Issue with share included in Hubzilla forum post

Tue, 16 Feb 2021 06:46:56 -0800

@!Zotlabs|Hubzilla Development @!Hubzilla Support Forum
I posted in a #Hubzilla Forum Channel with the @!-Tag.
In the post, I included a [share][/share]-snippet, containing a post ID.

Unexpected behavior (The post on my channel and on the forum channel don't look the same):

The post title is not showed in the forum.
My icon and name are not shown in the forum.
All text before the [share][/share]-snippet is not shown in the forum

Can anybody reproduce this behavior? Has this to do with the new protocol?

Mario Vavti

Tue, 16 Feb 2021 07:00:09 -0800

Yes, that is a limitation currently. You can not post a share to a forum. IIRC only the share will be re-posted by the forum.

It will require some investigation if this limitation is still required.

emanuel @ la bonne heure

Fri, 05 Mar 2021 06:38:17 -0800

Thank you @Mario Vavti for the answer.

if this limitation is still required

So do I get it right that this is a feature and there was a requirement for it? Was there a discussion that I missed in which this was decided as a requirement (maybe during development of zap)?

It will require some investigation

Is it a priority? How are you imagining this investigation? Are you coordinating this investigation, or who? Can I contribute? Should I start a poll among the users and developpers?

Zap

Fri, 05 Mar 2021 13:32:19 -0800

Long story.

We have traditionally supported multiple inline shares, so you can for instance share several posts in a singe post. What we did not support is recursion, where the item shared was itself a share. The reason for this is that if you allow recursion, you must also limit it from endless recursion. It is an oversight that this work was not done in 2010 when the bbcode parser was developed. It was not done at the time because in that earlier era the software was much less complex and didn't support or provide any tag recursion. The needs for tag recursion support have grown as the project has grown and evolved and these have been added on a case-by-case (tag by tag) basis as they were encountered.

These introduce enormous complexity, and complexity is often the enemy of reliability and maintainability.

So in order to make this construct work, the first task is to go back to the bbcode rendering code and provide recursion for this particular tag, along with a recursion limit, and then test the heck out of it. Since this tag contains a number of sub-elements, the testing matrix and number of things that can go wrong grow exponentially as each recursion level is added.

For instance, when we import any post from anywhere, we need to look up the author on the web and create a global channel record (xchan) for them. Diaspora did this with shared content and created a situation we call the '"recursive reshare from hell" which breaks the entire share chain if any element in the chain can't be fetched at the exact point in time you need it. It can also loop indefinitely and kill your server. We tried not to repeat these mistakes, because in the real world it breaks all the time. So recursive shares were banished. It seemed like the right thing to do at the time given the bad experiences with Diaspora's recursive implementation. Luckily, our earlier work on shares was executed correctly and this particular tag carries ALL the information we require to import the post without fetching anything from the outside world. We were not certain this would be the case and was pleasantly surprised to find out we can actually make it work without falling into the "recursive reshare from hell" trap.

Then in the group/forum delivery code we can remove the bit that tries to do something besides crash and burn if this construct is encountered. So it was always anticipated that somebody would attempt this construct, but we tried to work around it as it was not officially supported. In this case it actually turned out to be easier to support it than try to work around it, but we needed to do all the hard work to make this determination.

Mario Vavti

Fri, 05 Mar 2021 06:40:40 -0800 last edited: Fri, 05 Mar 2021 06:41:53 -0800

This should be fixed in the upcoming release 5.4