{{orphans}} block freezes tab

[ssalka]

Describe the bug On my first usage of {{orphans}}, it made the page unresponsive and was unable to render whatever the result was - it seems to get stuck in processing. High CPU usage can be observed in my browser's task manager.

When this occurs, the only fix is to kill the tab and reload onto a different page otherwise the issue will repeat itself. I've tried waiting several minutes to see if the computation or whatever is hanging resolves, but so far I've had no luck there.

To Reproduce

1. Go to any (?) page
2. Add a new block at the bottom with value {{orphans}}
3. See bug - best to have browser task manager open to observe CPU spike

System Information:

• Device: Macbook Pro (2015)
• OS: Mac OS 10.15.2
• Browser: Brave 1.4.96

Additional context I'm not sure if this applies only to my database or is a general issue, so YMMV when trying to reproduce (for context, I have about 400 pages in total in my database - definitely not at the upper limits of what people are already doing in terms of raw storage).

Video demonstration

• While the example in this video is a dummy page, this is also happening on a real page of mine, and I'm unable to view or edit it! I've also clicked into it a few times and accidentally frozen the page.
  • Edit: I've replaced the page using the markdown from a full export, however this issue was still happening as of 12 May 2020. My guess is I could reproduce it again by adding back the orphans block, but I will not be doing that unless there is an expressed interest in resolving this issue.
• In the video I do not add {{orphans}} directly, but rather embed a block where it is used (in the aforementioned page that I can't access). Adding it directly crashes the page in the same manner.

I also posted about this on the Roam slack

[filipesilva]

@panterarocks49 when this happens on the daily log, the user won't be able to load their roam at all. I think the same also happens with queries.

They'll have to use https://roamresearch.com/#/app/DATABASE_NAME_HERE/search to delete the problem page to load again.

This is related to https://github.com/Roam-Research/issues/issues/108 and https://github.com/Roam-Research/issues/issues/47.