Error body parsing

[atesgoral]

Add minimal reproducible test case for #479

CI should fail.

I'll try to follow up with a fix.

All Submissions:

• Have you followed the guidelines in our Contributing document?
• Have you checked to ensure there aren't other open Pull Requests for the same update/change?
• Have you added an explanation of what your changes do and why you'd like us to include them?

[alexrudall]

Thanks very much for this, @atesgoral - did you have an idea for the fix here?

[atesgoral]

@alexrudall I started looking at a fix a while back, but it didn't turn out trivial due to all the streaming / passing around of blocks. I don't remember the details. But this is something I think is still worth patching!