Can't create first chat file of the day with only append permission

[timbl]

If you happen to the person who makes the first message of the day, and you are a user who has append permission only to the chat space, then you can't create that first file because that requires Write not Append.
(This is not a problem if the message by an owner who created the chat)

[timbl]

Can e in fact solve this by doing a PATCH ... INSERT instead of a PUT to create each chat file -- or do the WAC rules require you to have Write access for that too?

[timbl]

Should we check whether the PUT should in fact have been rejected for those with Append perms?

[timbl]

See https://gitter.im/solid/solidos?at=617cea2798c13e755005f8c8 and following

[timbl]

   createMessageTable for  Fri Oct 29 2021 01:00:00 GMT+0100 (British Summer Time)
mashlib.min.js:8 @@@ SERVER_MKDIRP_BUG: Should only happen once: create chat file: <https://drive.verborgh.org/public/2021/chat/2021/10/31/chat.ttl>
mashlib.min.js:8 createIfNotExists: doc does NOT exist, will create... <https://drive.verborgh.org/public/2021/chat/2021/10/31/chat.ttl>
/public/2021/chat/2021/10/31/chat.ttl:1 Failed to load resource: the server responded with a status of 403 ()
mashlib.min.js:8 createIfNotExists doc FAILED: <https://drive.verborgh.org/public/2021/chat/2021/10/31/chat.ttl>: Error: Web error: 403 on PUT of <https://drive.verborgh.org/public/2021/chat/2021/10/31/chat.ttl>
mashlib.min.js:67 Uncaught (in promise) Error: Web error: 403 on PUT of <https://drive.verborgh.org/public/2021/chat/2021/10/31/chat.ttl>
    at mashlib.min.js:67

[timbl]

Note the @@@ SERVER_MKDIRP_BUG sound like different client code being temporarily put in to compensate. for non-standard Solid servers which do not generate all the intervening directories in the path for a a patch.

[timbl]

Maybe setting SERVER_MKDIRP_BUG to false will fix the problem by replacing the PUT with a PATCH

[RubenVerborgh]

Can e in fact solve this by doing a PATCH ... INSERT instead of a PUT to create each chat file -- or do the WAC rules require you to have Write access for that too?

The access codes we're currently following are https://github.com/solid/specification/issues/14#issuecomment-683480525 (although there are open issues like https://github.com/solid/web-access-control-spec/issues/97 that touch Create).

There, it says indeed that PATCH C/R must return a 200 if the agent has Append and the payload is only INSERT, regardless of whether the resource exists. So that should work!

[csarven]

There, it says indeed that PATCH C/R must return a 200 if the agent has Append and the payload is only INSERT, regardless of whether the resource exists.

Which row are you referring to?

With PATCH, Append on C/R will only update C/R, not create C/R.

PUT and PATCH:

Create requires Append (or Write) on C/ and Write on C/R.

PUT:

Replace requires Write on C/R.

[RubenVerborgh]

@csarven Apologies, I misread; your interpretation is correct. Last row here:

So Append on C.

The Append on C/R case is the topic of https://github.com/solid/web-access-control-spec/issues/97, which is why it works on CSS. Maybe this case is an extra argument of why that should work.