shr infloop when formatting HTML messages in Gnus

[Eric Abrahamsen]

I get some messages with HTML parts that cause shr to infloop while
formatting. The backtrace shows:

shr-indent()
shr-fill-line()
shr-fill-lines(4125 15335)
shr-insert-document(<document>)

And it hangs there indefinitely. I've looked at the messages and (apart
from a possible correlation that they were sent by Apple's Mail program)
I can't immediately see what's going on.

I'd be happy to forward one of these messages privately, if anyone's
willing to take a look.

Thanks,
Eric