OC Sharing API removes expiration date when updating a share with a password

[SergioBertolinSG]

Steps to reproduce

1. Share a folder by link.

2. Update the public share adding an expiration date
   2.1 get the shares ids:

   curl -X GET http://USER:PASSWORD@OWNCLOUDPATH/ocs/v1.php/apps/files_sharing/api/v1/shares
   

   2.2 Use the share id for your folder:

   curl -v -X PUT -d expireDate=2015-03-13     http://USER:PASSWORD@OWNCLOUDPATH/ocs/v1.php/apps/files_sharing/api/v1/shares/SHARE_ID
   

3. Add a password

curl -v -X PUT -d password=Manolito http://USER:PASSWORD@OWNCLOUDPATH/ocs/v1.php/apps/files_sharing/api/v1/shares/SHARE_ID

Expected behaviour

A password is added and the expiration date is kept.

Actual behaviour

Password is added and expiration date is lost.

Server configuration

Operating system:
Ubuntu 14.04 LTS

Web server:
Apache

Database:
MySQL

PHP version:
5.5.9

ownCloud version: (see ownCloud admin page)
{"installed":true,"maintenance":false,"version":"8.0.1.1","versionstring":"8.0.1","edition":"Enterprise"}

Updated from an older ownCloud or fresh install:
Updated

List of activated apps:
Default in enterprise version.

The content of config/config.php:

Are you using external storage, if yes which one: local/smb/sftp/...
no

Are you using encryption: yes

Client configuration

*browser
Chrome

[PVince81]

Related: #10671
Setting a password actually creates a new share... so even the token changes.

[PVince81]

@schiesbn

[luciamaestro]

The same problem when you do it from the desktop client

[PVince81]

Setting to 8.1 to keep this in mind @DeepDiver1975 especially that it will affect the clients more in the future.

[rullzer]

So I just ran a few tests and it seems that it even worse.
Even when expiration is enforced. Adding a password removes the expiration date.

So it seems that for some reason we handle adding a password differently from modifying any of the other properties. (permission expire date). I do not really get why we do this (maybe some historic reason?).

If the old expire date is retrieved in https://github.com/owncloud/core/blob/master/lib/private/share/share.php#L668 (which works) and then passed in https://github.com/owncloud/core/blob/master/lib/private/share/share.php#L711 things still break. So it seems like the whole bunch of functions called after that are somewhat broken with respect to adding a password.

I'll see what happens if we just add some logic to update the password in the same way we update the expire date.

[PVince81]

I don't think there is any specific reason for resetting the share when changing the password. It doesn't even make sense.
From what I remember it's just a bug.

[rullzer]

WIP PR in #14868

[MorrisJobke]

Fixed in #14987