Change etag of folder when the quota of the folder changes

the problem

Currently the client is only creating a PROPFIND request when the etag of folders/files changes. In that request we ask for the properties quota-bytes-available and quota-bytes-used. During the discovery of a new file to upload we try to warn the user of the quota usage when needed based on the quota-bytes-available we got during a PROPFIND.

If the user only got more space and did not touch the folder by deleting files to get more space, the client won't know that the quota changed.
The client will wrongly stop the user from uploading new files even when they have space left in storage because a new PROPFIND was not triggered and information stored in the client is outdated.

solution

Change the etag of folders when the quota changes to make sure the client can update the user of how much quota is left without delays.

@sorbaugh @come-nc @icewind1991 ^^

• https://github.com/nextcloud/desktop/pull/8191
• https://github.com/nextcloud/desktop/issues/4580
• https://github.com/nextcloud/desktop/issues/6971

Start by tracing the server code that generates folder ETags and returns the quota-bytes-available and quota-bytes-used properties. Read the linked pull request 8191 and related issues 4580 and 6971 for context. Done means quota changes cause the folder ETag to change so the client receives updated quota data without requiring file changes.