There are people who have RSS feeds set up that do HTTPS -> HTTP
redirects which throw errors. Since RSS feeds are all configured
by admins I think it's OK if they allow an unsafe redirect as the
content is public anyway. This will reduce many server side errors.
We cap new and unread at 2/5th of SiteSetting.max_tracked_new_unread
This dynamic capping is applied under 2 conditions:
1. New capping is applied once every 15 minutes in the periodical job, this effectively ensures that usually even super active sites are capped at 200 new items
2. Unread capping is applied if a user hits max_tracked_new_unread,
meaning if new + unread == 500, we defer a job that runs within 15 minutes that will cap user at 200 unread
This logic ensures that at worst case a user gets "bad" numbers for 15 minutes and then the system goes ahead and fixes itself up
FEATURE: allow backup interval of up to 30 days
FIX: if a custom file exists in backup directory look at its date
FEATURE: site setting automatic_backups_enabled default true
SimpleRss is unreliable with parsing RSS feeds that contain German Umlauts.
For example this feed http://www.lauffeuer-lb.de/api/v2/articles.xml can't be
parsed by SimpleRss. Discourse's logs are full of
```
Job exception: Wrapped Encoding::CompatibilityError: incompatible character encodings: ASCII-8BIT and UTF-8
Job exception: incompatible character encodings: ASCII-8BIT and UTF-8
```
The embedding fails because the feed can't be parsed.
This change forces the encoding (using #scrub) which prevents the numerous
encoding errors.
- new hidden site setting 'migrate_to_new_scheme' (defaults to false)
- new rake tasks to toggle migration to new scheme
- FIX: migrate_to_new_scheme also works with CDN
- PERF: improve perf of the DbHelper.remap method
- REFACTOR: UrlHelper is now a class
FIX: keep the "uploading..." indicator until the server replies via the MessageBus
FIX: text was disapearing when uploading an avatar
PERF: always use a region for S3 (defaults to 'us-east-1')
FEATURE: ApplyCDN middleware when using S3
FIX: use the same pattern to store files on S3 and locally
PERF: keep a local cache of uploads when generating thumbnails
FEATURE: migrate_to_s3 rake task
