Weird behavior if user is in 2 or more groups with one shared folder

[JonesfromHan]

This is a possible duplicate, but I have seen no issue with the exact behavior.

Steps to reproduce

1. Add two Users, User A and User B
2. Add two Groups, Group 1 and Group 2
3. User B has not logged in yet on the server
4. User B is assigned to both Groups
5. User A makes a new folder "WTF" and shares it with both Groups
6. User B logges in for the first time
7. -> Point A
8. User B leaves one Group and then enters again (by himself or admin)
9. -> Point B
10. User A removes the share with and both groups, and then shares again
11. -> Point C

Expected behaviour

The User B should only see the folder one time

Actual behaviour

Point A: He does see only one copy of the folder, even if he is in both groups
Point B: He has now 2 copies of the folder, one time with a (2) behind it. If he marks the secons one (the little hook), it is set on the first copy of the folder
Point C. He sees only one folder

Server configuration

Operating system:
Ubuntu 14.04.3 LTS
Web server:
Apache 2.4.7
Database:
MySQL 5.5.47
PHP version:
PHP 5.5.9
ownCloud version: (see ownCloud admin page)
ownCloud 9.0 beta 1 (daily) Build:2016-02-16T04:41:41+00:00 907430a
Updated from an older ownCloud or fresh install:
fresh
Signing status (ownCloud 9.0 and above):
No errors have been found.

List of activated apps:
Activity
Comments
Deleted files
First Run Wizard
Gallery
Mail Template Editor
Notifications
PDF Viewer
Provisioning API
Share files
System tags
Text Editor
Update Notification
Versions
Video player

The content of config/config.php:

'oc2tuvuc72zw', 'passwordsalt' => '', 'secret' => '', 'trusted_domains' => array ( 0 => 'oc9.domain.tld', ), 'datadirectory' => '/path/web/data', 'overwrite.cli.url' => 'http://oc9.domain.tld', 'dbtype' => 'sqlite3', 'version' => '9.0.0.11', 'logtimezone' => 'UTC', 'installed' => true, ); **Are you using external storage, if yes which one:** no **Are you using encryption:** no **Are you using an external user-backend, if yes which one:** no ### Client configuration **Browser:** Firefox 44.0.2 **Operating system:** Windows 8.1 ### Logs #### Web server error log no error log #### ownCloud log (data/owncloud.log) {"reqId":"YMLj9PF4WqO0SKmsC95z","remoteAddr":"95.90.207.169","app":"PHP","message":"is_readable(): open_basedir restriction in effect. File(\/dev\/urandom) is not within the allowed path(s): (\/var\/www\/clients\/client2\/web19\/web:\/var\/www\/clients\/client2\/web19\/private:\/var\/www\/clients\/client2\/web19\/tmp:\/var\/www\/oc9.boeck.mn\/web:\/srv\/www\/oc9.boeck.mn\/web:\/usr\/share\/php5:\/usr\/share\/php:\/tmp:\/usr\/share\/phpmyadmin:\/etc\/phpmyadmin:\/var\/lib\/phpmyadmin) at \/var\/www\/clients\/client2\/web19\/web\/3rdparty\/paragonie\/random_compat\/lib\/random.php#66","level":3,"time":"2016-02-16T19:29:28+00:00"} Multiple times

[ItsReallyMeDE]

Use case description to understand the impact of this issue:
Assume owncloud use for a set of working groups (WG). A WG corresponds to an owncloud "group".

• Users may obviously be part of multiple WGs
• Assets (Folders, calenders) can be shared with one or several WGs

--> Assigning users to multiple WGs leads to duplicated shared calendars or shared folders as reported above, IFF these assets are shared with multiple WGs.

Very undesirable behavior.

[PVince81]

@rullzer please evaluate severity and whether this is a regression

[ItsReallyMeDE]

@PVince81 we observed the "feature" in 8.2.2 and retested on the latest 9

[rullzer]

Indeed also happens on 8.2.

This basically happens because we check for collison. But if the user never logged in yet there never is collision.

The feature is a bit broken anyway. since if the folder was first shared with group1 and then a recipient moves it to foo and then it is shared with group2 they would still see different shares.

@PVince81 I propose to tackle this properly when we move the internals over to sharing 2.0. So 9.1.
Any fix I can come up with now will be incomplete with the potential to break stuff.