Update stable8.1 to master gives strange error

[PVince81]

Steps

1. Checkout stable8.1 727cb3b
2. Setup OC
3. Check out master 1dc9283
4. Run the upgrade in the web UI

Expected result

Successfull update

Actual result

{"reqId":"Yi0SJKePtbbdziBKljeo","remoteAddr":"192.168.177.239","app":"index","message":"Exception: {\"Exception\":\"OC\\\\NeedsUpdateException\",\"Message\":\"\",\"Code\":0,\"Trace\":\"
#0 \\\/srv\\\/www\\\/htdocs\\\/owncloud\\\/lib\\\/private\\\/app.php(109): OC_App::loadApp('files')\\n
#1 \\\/srv\\\/www\\\/htdocs\\\/owncloud\\\/lib\\\/private\\\/util.php(127): OC_App::loadApps(Array)\\n
#2 \\\/srv\\\/www\\\/htdocs\\\/owncloud\\\/lib\\\/base.php(884): OC_Util::setupFS()\\n
#3 \\\/srv\\\/www\\\/htdocs\\\/owncloud\\\/index.php(40): OC::handleRequest()\\n
#4 {main}\",\"File\":\"\\\/srv\\\/www\\\/htdocs\\\/owncloud\\\/lib\\\/private\\\/app.php\",\"Line\":128}","level":4,"time":"2015-08-25T15:27:23+00:00","method":"GET","url":"\/owncloud\/index.php\/core\/js\/oc.js?v=189e2355831f806ce7399925f50fdf06"}

I noticed that the UI says that the "files" app needs to be updated, maybe something hangs there.
Refreshing the page once and running the update again makes it work.

[PVince81]

The first bad commit could be any of:
36eef2ddabd77ff6279f3bd6896ced4959f1c370
6a3fb0d3b36dce7a6583d58ded1b133f086e2a95
We cannot bisect more!

[PVince81]

Regression introduced through #18482

[PVince81]

Strangely this is the commit that increases the files version later: e88b380 #18510
So not sure if this is related in any way.

[PVince81]

On master if I manually increase the version of "files" and do an app update (web UI), it works.
Also a simultaneous core + files update (increase both versions) starting from master works too.

So there is something happening only when coming directly from stable8.1

[PVince81]

I wonder if this has something to do with routing and loading apps too early.

@LukasReschke @nickvergessen @Xenopathic in case you have an idea

[MorrisJobke]

@PVince81 Is this only about the exception? This exception is logged on every owncloud core upgrade

[PVince81]

Is it ? I didn't notice.

Then it's more about the broken page that appears:

[PVince81]

Reloading will re-show the update page, and then the update can be performed.

Then maybe something is stored in the session which makes the subsequent update work ? That would make sense as the above commits are about the session.

[MorrisJobke]

@PVince81 can you run ./occ upgrade ... the broken page looks like an exception, which is properly logged in the console command.