avcodec/parser: reset indexes on realloc failure

Fixes Ticket2982

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
AVCodecParserContext *av_parser_init(int codec_id)
{
    AVCodecParserContext *s = NULL;
    AVCodecParser *parser;
    int ret;

    if(codec_id == AV_CODEC_ID_NONE)
        return NULL;

    for(parser = av_first_parser; parser != NULL; parser = parser->next) {
        if (parser->codec_ids[0] == codec_id ||
            parser->codec_ids[1] == codec_id ||
            parser->codec_ids[2] == codec_id ||
            parser->codec_ids[3] == codec_id ||
            parser->codec_ids[4] == codec_id)
            goto found;
    }
    return NULL;
 found:
    s = av_mallocz(sizeof(AVCodecParserContext));
    if (!s)
        goto err_out;
    s->parser = parser;
    s->priv_data = av_mallocz(parser->priv_data_size);
    if (!s->priv_data)
        goto err_out;
    s->fetch_timestamp=1;
    s->pict_type = AV_PICTURE_TYPE_I;
    if (parser->parser_init) {
        ret = parser->parser_init(s);
        if (ret != 0)
            goto err_out;
    }
    s->key_frame = -1;
    s->convergence_duration = 0;
    s->dts_sync_point       = INT_MIN;
    s->dts_ref_dts_delta    = INT_MIN;
    s->pts_dts_delta        = INT_MIN;
    return s;

err_out:
    if (s)
        av_freep(&s->priv_data);
    av_free(s);
    return NULL;
}

AVCodecParserContext *av_parser_init(int codec_id)
{
    AVCodecParserContext *s = NULL;
    AVCodecParser *parser;
    int ret;

    if(codec_id == AV_CODEC_ID_NONE)
        return NULL;

    for(parser = av_first_parser; parser != NULL; parser = parser->next) {
        if (parser->codec_ids[0] == codec_id ||
            parser->codec_ids[1] == codec_id ||
            parser->codec_ids[2] == codec_id ||
            parser->codec_ids[3] == codec_id ||
            parser->codec_ids[4] == codec_id)
            goto found;
    }
    return NULL;
 found:
    s = av_mallocz(sizeof(AVCodecParserContext));
    if (!s)
        goto err_out;
    s->parser = parser;
    s->priv_data = av_mallocz(parser->priv_data_size);
    if (!s->priv_data)
        goto err_out;
    s->fetch_timestamp=1;
    s->pict_type = AV_PICTURE_TYPE_I;
    if (parser->parser_init) {
        ret = parser->parser_init(s);
        if (ret != 0)
            goto err_out;
    }
    s->key_frame = -1;
    s->convergence_duration = 0;
    s->dts_sync_point       = INT_MIN;
    s->dts_ref_dts_delta    = INT_MIN;
    s->pts_dts_delta        = INT_MIN;
    return s;

err_out:
    if (s)
        av_freep(&s->priv_data);
    av_free(s);
    return NULL;
}
