Sharing pane overwrites current owner

Did this always happen? It seems pretty big.

To Replicate:

• In the databrowser, create a new file in, say, the private folder (https://jackson.localhost:8443/private/test.txt)
• Once you do that, the private folder has two resources (https://jackson.localhost:8443/private/test.txt and https://jackson.localhost:8443/private/.acl - the private folder's default acl, seen below)

# ACL resource for the private folder
@prefix acl: <http://www.w3.org/ns/auth/acl#>.

# The owner has all permissions
<#owner>
    a acl:Authorization;
    acl:agent <https://jackson.localhost:8443/profile/card#me>;
    acl:accessTo <./>;
    acl:defaultForNew <./>;
    acl:mode acl:Read, acl:Write, acl:Control.

• At this point, everything's good. text.txt inherits its permissions from private's acl.
• Go to the sharing pane and click "Set specific sharing preferences"
• This will cause a new file (https://jackson.localhost:8443/private/test.txt.acl) to be made (see below)

@prefix : <#>.
@prefix acl: <http://www.w3.org/ns/auth/acl#>.
@prefix c: </profile/card#>.

:owner
    a acl:Authorization;
    acl:accessTo <test.txt>;
    acl:agent c:me;
    acl:mode acl:Control, acl:Read, acl:Write.

• Everything's still fine because it adds c:me to the acl.
• Now, click the green plus and the single person icon to add a new user.
• Add another webid like https://ldp.demo-ess.inrupt.com/114176645321964550648/profile/card#me
• This updates https://jackson.localhost:8443/private/test.txt.acl to be below

@prefix : <#>.
@prefix n0: <http://www.w3.org/ns/auth/acl#>.
@prefix c: <https://ldp.demo-ess.inrupt.com/114176645321964550648/profile/card#>.

:Read a n0:Authorization; n0:accessTo <test.txt>; n0:agent c:me; n0:mode n0:Read.

• Notice that instead of adding the new user, it fully replaced the original owner of the document.

Start with the sharing pane flow triggered by “Set specific sharing preferences” and the green-plus user addition. Trace how the existing ACL is updated when a new WebID is added; done means the new user is added while the current owner and existing permissions remain. Reproduce the steps in the issue to verify the resulting ACL.