Work directly on storage in chunk upload mode

[PVince81]

Follow up from: #12006

This needs to be done for the chunking mode too.

@icewind1991 as discussed here https://github.com/owncloud/core/pull/12006/files#r28233056

@DeepDiver1975 8.1 or 8.2 ?

[karlitschek]

How Intrusive would this be?

[PVince81]

As intrusive as the original fix for non-chunking mode: #12006

[PVince81]

assuming that the part file assembling is the one that goes directly to the storage instead of using the view. It shouldn't be too different to the other one. It's just that the code is partly duplicated in other places.

[PVince81]

Looks like we might need this for the files locking to work, to avoid double locking.

[PVince81]

@icewind1991 didn't you have a PR for this already ? Or maybe I mixed it up with something else.

[icewind1991]

#17811 does chunk assembly direct on the storage

[PVince81]

Right, that was the one. I was confused because it combined the lock fix as well.

Closing.