Ensure tracks with no title do not reach the end of switch case in Set_Subtitle_Dispositions_by_Title #1

The subtitle track 6 made it to the end of the switch case in Set_Subtitle_Dispositions_by_Title with desiredDisposition[6]="undefined"

{
    index:5,
    codec_name:"hdmv_pgs_subtitle",
    codec_long_name:"HDMV Presentation Graphic Stream subtitles",
    codec_type:"subtitle",
    codec_tag_string:"[0][0][0][0]",
    codec_tag:"0x0000",
    r_frame_rate:"0/0",
    avg_frame_rate:"0/0",
    time_base:"1/1000",
    start_pts:0,
    start_time:"0.000000",
    duration_ts:1418976,
    duration:"1418.976000",
    disposition:{
    default:1,
    dub:0,
    original:0,
    comment:0,
    lyrics:0,
    karaoke:0,
    forced:0,
    hearing_impaired:0,
    visual_impaired:0,
    clean_effects:0,
    attached_pic:0,
    timed_thumbnails:0,
    non_diegetic:0,
    captions:0,
    descriptions:0,
    metadata:0,
    dependent:0,
    still_image:0
},
    tags:
    {
        language:"eng",
        title:"Signs & Songs",
        BPS:"3468",
        DURATION:"00:14:41.172000000",
        NUMBER_OF_FRAMES:"46",
        NUMBER_OF_BYTES:"382042",
        _STATISTICS_WRITING_APP:"mkvpropedit v88.0 ('All I Know') 64-bit",
        _STATISTICS_WRITING_DATE_UTC:"2025-03-13 06:16:57",
        _STATISTICS_TAGS:"BPS DURATION NUMBER_OF_FRAMES NUMBER_OF_BYTES"
    }
},
    {
        index:6,
        codec_name:"hdmv_pgs_subtitle",
        codec_long_name:"HDMV Presentation Graphic Stream subtitles",
        codec_type:"subtitle",
        codec_tag_string:"[0][0][0][0]",
        codec_tag:"0x0000",
        r_frame_rate:"0/0",
        avg_frame_rate:"0/0",
        time_base:"1/1000",
        start_pts:0,
        start_time:"0.000000",
        duration_ts:1418976,
        duration:"1418.976000",
        disposition:{
        default:0,
        dub:0,
        original:0,
        comment:0,
        lyrics:0,
        karaoke:0,
        forced:0,
        hearing_impaired:0,
        visual_impaired:0,
        clean_effects:0,
        attached_pic:0,
        timed_thumbnails:0,
        non_diegetic:0,
        captions:0,
        descriptions:0,
        metadata:0,
        dependent:0,
        still_image:0
    },
    tags:
    {
        language:"eng",
        BPS:"40541",
        DURATION:"00:23:27.240000000",
        NUMBER_OF_FRAMES:"754",
        NUMBER_OF_BYTES:"7131467",
        _STATISTICS_WRITING_APP:"mkvpropedit v88.0 ('All I Know') 64-bit",
        _STATISTICS_WRITING_DATE_UTC:"2025-03-13 06:16:57",
        _STATISTICS_TAGS:"BPS DURATION NUMBER_OF_FRAMES NUMBER_OF_BYTES"
    }
}

The subtitle track 6 made it to the end of the switch case in Set_Subtitle_Dispositions_by_Title with desiredDisposition[6]="undefined" ```json { index:5, codec_name:"hdmv_pgs_subtitle", codec_long_name:"HDMV Presentation Graphic Stream subtitles", codec_type:"subtitle", codec_tag_string:"[0][0][0][0]", codec_tag:"0x0000", r_frame_rate:"0/0", avg_frame_rate:"0/0", time_base:"1/1000", start_pts:0, start_time:"0.000000", duration_ts:1418976, duration:"1418.976000", disposition:{ default:1, dub:0, original:0, comment:0, lyrics:0, karaoke:0, forced:0, hearing_impaired:0, visual_impaired:0, clean_effects:0, attached_pic:0, timed_thumbnails:0, non_diegetic:0, captions:0, descriptions:0, metadata:0, dependent:0, still_image:0 }, tags: { language:"eng", title:"Signs & Songs", BPS:"3468", DURATION:"00:14:41.172000000", NUMBER_OF_FRAMES:"46", NUMBER_OF_BYTES:"382042", _STATISTICS_WRITING_APP:"mkvpropedit v88.0 ('All I Know') 64-bit", _STATISTICS_WRITING_DATE_UTC:"2025-03-13 06:16:57", _STATISTICS_TAGS:"BPS DURATION NUMBER_OF_FRAMES NUMBER_OF_BYTES" } }, { index:6, codec_name:"hdmv_pgs_subtitle", codec_long_name:"HDMV Presentation Graphic Stream subtitles", codec_type:"subtitle", codec_tag_string:"[0][0][0][0]", codec_tag:"0x0000", r_frame_rate:"0/0", avg_frame_rate:"0/0", time_base:"1/1000", start_pts:0, start_time:"0.000000", duration_ts:1418976, duration:"1418.976000", disposition:{ default:0, dub:0, original:0, comment:0, lyrics:0, karaoke:0, forced:0, hearing_impaired:0, visual_impaired:0, clean_effects:0, attached_pic:0, timed_thumbnails:0, non_diegetic:0, captions:0, descriptions:0, metadata:0, dependent:0, still_image:0 }, tags: { language:"eng", BPS:"40541", DURATION:"00:23:27.240000000", NUMBER_OF_FRAMES:"754", NUMBER_OF_BYTES:"7131467", _STATISTICS_WRITING_APP:"mkvpropedit v88.0 ('All I Know') 64-bit", _STATISTICS_WRITING_DATE_UTC:"2025-03-13 06:16:57", _STATISTICS_TAGS:"BPS DURATION NUMBER_OF_FRAMES NUMBER_OF_BYTES" } } ```