m3u playlists not loading properly

[cmorgenstern]

• [X] I have checked the FAQ for answers.
• [X] I have checked the Changelog that the issue is not already fixed.
• [X] I believe this issue is a bug, and not a general technical issue, question or feature requests that can be discussed on the forum.

Describe the bug Local tracks in playlists are not correctly linked to library items. Loading a newly saved M3U playlist also produces the same result. Similar to #1430, but still broken

To Reproduce

1. Open Strawberry
2. Open an M3U playlist containing local track

Expected: Playlist loads with the entries linked to tracks in the library

Actual: Playlist entries are not linked and cannot be played.

1. Open Strawberry
2. Create a new playlist and and add some tracks
3. Save the playlist (.m3u) and close it
4. Load the saved playlist

Expected: Playlist loads with the entries linked to tracks in the library

Actual: Playlist entries are not linked and cannot be played.

Screenshots:

System Information:

• Operating system: Arch Linux
• Strawberry Version: 1.0.23.r176.g6e90e72b-1

Additional context Command line output:

...
22:22:21.627 DEBUG MainWindow:870                   Creating playing widget
22:22:21.659 DEBUG MainWindow:917                   Loading settings
22:22:21.701 DEBUG MainWindow:1082                  Started QThread(0x5eebbb486170)
22:22:26.632 WARN  unknown                          The requested buffer size is too big, ignoring 
22:22:28.286 DEBUG SongLoader:231                   Loading local file "/home/username/Music/playlists/clear.m3u"
22:22:28.287 DEBUG SongLoader:294                   Parsing using "M3U"
22:22:28.289 DEBUG _MessageReplyBase:31             Waiting on ID 0
22:22:28.289 DEBUG TagReaderTagLib:237              Reading tags from "../library/Rammstein/Liebe ist für alle da/Haifisch.mp3"
22:22:28.289 INFO  TagReaderTagLib:255              TagLib hasn't been able to read "../library/Rammstein/Liebe ist für alle da/Haifisch.mp3" file
22:22:28.289 DEBUG MessageReply<MessageType>:90     Releasing ID 0 (finished)
22:22:28.289 DEBUG _MessageReplyBase:33             Acquired ID 0
22:22:28.290 DEBUG _MessageReplyBase:31             Waiting on ID 1
22:22:28.290 DEBUG TagReaderTagLib:237              Reading tags from "../library/Rammstein/Reise, Reise/Los.mp3"
22:22:28.290 INFO  TagReaderTagLib:255              TagLib hasn't been able to read "../library/Rammstein/Reise, Reise/Los.mp3" file
22:22:28.290 DEBUG MessageReply<MessageType>:90     Releasing ID 1 (finished)
22:22:28.290 DEBUG _MessageReplyBase:33             Acquired ID 1
...

[jonaski]

I mistakenly removed the absolute path part in 2953f9e, hopefully fixed now, but will do more testing when I get the time.

[cmorgenstern]

Built and compiled with the changes, appears to be fixed - thanks.