Increase maximum filename size of FileFields

src/pretix/helpers/migrations/0002_auto_20180320_1219.py

@@ -0,0 +1,20 @@
+# -*- coding: utf-8 -*-
+# Generated by Django 1.11.11 on 2018-03-20 12:19
+from __future__ import unicode_literals
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('pretixhelpers', '0001_initial'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='thumbnail',
+            name='thumb',
+            field=models.FileField(max_length=255, upload_to='pub/thumbs/'),
+        ),
+    ]

src/pretix/helpers/models.py

@@ -4,7 +4,7 @@ from django.db import models
 class Thumbnail(models.Model):
     source = models.CharField(max_length=255)
     size = models.CharField(max_length=255)
-    thumb = models.FileField(upload_to='pub/thumbs/')
+    thumb = models.FileField(upload_to='pub/thumbs/', max_length=255)
 
     class Meta:
         unique_together = (('source', 'size'),)