Scan stuck due to artist field being too long

[kudev]

I am trying to scan my files. One of these files is an MP3 with an artist field that's around 300 characters.

Expected behavior

The file is scanned without any issues.

Actual behavior

The scan simply hangs indefinitely. Checking the nextcloud logs revealed that the column's length is limited to 256 in the database.

Steps to reproduce the behavior

1. Have a song with an artist field longer than 256 characters
2. Try to scan it

Possible solution (optional)

Basic ideas:

• Remove character limit
• Trim artist
• Handle the error so the user can react

Server configuration

Operating system:
Linux

Web server:
Nginx

Database:
PostgreSQL 9.6.1

PHP version:
7.1.2

ownCloud/Nextcloud version: (see /status.php)
11.0.1.2

Updated from an older ownCloud/Nextcloud or fresh install:
Fresh install

Audio Player version: (see /settings/apps)
1.4.1

Where did you install Audio Player from:
The NextCloud apps page

Are you using external storage, if yes which one: local

Are you using encryption: no

Client configuration

Operating system:
Linux

Browser:
Firefox 51

Logs

ownCloud/Nextcloud log

ownCloud/Nextcloud log (`/data/[owncloud|nextcloud].log`)

Doctrine\DBAL\Exception\DriverException: An exception occurred while executing 'INSERT INTO "oc_audioplayer_artists" ("user_id","name") SELECT ?,? FROM "oc_audioplayer_artists" WHERE "user_id" = ? AND "name" = ? HAVING COUNT(*) = 0' with params ["ori", "<Really long artist name here>"]: SQLSTATE[22001]: String data, right truncated: 7 ERROR: value too long for type character varying(256)

[Rello]

scanner was adjusted

• values for year & tracknumber are normalized to a positive integer
• strings for e.g. titles, artist, genre are truncated to DB size

#137