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

[Andreas Rheinhardt]

lance.lmwang at gmail.com:
> 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) {

No, don't finalize the AVBPrint -- this will make an allocation even if
the string fits into the internal buffer of the AVBPrint. Instead simply
use buf.str directly for dashenc_delete_file().

- Andreas

> +        av_log(s, AV_LOG_WARNING, "Out of memory for filename\n");
> +        return AVERROR(ENOMEM);
>      }
>  
> -    memcpy(filename + dirname_len, file, file_len + 1); // include the terminating zero
>      dashenc_delete_file(s, filename);
>  
> +    av_freep(&filename);
>      return 0;
>  }
>  
>