhardt]

Nicolas George:
> lance.lmwang at gmail.com (12020-04-08):
>> From: Limin Wang <lance.lmwang at gmail.com>
>>
>> Signed-off-by: Limin Wang <lance.lmwang at gmail.com>
>> ---
>>  libavformat/dashenc.c | 28 ++++++++++++----------------
>>  1 file changed, 12 insertions(+), 16 deletions(-)
>>
>> diff --git a/libavformat/dashenc.c b/libavformat/dashenc.c
>> index 94d4639..f80f6f2 100644
>> --- a/libavformat/dashenc.c
>> +++ b/libavformat/dashenc.c
>> @@ -1832,28 +1832,24 @@ static void dashenc_delete_file(AVFormatContext *s, char *filename) {
>>  static int dashenc_delete_segment_file(AVFormatContext *s, const char* file)
>>  {
>>      DASHContext *c = s->priv_data;
>> -    size_t dirname_len, file_len;
>> -    char filename[1024];
>> -
>> -    dirname_len = strlen(c->dirname);
>> -    if (dirname_len >= sizeof(filename)) {
>> -        av_log(s, AV_LOG_WARNING, "Cannot delete segments as the directory path is too long: %"PRIu64" characters: %s\n",
>> -            (uint64_t)dirname_len, c->dirname);
>> -        return AVERROR(ENAMETOOLONG);
>> -    }
>> +    char *filename;
>> +    AVBPrint buf;
>>  
>> -    memcpy(filename, c->dirname, dirname_len);
>> +    av_bprint_init(&buf, 0, AV_BPRINT_SIZE_UNLIMITED);
>>  
>> -    file_len = strlen(file);
>> -    if ((dirname_len + file_len) >= sizeof(filename)) {
>> -        av_log(s, AV_LOG_WARNING, "Cannot delete segments as the path is too long: %"PRIu64" characters: %s%s\n",
>> -            (uint64_t)(dirname_len + file_len), c->dirname, file);
>> -        return AVERROR(ENAMETOOLONG);
>> +    av_bprintf(&buf, "%s%s", c->dirname, file);
>> +    if (!av_bprint_is_complete(&buf)) {
>> +        av_bprint_finalize(&buf, NULL);
>> +        return AVERROR(ENOMEM);
>> +    }
> 
>> +    if (av_bprint_finalize(&buf, &filename) < 0) {
>> +        av_log(s, AV_LOG_WARNING, "Out of memory for filename\n");
>> +        return AVERROR(ENOMEM);
> 
> Do not finalize into a variable if the variable does not outlive the
> AVBPrint structure, just use the string directly and finalize to NULL.
> 
You are commenting on an outdated version of this patch (and saying much
the same as I did). Current version is [1].

- Andreas

[1]: https://ffmpeg.org/pipermail/ffmpeg-devel/2020-April/260048.html